[House Hearing, 112 Congress]
[From the U.S. Government Publishing Office]
[H.A.S.C. No. 112-154]
F-22 PILOT PHYSIOLOGICAL ISSUES
__________
HEARING
BEFORE THE
SUBCOMMITTEE ON TACTICAL AIR AND LAND FORCES
OF THE
COMMITTEE ON ARMED SERVICES
HOUSE OF REPRESENTATIVES
ONE HUNDRED TWELFTH CONGRESS
SECOND SESSION
__________
HEARING HELD
SEPTEMBER 13, 2012
[GRAPHIC(S) NOT AVAILABLE IN TIFF FORMAT]
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SUBCOMMITTEE ON TACTICAL AIR AND LAND FORCES
ROSCOE G. BARTLETT, Maryland, Chairman
FRANK A. LoBIONDO, New Jersey SILVESTRE REYES, Texas
JOHN C. FLEMING, M.D., Louisiana MIKE McINTYRE, North Carolina
TOM ROONEY, Florida JIM COOPER, Tennessee
TODD RUSSELL PLATTS, Pennsylvania NIKI TSONGAS, Massachusetts
VICKY HARTZLER, Missouri LARRY KISSELL, North Carolina
JON RUNYAN, New Jersey MARTIN HEINRICH, New Mexico
MARTHA ROBY, Alabama BILL OWENS, New York
WALTER B. JONES, North Carolina JOHN R. GARAMENDI, California
W. TODD AKIN, Missouri MARK S. CRITZ, Pennsylvania
JOE WILSON, South Carolina KATHLEEN C. HOCHUL, New York
MICHAEL TURNER, Ohio JACKIE SPEIER, California
BILL SHUSTER, Pennsylvania
DOUG LAMBORN, Colorado
John Sullivan, Professional Staff Member
Doug Bush, Professional Staff Member
Scott Bousum, Staff Assistant
C O N T E N T S
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CHRONOLOGICAL LIST OF HEARINGS
2012
Page
Hearing:
Thursday, September 13, 2012, F-22 Pilot Physiological Issues.... 1
Appendix:
Thursday, September 13, 2012..................................... 35
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THURSDAY, SEPTEMBER 13, 2012
F-22 PILOT PHYSIOLOGICAL ISSUES
STATEMENTS PRESENTED BY MEMBERS OF CONGRESS
Bartlett, Hon. Roscoe G., a Representative from Maryland,
Chairman, Subcommittee on Tactical Air and Land Forces......... 1
Reyes, Hon. Silvestre, a Representative from Texas, Ranking
Member, Subcommittee on Tactical Air and Land Forces........... 3
WITNESSES
Cragg, Clinton H., Principal Engineer, National Aeronautics and
Space Administration (NASA) Engineering and Safety Center...... 11
Lyon, Maj Gen Charles W., USAF, Director of Operations,
Headquarters Air Combat Command, U.S. Air Force................ 7
Martin, Gen Gregory S., USAF (Ret.), Aircraft Oxygen Generation
Study Chair, USAF Scientific Advisory Board.................... 4
APPENDIX
Prepared Statements:
Bartlett, Hon. Roscoe G...................................... 39
Cragg, Clinton H............................................. 99
Lyon, Maj Gen Charles W...................................... 60
Martin, Gen Gregory S........................................ 46
Reyes, Hon. Silvestre........................................ 42
Documents Submitted for the Record:
[There were no Documents submitted.]
Witness Responses to Questions Asked During the Hearing:
Ms. Speier................................................... 105
Questions Submitted by Members Post Hearing:
Mr. Bartlett................................................. 109
Mr. Loebsack................................................. 116
Mr. Runyan................................................... 113
Ms. Speier................................................... 115
F-22 PILOT PHYSIOLOGICAL ISSUES
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House of Representatives,
Committee on Armed Services,
Subcommittee on Tactical Air and Land Forces,
Washington, DC, Thursday, September 13, 2012.
The subcommittee met, pursuant to call, at 10:02 a.m., in
room 2118, Rayburn House Office Building, Hon. Roscoe G.
Bartlett (chairman of the subcommittee) presiding.
OPENING STATEMENT OF HON. ROSCOE G. BARTLETT, A REPRESENTATIVE
FROM MARYLAND, CHAIRMAN, SUBCOMMITTEE ON TACTICAL AIR AND LAND
FORCES
Mr. Bartlett. The hearing will come to order. The
subcommittee meets today to receive testimony on F-22 pilot
physiological issues which have resulted in reported hypoxia-
like events by F-22 pilots over a period of several years.
The committee's concerns include the impacts of these
physiological issues to the pilots and operational capability
of these valuable aircraft, as well as the ultimate cost and
time required to implement the recommendations that have been
made to modify the F-22 life support system.
The committee also remains concerned that after all of the
study of the issue, we need to understand what the level of
confidence is that the cause or causes of the F-22
physiological issues are fully known.
From 2003 to April 2008, there were 6 F-22 physiological
issues, but between April 2008 and January 2011, that number
had doubled to 12. As a result of this, the Air Force Commander
of Air Combat Command restricted the F-22's maximum flight
attitude to 25,000 feet and directed a safety investigation
board to review the F-22's oxygen system.
In May of 2011, the Secretary of the Air Force directed the
Scientific Advisory Board to gather information and make
recommendations to address concerns relative to the F-22 life
support system. From May to September of last year, the F-22
fleet stood down as a result of an upward trend in reports of
physiological incidents. The Scientific Advisory Board [SAB]
completed its work in January of this year but did not
determine a cause for the F-22 pilot physiological problems.
However, the board did make findings and recommendations and
concluded that either the supply or the quality of the oxygen
is contributing to the F-22 pilots' hypoxia-like symptoms.
Air Combat Command established a Life Support System Task
Force, which continued to examine both the issues of supply and
quality of oxygen in the F-22. On April 23, 2012, the National
Aeronautics and Space Administration, NASA, accepted a request
from the Air Combat Command to form an independent
investigative team to review Air Combat Command's investigative
process, ongoing root cause analysis, and the F-22 life support
system as a whole to determine potential vulnerabilities to the
pilot.
On July 24th, the Department of Defense announced that Air
Combat Command had determined that the root cause of the F-22
pilot physiological issues is the supply of oxygen delivered to
the pilots, not the quality of oxygen delivered to the pilots.
To correct the supply issue and reduce the incidence of
related hypoxia-related events, the Air Force has made two
changes to the aircraft's cockpit life support system. First,
the Air Force has increased the volume of air flowing to pilots
by removing a filter that was installed as a part of the
investigation to determine whether there were any contaminants
present in the oxygen system. Second, the Air Force will
replace a valve in the upper pressure garment worn by pilots
during high-altitude missions. The upper pressure garment is
designed to provide counterpressure to assist pilots' breathing
and to help counteract the effects of G-forces. The garment
valve was causing the vest to inflate and remain partially
inflated under conditions where it was not designed to do so,
thereby causing breathing problems for some pilots. Oxygen
contamination was ruled out as potential cause.
The Air Force is also exploring ways to improve the oxygen
delivery hose and its physical connections.
In the interim, the F-22 is under a temporary altitude
limit of 44,000 feet. Since the F-22 returned to flying status
in September of 2011, there have been 11 hypoxia incidents
where the incidents were initially reported as cause unknown.
The Air Force continues to investigate these incidents, and as
of late July, less than half of those were still unresolved.
There have been no cause unknown hypoxia incidents in the
F-22s since March of 2012.
From fiscal year 2002 to May 2011, the Air Force reports an
incidence rate of 13 hypoxia events per 100,000 hours compared
to 7.5 in the F-16, and 1.8 in the F-15E, and 6.6 in the F-18E,
F and G, over roughly the same period.
I know from personal experience as a scientist working with
these issues before I came to Congress that the Air Force faced
a difficult problem in determining the root cause of these 22
pilot hypoxia-like events because symptoms of hypoxia and
hypocapnia, also know as hyperventilation, are very difficult
to distinguish. Indeed, pilot concerns about hypoxia will
frequently result in hyperventilation, imperceptible to the
pilot, which will produce hypoxia-like symptoms, eliciting even
more hyperventilation, a vicious cycle.
A significant amount of effort has gone into solving the F-
22 physiological issues, but much more needs to be done.
Recommendations of the Air Force Scientific Advisory Board's
Oxygen Generation Study Group needs to be implemented. The Air
Force Air Combat Command Life Support Systems Task Force needs
to complete its report and provide its final recommendations.
Additionally, NASA's Engineering and Safety Center needs to
complete final report and provide its recommendations. The
committee expects the Air Force to keep Congress up to date on
the status of all of these reports and recommendations.
To address the F-22 physiological issues, we have asked the
three key leaders involved in this project to testify today:
Retired Air Force General Gregory S. Martin, Chairman of the
Air Force Scientific Advisory Board Quick Look Study on
Aircraft Oxygen Generation.
General Martin, welcome back.
Major General Charles Lyon, Director of Operations for the
Air Combat Command. General Lyon leads the F-22 Life Support
System Task Force.
Finally, Mr. Clinton H. Cragg, principal engineer at NASA's
Engineering and Safety Center. Mr. Cragg leads NASA's
independent investigative team, which has reviewed Air Combat
Command's F-22 processes and analyses.
Gentlemen, we thank you all for your service to our
country.
Before we begin, let me call on the ranking member of the
subcommittee, Mr. Reyes, for his opening remarks.
[The prepared statement of Mr. Bartlett can be found in the
Appendix on page 39.]
STATEMENT OF HON. SILVESTRE REYES, A REPRESENTATIVE FROM TEXAS,
RANKING MEMBER, SUBCOMMITTEE ON TACTICAL AIR AND LAND FORCES
Mr. Reyes. Thank you, Mr. Chairman.
And let me add my welcome to you this morning, gentlemen.
From a personal perspective, I want to thank the Chairman
because as a scientist, he was able to explain some of these
very difficult technical issues with the problem that we have
been wrestling with now with the oxygen system of the F-22.
So, Mr. Chairman, I wanted to thank you publicly for--on
this committee, for having the expertise to be able to do that,
and thank you for your leadership as well.
Today's hearing on the F-22 will cover many technical
issues, as I mentioned, that have been associated with the F-
22's pilot life support system. On balance, I am pleased with
the level of effort that the Air Force has put into this
investigation. It is clear that the current senior Air Force
officials have taken this issue very seriously and have put in
place the necessary resources and organizations needed to
identify the problem and eventually to get to a place where we
fix this problem.
The scale of the testing and the evaluation effort for a
tactical fighter aircraft is, from my view point,
unprecedented. Rather than staying in a defensive posture, the
Air Force reached out to other agencies and other military
services for additional expertise and for advice. Based on the
extensive work done by the Air Force and other DOD [Department
of Defense] agencies, I am cautiously optimistic that the Air
Force has indeed identified the primary causes of the hypoxia
problems with the F-22, has identified fixes that, from a
layman's perspective, seemed to make sense.
The next step is ensuring that the fixes identified are
funded and installed as rapidly as possible. The United States
clearly needs the F-22 to deter our enemies and to provide
critical capabilities if we go to war. Despite Congress passing
a long-term continuing resolution for defense spending, I
personally want to ensure that efforts to fix the F-22 problems
can continue at full speed.
So understanding the F-22's problems and how to fix them is
one aspect of today's hearing and a very important one.
However, the larger issue that I hope today's hearing will
touch on is how this situation occurred in the first place, and
how we avoid similar mistakes going forward.
As far as the cause of the F-22's problems, my overall
impression from the testimony that we have received and other
information provided to our committee is that the main problems
with the F-22 were human failures of judgment and not technical
failures.
One issue that appears to have gone wrong was a basic
design of the aircraft's life support system. The F-22 is the
most capable and, I should add, expensive fighter aircraft ever
developed. The F-22 also operates at higher altitudes and in a
more demanding performance envelope, perhaps more than any
other fighter in the history of this country. Given these two
factors, a cost per plane of more than $140 million and a
unique flight environment, it is very surprising that it was
designed, again from a layman's perspective, with--designed
without a sophisticated backup oxygen system or even enough
instrumentation to let the pilot know that he wasn't getting
oxygen in time to actually do something about it.
So one question that confronts the subcommittee is, how did
that happen? Why did the Air Force design and build such a
sophisticated aircraft with such a relatively unsophisticated
pilot oxygen support system?
In addition, why wasn't this issue identified during
testing of the aircraft? That is normally when serious design
issues are identified for future fixes. But that doesn't seem
to have been the case with the F-22.
We are going to get a lot of information today, but in
particular, I look forward to hearing from the Air Force
witnesses and, again, welcome, how they think we got to this
point and how we can avoid similar problems with other aircraft
in the future.
And with that, Mr. Chairman, I want to yield back to you.
[The prepared statement of Mr. Reyes can be found in the
Appendix on page 42.]
Mr. Bartlett. Thank you very much.
Without objection, all witnesses' prepared statements will
be included in the hearing record.
General Martin, please proceed with your opening remarks.
You will be followed by General Lyon and Mr. Cragg.
STATEMENT OF GEN GREGORY S. MARTIN, USAF (RET.), AIRCRAFT
OXYGEN GENERATION STUDY CHAIR, USAF SCIENTIFIC ADVISORY BOARD
General Martin. Thank you, Mr. Chairman.
Chairman Bartlett and Ranking Member Reyes and other
distinguished members of this committee, I am honored to be
here today representing the members of the Air Force Scientific
Advisory Board Study Panel on Aircraft Oxygen Generation
Systems.
During my remarks and during my responses to any questions
that I receive, I will try to answer the questions as I believe
the members of the study panel would answer them, as opposed to
my own personal views.
The onboard oxygen generation system [OBOGS] on the F-22 is
very similar to other onboard oxygen generation systems that we
have on many fighter aircraft. And they were designed to reduce
the servicing, logistic support and safety--and increased
safety considerations. The F-22 aircraft is equipped with such
a system to provide breathing air to the pilot, and this system
usually, in the F-22 as well as the other aircraft, will take
bleed air off of the engine, concentrate it into a higher level
of oxygen and then match that amount of oxygen to the breathing
air, based on the cabin pressure and altitude.
Beginning in 2008, as the chairman pointed out, the F-22
began to experience a significantly higher rate of hypoxia-like
incidents with unknown causes, as reported by the pilots. At
that point, the Air Force initiated what I will refer to as a
four-tier approach to finding the root cause for these
unexplained physiological incidents. The first tier was a
collaborative effort between the F-22 system program office,
the prime contractor and its key subcontractors responsible for
the components of the F-22 life support system, and the normal
Air Force safety investigation structure. So that collaborative
effort started a process we have come to know as the Root Cause
and Corrective Action [RCCA] analysis process that has
continued for the last 4\1/2\ years.
The second tier was initiated after preliminary results of
the tragic fatal F-22 mishap that occurred in November of 2010.
When that mishap was out-briefed to the senior leadership in
January of 2011, the Air Combat Command established a Class E
safety investigation mishap board. That board was chaired by an
Air Force Major General, and it was chartered to review all F-
22 reported hypoxia-like incidents. So, in conjunction with the
RCCA team, or the Root Cause and Corrective Action Analysis
Team, this safety investigation team developed and implemented
a multitude of tests and challenges to each of the F-22s life
support system components.
At that time, the F-22 flight operations were limited to
25,000 feet and the pilots were directed to fly in the maximum
oxygen production mode, known as max. These directions were
provided to minimize the opportunity for any of the crews to be
exposed to an environment that could cause hypoxia-like
symptoms, so lower altitude and use of 100 percent oxygen
direction was given to prevent or preclude future hypoxia-like
incident. Nonetheless, there was an increase in the number of
hypoxia-like events. And after two troubling incidents in May
of 2011, the Air Force grounded the fleet of F-22 aircraft. At
that point, the Safety Investigation Board, which had been
unable to determine a failure mode that might lead to the
hypoxia-like events, recommended that the Air Force modify one
of its test aircraft with a specialized array of sensors and
then execute a carefully developed series of flight test
profiles to determine if the root cause could be assessed in
the dynamic flight environment as opposed to the ground testing
that had been done to that point.
Further, as a part of their investigation, the Safety Board
determined there were decisions made during the engineering,
manufacturing and development phase of the F-22's development
that should be reviewed from a broader perspective, and they
recommended a broad area review of the F-22 program be
conducted. So, in June of 2011, the Secretary of the Air Force
and the Chief of Staff of the Air Force tasked the United
States Air Force Scientific Advisory Board to perform a quick-
look study on aircraft oxygen generation systems and to cover
three areas: First, continue the ongoing efforts to determine
the root cause, to include gathering data during dynamic in-
flight testing, full reviews of both the life support equipment
and the aircraft's potential for passing contaminants into the
cockpit and/or the breathing air, and finally, to better
understand the similarities and differences between the F-22
oxygen generation system and other military aircraft; second,
to better understand the conditions that would create hypoxia-
like symptoms at altitudes not normally associated with
hypoxia, along with an evaluation of the guidance associated
with breathing air standards and the human response to
operating in the F-22's extraordinary envelope with less than
90 percent supplied oxygen; third, to review the policies,
processes and procedural changes that occurred during the F-
22's development and fielding phase to evaluate the
implications with respect to design limitations, risk analysis,
program execution and the acquisition workforce.
The study began in June of 2011, with interim status
reports provided to Secretary and the Chief until the final
briefing was approved by the entire Scientific Advisory Board
and delivered to the Secretary and the Chief on the 24th of
January 2012. This activity actually represents the third tier
of effort in determining root causes.
It is important to note that SAB study panel recognized
from some initial statistical analysis that it was quite likely
that in the initial flight test profiles conducted during the
summer of 2011, that we may not determine the root causes in
that limited sample of flight. With that in mind, it became
clear that it would need to develop or help the Air Force
develop an appropriate risk-mitigation procedure to allow the
F-22 fleet to return to flight operations in a safe mode that
would provide the Nation with its critical combat capabilities
while at the same time offering Air Force--the Air Force the
ability to collect and analyze the voluminous amount of data
that would be collected during these flights and to continue
their investigation in determining root causes for the
unexplained physiological incidents.
As a result, the SAB study manual was able to develop a
protocol of aircraft inspections, crew training, crew
protection devices and procedures, along with a specific series
of incident response protocols to assist the Air Force in
zeroing in on the root causes or root causes. With that in
mind, the Air Force chose to resume F-22 flight operations in
September 2011.
Between that time and the AFSAB, or the Scientific Advisory
Board's, out-brief to the Secretary and to the Chief in January
2012, the AFSAB continued to assess and evaluate data from
approximately 7,500 sorties. As a result of analyzing the
emerging stream of data, the study panel completed its study
effort and made recommendations to the Air Force leadership in
third areas that would, one, in the near term, allow the Air
Force to complete its root-cause analysis and safely return the
F-22 to its full operational flight envelope; two, over the
next several years, modify the aircraft and develop specific F-
22 tools to improve the margin of safety related to the F-22's
entire life support system design and performance and develop
procedures related to the human system's integration process
that the Air Force uses to further explore the interaction
between the human and the F-22 in all of its environment. They
also directed that the Air Force take the lead in establishing
comprehensive aviation breathing air standards applicable to
the environments in which all of its aircraft would operate.
The key to implementing the AFSAB study panel
recommendations was determined to be the establishment of a
task force to continue the data-gathering and analysis process
initiated by the AFSAB study panel, while at the same time
developing the implementation plans to finalize and close out
the remaining recommendations. Standing up this task force,
which has been directed by Major General Lyon, next to speak,
represents the fourth tier of the Air Force's overall effort to
find the root causes to the unexplained physiological
incidents.
As a final note, I would mention that the study panel did
recommend a quarterly follow-up be established to review the
process on completing the recommendations and that the AFSAB
would be available for support, if required. To date, the task
force has completed two quarterly follow-ups and presented
their reports to the AFSAB. And their progress has been
impressive.
In summary, I believe this four-tier approach, coupled with
the Air Force's request from NASA for an independent assessment
of their process and their recommendations represents that the
Air Force is dedicated to being thorough, credible and
transparent in its approach to solving this difficult issue.
This completes my initial statement, and I look forward to
your questions.
[The prepared statement of General Martin can be found in
the Appendix on page 46.]
Mr. Bartlett. Thank you very much.
General Lyon.
STATEMENT OF MAJ GEN CHARLES W. LYON, USAF, DIRECTOR OF
OPERATIONS, HEADQUARTERS AIR COMBAT COMMAND, U.S. AIR FORCE
General Lyon. Chairman Bartlett, Ranking Member Reyes,
distinguished members of the committee, thank you for the
opportunity today to discuss an issue of great importance to
the United States Air Force, the F-22 pilot physiological
issue.
Mr. Chairman, I would like to thank you for the steadfast
leadership of this committee and to your members for their
unwavering support and commitment to the men and women of the
United States Air Force and the entire Department of Defense.
This committee has helped ensure our men and women are equipped
and resourced to meet the responsibilities in support of
national security objectives at home and abroad over the years.
The F-22 Raptor contributes significantly to our Nation's
interest vital interest by providing air dominance when and
where ordered to protect and enable the joint military force.
Today, we have F-22s forward deployed to support the objectives
of geographic combatant commanders in the Central Command, and
Pacific Command areas of operations. This forward presence
reassures our allies, enhances joint and coalition
interoperability, and demonstrates our resolve for lasting
global relationships.
We also have continental United States based F-22s
contributing to homeland defense, while the remainder of the
fleet conducts combat-mission-ready training, formal
replacement unit training and operational test and evaluation.
The F-22's attributes, stealth, supercruise,
maneuverability, and integrated avionics, ensure our ability to
project power anywhere on the globe, including anti-access and
area denial environments. Simply stated, the F-22 fleet,
combined with complementary capabilities from our joint
partners, allows us to kick down the door and enable joint
operations in the most demanding environments that exist now
and in the foreseeable future. The F-22's multi-mission
capabilities allow us to seize the initiative, achieve air
superiority, attack those who challenge us in the skies, and to
defeat those who would challenge us from the ground. The F-22
contributes significantly to protect the joint force from
attack, while enabling the joint force to conduct offensive
operations.
The capabilities of the F-22 weapon system are compelling,
but without the contributions of the men and women who fly, fix
and support F-22 operations, the Raptor would never leave the
ground. Flying high-performance fighter aircraft is not risk-
free. But the risk is measured against mission priorities and
probabilities of success. Just as other airmen and members of
the joint force accept risk in the conduct of their daily
military duties, we accept risk in operating the F-22.
To set the context for this issue's history, as the
chairman said, F-22 fleet experienced six physiological
incidents in our initial phases over a 5-year period. The
number of incidents more than doubled in the next 3 years. The
increased number of incidents in 2008 to 2011, the ambiguities
and uncertainties at the time surrounding Captain Haney's
November 2010 tragic and fatal mishap, and the unexplained
nature of these incidents gave the Air Force grave concern,
which prompted the fleetwide standdown in May 2011.
Although the total percentage of physiological incidents at
the time of the standdown represented less than 0.1 percent of
all sorties flown to date, that wasn't good enough, and it did
not meet our service established safety standards. The risk to
the safety of our airmen posed by uncertainty and ambiguity
exceeded our threshold.
During the standdown, the Air Force expanded analytic
capabilities beyond the use of normal governmental resources to
include additional expertise from the public and private
sectors. After months of research, testing, and analysis,
General Martin's study group provided a set of recommendations
to the Air Force September of last year. This put us on the
path to safely return the F-22 fleet to flight operations with
an acceptable level of risk.
The recommendations were reviewed and implemented with the
F-22 fleet returned to flying just under a year ago, September
21st, 2011. Between September 2011 and today, the Air Force has
continuously analyzed the previously unexplained physiological
incidents, implemented and adjusted risk-mitigation measures,
and incorporated corrective actions to enhance the safety of
the F-22 Raptor fleet.
General Martin's study group completed their investigative
actions in January of this year. Following General Martin's
presentation to Air Force leaders, the Secretary of the Air
Force formed the F-22 Life Support Systems Task Force, led by
me, to continue this analytic effort and implement corrective
actions. Our integrated, collaborative, multi-service, cross-
functional, government/industry team approach permitted an
increased breadth of experience, enhanced scope of knowledge
and provided additional and partial expert analysis, which was
critical in the determination of root causes. The task force
has considered the inputs, findings and recommendations of the
previously convened F-22 Safety Investigation Boards,
Scientific Advisory Board and Lockheed Martin's Root Cause and
Corrective Analysis Team. We have integrated their findings,
continued the investigative process, and drawn conclusions that
could not have been reached without the benefit of this
collaborative approach.
The previously unexplained F-22 physiological incidents
were the result of multifactorial combinations. The trend over
time has eliminated system-specific factors related to oxygen
delivery system components. During our analysis timeframe,
Major Dr. Marsha Mitchum, seated behind me, an F-22 flight
surgeon at Joint Base Langley-Eustis, conducted independent
research with Duke University and the Naval Surface Warfare
Center in Panama City, Florida. Through her efforts and
coordination, the naval experimental dive unit became involved
to offer an assessment on life support issues and breathing
devices. This research opened a door for new analysis that had
not been addressed to this point in our Air Force investigative
process. This would turn out to be a decisive moment for F-22
investigative efforts.
We convened an F-22 Restrictive Breathing Working Group at
Langley in April of this year. The task force facilitated this
session, lead by Lieutenant Colonel Jeff Hawkins, seated behind
me, from the First Fighter Wing, an F-22 pilot. This group
consisted of F-22 pilots, engineers, medical and safety
professionals from the Air Force, Air Force Combat Command, Air
Force Materiel Command; from the Navy, both the Experimental
Dive Unit, their Surface Warfare Center; Naval Air Systems
Command [NAVAIR] from NASA, Wyle Labs, Lockheed Martin and
Boeing, an impressive group of professionals gathered together
to work this issue.
Additionally, the task force sought NASA's assistance to
review our post-incident protocols and, if warranted, recommend
enhanced procedures with a greater emphasis on integrated life
support systems and cabin pressurization systems analysis.
Concurrently, we requested that NASA form an independent team
to review our investigative process in the entire F-22 life
support system to determine potential vulnerabilities to the
pilot.
The NASA Engineering and Safety Center [NESC] provided that
team, lead by Mr. Clint Cragg, sitting here to my left here
today. I would like to thank Mr. Cragg and his team for their
unique insight and contributions to our efforts. Two weeks ago,
Mr. Cragg presented his findings and recommendations to me for
incorporation in our analysis.
While corroborating much of what we had researched, the
team also presented additional measures for our consideration.
The task force is confident that data derived from General
Martin's group hypothesis one, oxygen quantity, describes the
major contributors to the previously unexplained physiological
incidents reported by F-22 pilots over the past few years. The
task force is confident that the hypothesis two, oxygen
quality, is not the root cause of previously unexplained
physiological symptoms reported by F-22 pilots and ground crew.
Systemic factors in the life support system, such as the
Combat Edge upper pressure garment and the C2A1 filter
functionalities, have been identified, removed and corrective
action is underway. We have reduced the potential negative
affects created by high oxygen concentration levels produced by
the OBOGS through cockpit selectable oxygen sittings.
Human factors at two F-22 operating locations were
contributory. We have communicated findings and corrective
actions to the community. This communication has reduced the
ambiguity and uncertainty, while significantly increasing pilot
and ground crew confidence in the F-22's life support systems.
Mr. Chairman, we have more work ahead as we transition to
normal F-22 flight operations. The path to resuming normal
flight operations hinges on the successful development,
testing, and fielding of the modified Combat Edge upper
pressure garment valve. This modification will successfully
integrate the key components of the F-22 life support system to
ensure adequate oxygen flows to the pilot, while providing
protection in the high-altitude and high-G environments where
the F-22 flies. We expect this modification to be fielded by
the end of 2012.
I have had the opportunity to present task force interim
findings, recommendations, and corrective actions to Department
of Defense and Department of the Air Force senior leaders
throughout this investigation. Department leaders have
expressed keen interest to fixing the F-22's life support
system vulnerabilities, to maximize the safety of the men and
women who operate and maintain this aircraft, and have provided
us the required resources and support to bring this issue to
conclusion. The fielding of the automatic backup oxygen system
will provide additional protection to F-22 pilots while flying
at high altitude and under the most demanding oxygen delivery
system scenarios that can be envisioned for the F-22 lifecycle.
We expect the first operation aircraft will be modified in
January 2013, the first operational squadron complete by the
spring of 2013, and the entire fleet complete by mid 2014. We
are certain the F-22 cockpit and surrounding workspace is a
safe, effective place to operate, but the Air Force is an
organization that is built on the foundation of innovation,
self-improvement, and ingenuity. Continuous process
improvements will ensure the safety of the F-22 workforce now
and in the future.
To date, since we resumed flight operations last September,
we have flown nearly 20,000 sorties, totalling over 25,000
hours, while encountering 11 previously unexplained in-flight
incidents and 6 ground-related physiological incidents. None of
these incidents have resulted in the loss of life, loss of
aircraft control, nor lingering effects for our pilots and
ground crews. Importantly, we have not encountered an
unexplainable incident since March 8 of this year. Since that
time, we have flown more than 10,000 sorties, totalling over
13,000 hours, without incident. The trend is on a positive
vector not seen in years.
There will be physiological incidents in the future. The
harsh high-altitude, high-G environment is extremely demanding,
and our pilots are aware of those demands. We encounter
physiological incidents in all high-performance aircraft--it is
a fact of life--due to the demands placed on our air crew. The
measures taken by the Air Force, in my opinion, will reduce the
incident rate significantly and over time bring the F-22
incident rates in line with comparable high-performance
aircraft. The Air Force is committed to implementing these
changes to return the F-22 to normal operations, thus
significantly contributing to our Nation's vital interests by
providing air dominance when and where ordered to protect and
enable the joint U.S. military force. The Air Force will
continue to leverage lessons learned throughout this
investigative process, and will invest in characterizing and
understanding the high-performance aircraft environment to
optimize pilot performance, not only in the F-22 but in all
current and future weapon systems.
Mr. Chairman, I look forward to answering your questions.
[The prepared statement of General Lyon can be found in the
Appendix on page 60.]
Mr. Bartlett. Thank you.
Mr. Cragg.
STATEMENT OF CLINTON H. CRAGG, PRINCIPAL ENGINEER, NATIONAL
AERONAUTICS AND SPACE ADMINISTRATION (NASA) ENGINEERING AND
SAFETY CENTER
Mr. Cragg. Chairman Bartlett, Ranking Member Reyes, members
of the subcommittee, thank you for this opportunity to discuss
the NASA Engineering and Safety Center's independent assessment
of the F-22 life support system. I am honored to be serving as
the lead of this NESC team.
The NESC performs independent testing, analysis and
assessments to help address some of NASA's tougher challenges.
We can draw upon technical experts from all 10 NASA
centers, industry academia and other government agencies. This
allows us to bring the country's best experts to bear on
problems and challenges of NASA programs.
In April 2012, Major General Lyon requested NASA's
assistance in their efforts to determine the cause of the
hypoxia-like symptoms experienced by some F-22 pilots. NASA was
requested to review current post-incident protocols and
recommend enhanced procedures and also review the current
investigative process, ongoing root cause analysis and the F-22
life support system as a whole.
The NESC assembled a team that included two NASA flight
surgeons, two NASA human factor experts, an EPA [Environmental
Protection Agency] forensic chemist, an industry oxygen
generator system expert and several specialized NASA life
support systems engineers.
In the course of this investigation, the team reviewed data
from multiple sources, visited manufacturing sites and F-22
bases and held numerous discussions with knowledgeable
personnel. The NESC team's findings and recommendations are
based on this data and not on an exhaustive review of all F-22
documentation.
The NESC team concurs with the Air Force that the F-22
incidents can be attributed to several factors: One, the high
concentrations of oxygen at lower altitudes; two, the
inevitable acceleration which compounds the effects of high
oxygen; three, restricted breathing due to the inappropriate
inflation of the upper pressure garment; and four, contribution
of uncharacterized F-22 life support system vulnerabilities,
such as pressure drops [across] components in the cockpit.
The NESC team found a number of issues with the systems
providing breathing air to the pilot. These systems are often
treated as separate, but the events experienced are a result of
the complex interactions of these systems, which, with the
pilot included, are even more complex. Each flight puts extreme
physiological demands on the pilot. The F-22 pilot community
has come to consider a number of physiological phenomenon as a
normal part of flying the Raptor, such as the difficulty in
breathing and the Raptor cough. Acceptance of these phenomena
as normal could be seen as a normalization of deviance.
The NESC team found no evidence of a contaminant producing
a toxic exposure. However, in any jet fighter environment,
irritant compounds can be present. The F-22 has no effective
filtration of breathing air or cabin air, which means irritant
compounds could potentially enter the cockpit.
The team found that the investigative process could have
been more efficient. The F-22 task force was never given a
directive that assigned the authority to conduct the
investigation. They began with two narrow hypotheses and did
not communicate well to all parties.
The NESC team agrees with many of the Air Force's planned
corrective actions and has identified a number of other areas
for further consideration. These include both near- and long-
term recommendations. Many of the NESC near-term
recommendations are actively being addressed by the Air Force.
For example, the upper pressure garment and oxygen schedule are
currently being modified. Post-incident protocols to establish
standard case definitions and treatment guidance will require
some additional effort.
Longer-term recommendations include conducting end-to-end
testing of the life support system, environmental control
system and air crew flight equipment. We also recommend a
fundamental reassessment of the requirements for the life
support system in high-performance aircraft and a formal
lessons-learned review of the Air Force-led investigation.
In summary, the NESC team acknowledges that the F-22 Raptor
is a high-performance aircraft that is expanding the capability
of aircraft performance. The Air Force task force has made
great strides this summer in understanding the complex, highly
interrelated nature of this problem. The NESC's independent
analysis supports the Air Force plan of corrective actions.
Thank you, Mr. Chairman.
[The prepared statement of Mr. Cragg can be found in the
Appendix on page 99.]
Mr. Bartlett. Thank you all very much for your testimony.
Before we begin, I ask unanimous consent that
nonsubcommittee members, if any, be allowed to participate in
today's hearing after all subcommittee members have had an
opportunity to ask questions.
Is there an objection?
Without objection, nonsubcommittee members will be
recognized at the appropriate time for 5 minutes.
As is my usual custom in these hearings, I will reserve my
questions until the other subcommittee members have had an
opportunity to ask theirs.
Mr. Reyes.
Mr. Reyes. Thank you, Mr. Chairman.
Gentlemen, thank you for your testimony.
Let me start off this morning with the first question
dealing with what the long-term impact may be on pilots that
have flown the F-22. The testimony indicates that since pilots
have been flying the F-22 since 2005 with all the same
equipment that has now been identified as causing the oxygen
problems that we have discussed today and previously, over
time, this means that hundreds of pilots have flown the F-22.
So the questions I have are the following: What does the
Air Force know about any long-term health impacts from flying
the F-22? Second, has the Air Force gone back and examined the
health records of former pilots to perhaps look for clues on
the impact? And third, does the Air Force plan to continue to
research this issue and to track the health of current pilots?
So whoever wants to take those first three questions.
General Martin. Mr. Congressman, let me address that if I
could as the Air Force Scientific Advisory Board considered
those questions and in its recommendations presented the Air
Force with some thoughts about actions it should take.
First of all, with respect to the long-term effects of
flying the F-22, because the Scientific Advisory Board did not
conclude its work with root causes, it was not sure at that
point whether we had contamination getting into the breathing
air, which could have some sort of irritation or effect on the
pilot, or whether it was the interaction that General Lyon
discussed between the percentage of oxygen, the upper pressure
garment and breathing cycles associated with the work of
breathing.
But it had no knowledge of long-term effects by reviewing
pilots who had flown the aircraft before. It had no indications
that the phenomenon that they experienced in the airplane had
long-term effects. But nonetheless it, before returning to fly
in September of 2011, had a battery of physiological samples,
specimens taken from all of the pilots that would fly so that
had you a baseline record of those pilots, who, of course, had
not flown for 4 or 5 months, a baseline of their medical data,
and as recommended, the Air Force establish a medical registry
for all who fly the F-22 in case, as time goes on, there are
things that are discovered that we would want to be able to go
back and reference the conditions that may have changed within
those pilots.
But from the Scientific Advisory Board perspective, they
were unaware and were not able to find any long-term effects
for those people that they questioned but did establish a
medical baseline for those people who are currently flying the
F-22.
Mr. Reyes. Having said that, it is clear, at least from
just a layman's perspective of reading and listening to your
testimony, that individuals are affected differently by the
same. And I point out by way of example that according to some
of the testimony that I reviewed, that pilots were expected to
recover quickly. In some cases, the expectation was within
minutes or perhaps hours after flying and being affected by
this. But in reality, some plots took days to recover. So is
that--is that a cause of concern that we have one expectation
and the reality is completely different?
General Martin. I think it is safe to say that the
interaction that General Lyon discussed manifests itself in
different ways with different people. Particularly depending on
their breathing style and their blood saturation level,
hypoglycemia, things like that. But from the Air Force
Scientific Advisory Board perspective, since we did not know we
had not discounted the potential of contamination, we were not
led down the track of G atelectasis and other interactions that
General Lyon discussed as aggressively because we were pursuing
both hypotheses; one dealt with whether they are getting enough
air, and the other dealt with whether they are getting
contamination. And we had six sub-hypotheses for each of the
major two hypotheses that we were pursuing at the same time.
And I'll let General Lyon speak to this, but as they
continued the path of contamination and ultimately have stated
that it is unlikely that there's a contaminant problem with the
F-22 OBOGS system and focused more on the physiological effects
of high concentrations of oxygen, interference with the upper
pressure garment and perhaps some other physiological
considerations, that area is one that I think General Lyon
could address more completely than I.
Mr. Reyes. General.
General Lyon. Congressman Reyes, if I may, when we returned
to flying last September, General Martin's group gave us a
series of protocols to put in place, to take blood samples and
pulmonary function tests as a baseline for our Raptor pilots,
which has been very helpful for us to be able to determine once
they have had an incident, is there something which is resident
in their body, something which has a lingering effect? That was
mostly aimed at the potential contamination, of which we found
none. But I should step back a second and mention that everyone
who flies in an Air Force aircraft who is a rated officer goes
through a medical screening to be qualified for flight. And we
have annual physical health assessments that we go through that
recheck our pulmonary function, recheck our medical baselines
from urinalysis to blood samples, et cetera. Very rigorous. In
fact, every year, that's the day that pilots and aviators look
least forward to, is that trip to see the doctor, hoping they
still come out cleared to fly, as they do. We have a very
rigorous process for evaluating the health of our aviators.
What we have found is, with our pilots who operate in harsh
environments, whether it be high-G environment or high-altitude
environment, there are additional protocols that need to be in
place to understand the effects. High-G environments F-15s, F-
16s, F-22s, we learned in the 1980s that if pilots were not
properly trained, educated and equipped with anti-G protection,
they literally could knock themselves unconscious, and
tragically, we have lost many pilots to G loss of
consciousness. Years ago, the trend had increased significantly
with that training, education, and the equipment we gave them.
What we are finding is that with the maturing that we have
of the F-22 weapon system, we have been flying it operationally
since 2003, but a small number of aircraft, so the sorties, it
takes a while to get to numbers. What we are finding is this
reaction to the interaction between the equipment, the oxygen
delivery schedule, and we get this Raptor cough, what has been
referred to as Raptor cough. We can talk about that a bit more,
but those effects typically clear up within minutes, if not
hours, after flight. We have had a small number of pilots who
have had incidents that have had lingering effects that go out
to 48 to 72 hours. But within 72 hours, with treatment by our
aerospace medical professionals, those effects go away. All of
our pilots, all of our ground crew who have had incidents,
physiological incidents, have been returned to duty and fit for
flight status.
Mr. Reyes. And I have other questions, Mr. Chairman, but in
deference to the members that are here I will wait another
turn. But I did want to finish up by asking you, so your
position, your effective positions are that we do have a way to
go back and ensure that if something develops in the future for
these pilots, there can be a way to evaluate and analyze how it
might have been impacted by the F-22.
General Lyon. If I may, to close that out, one of General
Martin's recommendations was to establish a medical registry of
all F-22 pilots and associated ground crew. We have done that
with this baselining of their pulmonary tests and with their
blood tests.
What we have also learned from our friends at NASA, from
their expertise, is that there are other tests that we can put
in place, which will give us greater understanding and depth of
knowledge about pulmonary function. That is a recommendation
which has been given to me to incorporate into our findings as
we close out our analysis. Importantly, we know who has flown
the F-22. We know who has been exposed to this environment. We
have a registry of those people from the time that we have been
flying and will continue to track them through their Air Force
career and, if necessary, beyond.
We have a moral imperative, we understand that, that if
something is discovered that would be tied to this aircraft or
in servicing this aircraft, we have a moral imperative to take
care of those Americans.
Mr. Reyes. I thank the gentleman.
Mr. Chairman, I yield back.
Mr. Bartlett. Thank you. As per committee rules, members
present at gavel fall are recognized in the order of seniority
on the committee; those appearing after gavel fall, in the
order their appearance at the committee.
Ms. Hochul.
Ms. Hochul. Thank you, Mr. Chairman.
I would like to thank you for holding this important
hearing, first of all. I share the same view as everyone in
this room, that our pilots' safety has to be one of our highest
priorities. I know today we are primarily speaking about the F-
22 issue, and I have a closely related question. As we continue
to invest in the F-35 Joint Strike Fighter, a program I do
strongly support, is the Air Force aware of any problems or
potential problems that are looming similarly to what we are
experiencing with the F-22 with the F-35 program, is this
something we have been proactive about and anticipating?
General Martin. Ma'am, I would say the charter that we had
in the Air Force Scientific Advisory Board was to review other
military aircraft equipped with OBOGS systems and determine if
there were some lessons learned from those aircraft that we
could apply in the F-22 and, additionally, were there some
lessons from what we learned in the F-22 study that should
apply or could apply to those aircraft. With respect to the F-
35, it is an OBOGS system. It is manufactured by the same
manufacturer. It has a little different scheduling activity.
We have shared all of our information with the F-35 program
office, and I would say that their system was designed with a
bit more redundancy and robustness. It has a backup oxygen
system that is installed on the seat with a fairly large
quantity of air available to the pilot should the OBOG system
have a problem. And we know of no physiological incident that
has occurred in any of the F-35 flight operations to date,
through the flight test as well as some of the training
activities that are occurring down at Eglin.
So to your question with respect to the F-35, we did review
the system. It does have some differences, but it looks as if
those differences are refinements and improvements over what
the F-22 had, and we have shared the information that we
learned with the program office and, as well, with the Navy and
Marine Corps, who will be operating that airplane as well.
Ms. Hochul. That is all I have, Mr. Chairman.
I yield back the balance of my time. Thank you.
Mr. Bartlett. Mr. Runyan.
Mr. Runyan. Thank you, Mr. Chairman.
General Martin, I am sure there is a classified answer to
this, but specifically speaking to operating environment of the
F-22, what really differs between that and say the F-16, F-15,
F/A-18? What really sets it apart?
General Martin. Mr. Congressman, I will let General Lyon
discuss perhaps some of the warfighting characteristics of the
operational environment, but from a system design and human
systems integration perspective, the F-22, unlike all other
aircraft, can operate routinely and in a sustained manner above
50,000 feet. Typically, the Air Force has required its air
crews to use a full pressure suit when operating above 50,000
feet, even though the cabin pressurization is adequate and
safe. Should there be a rapid decompression at those altitudes,
the effect on the blood and the effect on your ability to
properly inspirate or breathe is very, very challenging without
supplemental pressure to keep your lungs from exploding and to
ensure that you are able to process the oxygen that is
delivered.
The F-22 does not have a full pressure suit, and it was
designed to operate with a partial pressure suit, the upper
pressure garment, a different anti-G suit and those sort of
things. So that airplane operates in an environment different
than what we had operated. For instance U-2s, SR-71s, those
airplanes, all of those air crew members fly in a full pressure
suit. The F-22 pilots do not, and therefore, it is important
they not only understand where they are vulnerable and the
limitations of the equipment but also the performance of the
equipment as they operate in those areas. So our concern was
making sure that not only did we have the right equipment and
that it would perform well and provide the protection that it
was intended to, but that the air crews would also know what
the differences were and how to operate in that environment.
So from a physiological perspective and from a design
perspective, that is the area of focus for the Air Force
Scientific Advisory Board.
With respect to the combat capability and advantages,
General Lyon I think can best address those for that
environment.
General Lyon. Congressman Runyan, I have over 3,000 hours
flying the F-16, and I can count the amount of time that I have
spent above 40,000 feet in less than 10 hours.
When I look at the operating envelope that our F-22 pilots
go into every day, every day, they go above 40,000 feet. They
operate at higher altitudes routinely than we have in the F-16
in the past and even than we did in the F-15. And they also
operate in a very high-G environment.
We have learned a lot over the last three decades about the
impacts of operating in a high-G environment with our fourth-
generation fighter legacy aircraft, and we have integrated
those efforts into the F-22. We still learn today, after half a
century of flying the U-2 at extremely high altitudes, we are
still learning how to care for those pilots and continuously
enhance their safety because of their exposure to very high
altitudes.
As General Martin mentioned, we have a partial pressure
suit in the F-22. It is a truly a hybrid aircraft that combines
high altitude and high G. And some of the equipment that we
found that we have is optimized for one of those environments
but not integrated to help with the other environment. That is
one of the key points that came out of our analysis over the
last year, is that we need to continue to do research on the
science, the physiology of both high altitude and high-G
flying, and the end-to-end integration and testing of all of
the components that have really one thing in mind. That is to
ensure that the proper volume of oxygen with the proper
concentration of oxygen gets to the pilot so he has full
cognitive skills and can handle the immense tasks that they
have in an environment that we have not flown routinely before.
Mr. Runyan. And I asked that question just to say we
understand that we can change the physiology of a machine, but
we can't change the physiology of a human being. We can push
the threshold with technology all day long. And I think this a
prime example of, we have spent a lot of money on developing
weapons and tactics that are outside the envelope, but we are
not going to be able to change the person that flies it. And I
think sometimes as we step back and look at things like this,
we really have to be cautious. I have the honor to actually sit
on the VA [Veterans' Affairs] Committee, and the list you speak
to, I don't want to really have to visit that--you know what I
mean--especially with the Raptor cough and all that kind of
stuff.
I would just say that technology is great, but at the end,
it is about the people. It is the men and women that do this
that we really have to look out for.
With that, Mr. Chairman, I yield back.
Mr. Bartlett. Thank you very much.
Ms. Speier.
Ms. Speier. Mr. Chairman and ranking member, I really
appreciate you holding this hearing. I am deeply concerned
about this issue. And I must say, I don't have the confidence
that we have come up with the answer yet.
Let me start by asking General Lyon, there was an article
that appeared today in the Dallas Star-Telegram, and I don't
know if you have seen it, but it suggests that the Air Force
knew about this back in 2000, that it declined a fix in 2005
that would have cost about $500,000 per aircraft. And that
alone I think deserves your response. So if you would, please
explain to the committee if you knew this back in 2000, if
there was a fix back in 2005 that you declined to incorporate
because of cost, which was at that time about $500,000.
General Lyon. Congresswoman Speier, I will be happy to
answer that question.
During the engineering and manufacturing development phase
of the F-22, we learned a lot. We had a lot of reports written
about the status of different aircraft systems, subsystems, and
how they interacted. And one of those reports was written in
2000 about the environmental condition system. Changes have
been made since then. Changes were made based on that report.
In 2005, when the report came out and suggesting yet a small
incremental change that you describe to this system, the
knowledge that we had at the time was that--the term Raptor
cough didn't even exist at that time. We didn't even know it.
We had some discussions about ear blocks, but we have
discussions about ear blocks in other aircraft that we fly as
well. So the determination in 2005 was what we knew about some
of these interactions, is that they were at a small level, not
widely spread, and we were still a very small fleet size at
that time.
It is as we have grown to the final delivery of our
aircraft and really expanded the people who fly and the numbers
of hours that they fly that we have gained a bigger
understanding of what is going on. And we continue to make
changes to this oxygen delivery schedule based on what we learn
along the way.
Ms. Speier. So the suggestion in 2005 has now been
incorporated or has not?
General Lyon. That suggestion has not been incorporated
specifically. It was a minor modification to the ECS
[environmental control system] system and the scheduling
performance. We are looking at broader changes than that and
making broader changes that envelop that one that was suggested
then.
Ms. Speier. But wasn't that suggestion to give the pilot
the opportunity to control the oxygen flow?
General Lyon. The pilot does. The pilot has a switch
setting in the aircraft, an automatic setting, which is a lower
oxygen concentration, and a maximum setting, which is a higher
oxygen concentration.
We have learned a lot about oxygen concentration. There was
a period of time when we thought we may not have been
delivering enough oxygen concentration. But what we have
learned over the last few years is that there are these cases
where the increased oxygen concentration does give some
dryness. It does give some ear block, and it does create this
Raptor cough, which is a temporary situation.
Ms. Speier. Thank you.
There has been some discussion about the fact that it is
not just the suit, that those on the ground are also
experiencing this condition, these hypoxia-like symptoms. Are
you confident that the epoxy that is used in adhering the skin
to the plane is not a contributing factor to this?
General Lyon. Congresswoman, I am confident. We have done
over 2,400 tests on the aircraft.
And if I may have the picture of the testing locations----
Ms. Speier. Excuse me, I am running out of time. You have
answered the question. Thank you.
Let me move on to ask you whether or not the reports that
you mentioned, one dating back to September, I guess, of last
year, if those are going to be made public so that the findings
and recommendations would be made available to the public?
General Martin. The Air Force Scientific Advisory Board
report has been completed. It has gone through its review,
several tiers of reviews, and will be released today. And the
findings and recommendations will be there.
If I could, ma'am, I would make a comment that you will see
in the report with respect to a better understanding of the
interaction of this aircraft with the human operating the
airplane, whether it be a maintenance technician or it be a
pilot.
In the 1990s, the United States Air Force, through its
manpower reductions and its prioritization of effort, brought
about by the downsizing of the military after Desert Storm, did
not continue with the robust effort it had for decades before,
its human systems integration, its aviation physiology.
Ms. Speier. And you relied on contractors, correct?
General Martin. Sorry?
Ms. Speier. You relied on contractors as opposed to----
General Martin. In many cases.
Flight medicine and aviation physiology research and
development atrophied significantly during those years. And at
a time when the airplane was going into a different environment
that we talked about earlier, the people that would normally
have done the testing and the evaluation and all of the things
that we do to learn about those new environments were no longer
in the military, no longer in our civilian workforce.
One of the recommendations is that the Air Force reenergize
its efforts with respect to human systems integration so that
we will better understand some of the interactions that we are
now learning about and actually, with the help of the Navy and
with NASA, know more about today than we did a year ago.
Ms. Speier. Thank you.
My time has expired.
Mr. Bartlett. Thank you very much.
I will ask a few questions, and then we will return, for
those who are interested, to a second round of questions.
I would just like to return for a moment to my opening
statement to make sure that a couple of statements there
weren't misunderstood. I read and concluded that either the
supply or the quality of the oxygen is contributing to F-22
pilots' hypoxia-like symptoms. I don't think those are the only
two possible reasons for these symptoms. I was simply reporting
what had been concluded. I didn't want this to be interpreted
as a statement of fact.
Next was the statement I made that the Air Combat Command
had determined that the root cause of the F-22 pilot
physiological issues is the supply of oxygen delivered to the
pilots, not the quality of oxygen delivered to the pilots. This
is what they concluded. I am not sure that is the correct
resolution of the problem. I just wanted to make sure that
people understood because I read those statements, I didn't
read them as statements of fact, I read them as an account of
what had been reported by the people who were investigating it.
I hardly know where to begin. I spent a big part of my life
in this area. And when I first came to work for the Navy as
school physiologist in Pensacola, Florida, a great many years
ago, they had just had an accident where the instructor and the
student had penetrated a 10,000-foot floor and for several
minutes were seen spiraling into the Pensacola sand. The
commanding officer felt that there was a problem with the
oxygen system. And since I was the physiologist, I was put on
the Accident Investigation Board and we spent a very long time,
as we appropriately do, looking at every aspect of this.
Let me ask a few questions.
The symptoms of hypocapnia, how early in your investigation
were you cognizant of the fact that it was difficult to
differentiate between hypocapnia and hypoxia? Hypocapnia is low
carbon dioxide. If you sit and breathe deeply a number of
breaths, if I sneeze three times, I have hypocapnia. I can feel
the difference. I am dizzy. How far along were you in your
investigation before you were cognizant of the fact that we
ought to be looking at the symptoms of hypocapnia as well as
the symptoms of hypoxia?
General Lyon. Thank you for the question, Chairman
Bartlett.
We started to learn over the winter that there were a
variety of symptoms that were emerging. And it was in April of
this year where we had our restricted breathing working group
that met, the combination of F-22 pilots and the professionals
across the medical field, where we really got into substantial
discussions about symptoms, as well as the research that had
been done with Duke University by Dr. Mitchum and with the
United States Navy, where we broadened our aperture and
understood that these symptoms, like light-headedness,
dizziness, fatigue, are actually ambiguous across things like
toxic exposure, hypoxia, hypocapnia, hypercapnia, hypoglycemia,
dehydration.
But I would say for me as the task force lead, the ``aha''
moment came in April, when we got that full team of experts
from different services, from NASA and from industry together.
That is where it really started to emerge in our mind.
Mr. Bartlett. How difficult is it to differentiate between
the symptoms of hypoxia and hypocapnia?
General Lyon. Chairman Bartlett, I tread on dangerous
ground now engaging in a discussion with you with your level of
knowledge about this. But what I have learned as the task force
lead as I talk to professionals about this is that many of
these symptoms are temporary. They emerge, and then they
disappear. And it is hard to find any kind of DNA
[Deoxyribonucleic Acid] trace that goes along with this. In
fact, our protocols that have we put in place did not show any
of these. So they are very temporary, and they come and go. So
that has been one of the challenges.
The other thing that they have told me is there is an
individual variability factor here as well, that every human is
a dependent variable if we think of this in terms of a test.
And not only that, but from day to day, a human being is going
to interact differently depending on how much sleep they had.
Are they well rested? Are they hydrated? What are their blood
sugar levels?
So this understanding of the physiology and the science not
only for, as Congressman Runyan was alluding to about the high
altitudes and pushing the envelope, but just the basic
physiology where we have let some of these skill set atrophy
over the years as we downsized our Air Force during the post-
Cold War period, that we were relearning old lessons. But in
April, that is where it all came back to me.
Mr. Bartlett. Is it not true that, in large measure, the
symptoms of hypoxia and the symptoms of hypocapnia are
indistinguishable?
General Lyon. Mr. Chairman, in fact, that is what I found.
I have to put things in fairly simple terms, and I asked them
to give me a chart listing all of these different cases,
hypocapnia, hypercapnia, et cetera, and then listing what are
the symptoms. It looks almost like a complete ladder of Xs from
left to right all filled in. They are almost a one-for-one
match of symptoms across all of these various symptoms that we
talked about in these causes.
Mr. Bartlett. We have a very interesting dynamic here. If
you think that you are hypoxic, the normal response to that is
to try and get more oxygen. That is what you need, so you
breathe deeper and maybe faster. And you can do that, and you
will not be aware of the fact that you are breathing deeper and
faster. And when you do that, you now drive down CO2 [carbon
dioxide], and you create the symptoms of the thing that you
were trying to avoid, that is hypoxia, because as you drive
down the carbon dioxide concentration in your body, you have
essentially exactly the same symptoms that you would have if
you had a low oxygen concentration in your body. So now you
begin a vicious cycle. I feel worse. I need to breathe deeper.
You don't say that to yourself, but that is the physiological
response to that. So now you breathe deeper. And the deeper and
faster you breathe, the worse you feel. So you are kind of on a
vicious cycle here.
What partial pressure of oxygen do you try to maintain in
the breathing mixture? I am going to ask a question, too, about
Raptor cough and try to make sure that people understand where
that comes from, that this isn't something evil and it is just
a natural consequence of doing what you do in flying these
aircraft. This is what happens.
General Lyon. Mr. Chairman, we mean well above the useful
consciousness requirement for----
Mr. Bartlett. We are roughly at sea level here. I think it
is about 158, the partial pressure. And in our lungs it is
diluted by CO2 and so forth, and it is down to about 100
millimeters of mercury.
General Lyon. Yes, sir.
Mr. Bartlett. Do we try to maintain the concentration of
oxygen significantly above 158 millimeters of mercury?
General Lyon. Significantly above it, in fact. We are
approaching 90 percent, 80-90 percent pure oxygen at the higher
altitudes that we fly.
Mr. Bartlett. What happens when you have a very high
percentage of oxygen in your lungs is if that oxygen is picked
up by the capillaries in the lungs, there is nothing then--the
nitrogen is gone. You have eliminated that by increasing the
oxygen percentage. Ordinarily here, we have about 80 percent
nitrogen. It just stays in there and holds the alveoli open.
What you end up with is a situation like if you take two pieces
of wet paper and put them together, you have to tug at them to
get them apart. That is the surface tension of water. That is
what happens when you have a very high oxygen concentration.
You increase the probability--and I noted you were recommending
that they go to max oxygen--you now increase the probability of
atelectasis because you are driving down the concentration of
nitrogen, so you increase the incidence of atelectasis. And
that is an irritation, and you cough to try to open those
alveoli up, and it could take quite a while to open the alveoli
up, which is why it may persist for awhile.
You all have done an admirable job of pursuing this. All of
these instances occurred at two of your eight bases, is that
true?
General Lyon. Mr. Chairman, we have six permanent operating
bases.
Mr. Bartlett. And at how many of those did this occur?
General Lyon. And your eight is correct. We have two
forward present bases.
Mr. Bartlett. So eight total. And it occurred in only two.
General Lyon. Only two.
Mr. Bartlett. Which is another indication that what is
happening here is not a problem with--and this is a very
complex relationship between the pilot and his system. Pilots
are taught early on that they can't really trust their senses.
You have cockpit signals that tell you what is up and what is
down, and you have learned to trust those rather than the seat
of your pants, because you really can't trust that. And all of
you have been, I gather, how many times do you go in that
altitude chamber and they ask you to take off your mask? And
you take off your mask, and you are doing something like
writing something, and you think you are doing just fine. And
then you put your mask back on, and you look at what you have
done, and wow, how could I have done that? There is little
perception that you are becoming hypoxic. And you think that
you are doing just great, and the better you feel you are
doing, the worse you are doing. So the pilots have learned that
they can't really trust their senses. They have got to trust
other things.
I am really pleased that you put two things in this system
that now pilots can look to. One is an oximeter on the ear now,
I gather, that tells you what your oxygenation is in your
blood. If that is up, you have got enough oxygen. No matter how
you feel about it, you have got enough oxygen if that is up. I
think you also put a sensor in that tells them what the percent
oxygen is in their delivery system?
General Lyon. Yes, Mr. Chairman.
Mr. Bartlett. There needs to be a protocol that keeps that
as near 158 as you can. If you run it much above that, you are
going to increase the incidence of atelectasis. And this kind
of breeds some perception that there is a problem with the
airplane or a problem with the oxygen system or something if
you have atelectasis. It is not a problem with either, it is
just a fact that if you are breathing a high percentage of
oxygen and pulling Gs, which is going to exacerbate the thing,
that you are going to have more atelectasis.
Well, I have asked enough questions for the moment.
Let me turn to Mr. Reyes for his questions. And we'll come
back.
Mr. Reyes. Thank you, Mr. Chairman.
Listening to the chairman, I was wondering, you know, we
first deployed the F-22 in 2005, and it wasn't up until 2008 or
so that these problems started to surface, so I am wondering
what explanation is there for this time lag? Were the problems
there all along and just not being reported, or did you change
the operational, you know, operational capability--not
capability but the operational environment of the F-22 that
brought upon the pilots this problem?
General Lyon. Thank you for that question, Congressman
Reyes.
After a few years of operational flying, we started to get
a large number of aircraft, a larger population. We get into
the individual variability of the pilots who were flying. And
in 2008, we had several incidents.
One of the things that was informative to me from Mr.
Cragg's independent analysis was this thing known as the
normalization of deviance, which was learned from their studies
that they have done on some of their safety and engineering
studies for things which have occurred with NASA in the past.
There was an acceptance early on by the Raptor pilots who
flew this aircraft that it is a littler harder to breathe than
it is in other aircraft. And they were taught that it is a
little harder to breathe, and they began to accept it. But over
time, as the pool of pilots got larger and we flew more, we
started to see some of this individual variability come into
play. And then we had some incidents, and we really started
focusing on it.
What was also helpful for me as I worked through this
analysis was looking at the Air Force's history in another
aircraft, the F-16. The F-16 flew operationally for 4 years
before it had the first G loss of consciousness [G-LOC]. Same
capabilities in the aircraft; same G available, the same
qualification and criteria to get into the aircraft. But we
flew for 4 years. And I asked myself, why? I still don't have
an answer as to why it took 4 years for G loss of consciousness
to become an issue and then continue on for awhile. But it is
not uncommon from what I have seen in some case studies to fly
aircraft for a number of years, very selective pilots and
aviators at the very beginning part, very controlled
environments, but we start to broaden the aperture and bring
more folks in, and we start to see more variability over time.
Mr. Reyes. The other question that comes to my mind is we
are dealing with the F-22 in this hearing, but are there
lessons to be learned as we transition to the F-35? Does the F-
35--do we anticipate that it is going to have similar issues,
or the fact that we are working our way through finding
solutions for the F-22, is that going to be beneficial for the
F-35?
General Martin. Congressman Reyes, I would say this, that
the F-35 oxygen system is more robust than the F-22 in terms of
its design and redundancy. The formula that it uses for
computing the percentage of oxygen is slightly different. And
from the lessons we have learned with respect to connections,
potential for leakage, and of course the emergency oxygen
system, they have applied those lessons in the F-35.
As General Lyon has indicated, that will not stop all
potential hypoxia-like incidents or hypoxia incidents due to
hyperventilation or other things that could occur. But in terms
of the design, it seems as if the F-35 has gone to school on
the F-22. And of course, both with what General Lyon's team has
done and with what the AFSAB did, we have shared all of that
information. In fact, during the early part of our study,
NAVAIR systems people were fully integrated into our effort and
shared with us the lessons they had learned in OBOGS in general
and where they were with the F-35.
So we are doing our best to make sure what we have learned
here will apply to the training and to the design and operation
of the F-35.
Mr. Reyes. Thank you.
And I have some other questions, but I will submit them for
the record.
Mr. Bartlett. Thank you.
Ms. Speier.
Ms. Speier. Thank you, Mr. Chairman.
Mr. Cragg, I was particularly struck by the statement in
your report that reads, the acceptance of these phenomena as,
quote, normal could be seen as, quote, normalization of
deviance, that the F-22 has no effective filtration of
breathing air or cabin air and although no conclusive evidence
has been found indicating the effect of irritant compounds,
they could enter the cockpit and the pilot's breathing air
supply.
Could you comment a little more on those statements,
please?
Mr. Cragg. Sure. Thanks for the question.
NASA is very familiar with the term ``normalization of
deviance.'' It is when we get to a position where we accept the
operation of some system or component that is not operating
properly, and we start treating it as that is the way it
normally is. And the best example from NASA's perspective was
the foam coming off the external tank for the shuttle. It
happened since the beginning, and we came to accept it as a
normal part of doing business, but it wasn't. And we should
have fixed it long before.
So when we began examining the F-22, things like the Raptor
cough, things like the pilots going home at night being
physically exhausted, said to us, there is something that may
fit into this category of normalization of deviance. So we
wanted to point that out. It is a way that you can almost fall
into that type of a mind set if everybody says it is normal,
and especially with the F-22 being the top of the line Air
Force fighter, when people say, do you want to fly this
fighter? Yes, yes, of course, I do. There are some things that
are different about this; it is harder to breathe, but the
pilots just apparently didn't care. They wanted to jump in and
begin flying it.
So the normalization of deviance is a cultural thing that I
think the Air Force needs to take a look at and help prevent
from occurring in the future.
Ms. Speier. And your reference to this filtration system
and the fact that these toxic compounds can get into the oxygen
system, could you comment on that?
Mr. Cragg. We began our review by trying to double-check
some of the things that we understood that the Air Force had
already done. One of the things they looked at quite
extensively was the contamination issue. So I had my people
examine all of the evidence, the data, and we came up with a
conclusion that we found no contaminants that were getting into
either the breathing supply or the cockpit that would cause a
toxic condition for the pilot.
Having said that, during that examination, we found that
the air coming into the cockpit and the breathing supply is not
filtered. And so, it is not filtered, which would put the pilot
in a position where he is breathing air like in any jet fighter
environment. There are irritant compounds. There is potentially
some exhaust gases that the individual may be breathing. We
wanted to highlight the fact that the onboard oxygen generator
is not a great filter. It is filtering a lot. Some of the cabin
air that is coming into the cabin is being filtered by what is
called coalescer socks. But we wanted just to point out that
the air coming in is not completely pristine.
Ms. Speier. Are you suggesting that it should be completely
filtered?
Mr. Cragg. No. No. Ultimately what we are suggesting is
that some of these irritant compounds could potentially cause a
pulmonary problem or a restriction of breathing. One of the
members of my team is from the EPA, who has done testing with
irritant compounds and has found that to be the case in some
individuals. It is highly an individual response to that.
Ms. Speier. Two more questions I want to try to get in in
42 seconds here.
The Air Force has said that none of the hypoxia incidents
have resulted in long-term or lingering physiological effects.
But a medical expert wrote in Flying Safety Magazine that a
pilot who experienced these symptoms was restricted from flying
for several days. Wives of pilots have also described what they
believe to be long-term or lingering effects, and many of these
pilots describe blackouts and memory loss when they experience
symptoms. Some pilots also describe experiences of vertigo
weeks later. To what degree do you think that we need to look
at biomarkers as part of this evaluation?
Mr. Cragg. I think that is a very good question. I had two
NASA flight surgeons on my team, and they did some extensive
review of what the Air Force has done. I would not like to
speak for them. I wanted to make sure what we put in our report
as far as the medical portion was exactly correct, so I ensured
that that portion of our report was thoroughly peer-reviewed by
other flight surgeons. So if you don't mind, ma'am, I will take
that one for the record, and I will provide you an answer.
[The information referred to can be found in the Appendix
on page 105.]
Ms. Speier. I appreciate that. One last question.
Have any of the pilots declined to fly the F-22 because of
what has transpired?
General Lyon. We have one pilot across the entire F-22
enterprise who is currently not on flying status based on his
request.
Ms. Speier. Thank you.
Mr. Bartlett. Thank you very much.
Mr. Reyes mentioned G-LOC; this is the unconsciousness you
get when you are pulling Gs. And this is due to an apparent
design defect in us. Essentially, every other part of our body
has the ability to accumulate an oxygen debt, which is why you
keep breathing, huffing and puffing, after you run hard. Our
brain has zero ability to accumulate an oxygen debt. So the
moment it doesn't have enough oxygen to operate, it just quits
operating. And we try to avoid this, of course.
When you are pulling Gs, the blood, by centrifugal force,
it is taken down to your legs and abdomen. And we try to avoid
this by anti-G suits, something that as soon as you start
pulling Gs, they start squeezing on your abdomen and your legs
to make sure that the blood can't pool there. But you can't
always do enough of that, and sometimes the blood still may
pool there enough that you get some transience. I have no idea
why there is that design defect. You would think that ought to
be built in. If anything needs to work all of the time, it is
the brain, isn't it? But if it doesn't have enough oxygen, it
just quits.
Ms. Speier mentioned vertigo weeks later. I was just
thinking, unless there is some pollutant in the oxygen, and I
think you pretty much ruled that out with all of your testing,
there is just nothing that can happen during flight, hypoxia or
hyperventilation, that is going to--you might better look to
what he did last night than look at the hypoxia or the
hypocapnia that he experienced 6 weeks earlier.
I have a series of questions that we would like to get
answers to.
Let me ask you, first of all, is there any evidence, other
than circumstantial, that there was ever an hypoxic incident?
General Lyon. Mr. Chairman, if I may lead and then if
General Martin would like to add.
One of the things that we found is that early on, the
discussion centered on hypoxia, and then the discussion became
hypoxia-like. But in the end, what our analysis said is these
are physiological events, which get back to the things that we
described a little earlier today that get into physiology.
Physiological events is the umbrella, of which hypoxia is one
of the parts of that. But most of these events are so
ambiguous, and these multiple factors, that we didn't have the
science early on when we had these incidents to really plumb to
the depth required to determine hypoxia from exposure to
compounds to hypoglycemia, et cetera.
It is only through the protocols and the learning that came
out of General Martin's efforts that we have been able to
understand these incidents in more depth over the last year,
that have allowed us to rule out things like contamination as a
root cause for what was happening to our pilots. And we start
to see that it is these breathing restrictions and breathing
impedances, as you referred to, which can lead to hypercapnia
or hypocapnia or similar type events for restricted breathing.
But that is where I end the analysis with my conclusions,
after I have taken all of the findings that have come in from
the other bodies and looked at this in total. They are not
hypoxia, per se. A small number of them are hypoxia.
We have had some pilots who have had interruptions in their
pilot supplies, and we have tracked that, and we have noted
that. So we do know that if there was an interruption, a
malfunction, that they will get less air and they will, indeed,
become hypoxic. But most of what we have been studying, what we
have been concerned about, are the instances where there was no
explanation at the time, and they do not lead you to hypoxia.
General Martin. During our review of the cases and after we
initiated the return to fly phase, where we had the finger
pulse oximeter, there were--we had data that seemed to
correlate with the symptoms and the physiological presentation
of what you would call hypoxia. For instance, a pilot cruising
out through 15,000 feet began to sense his hypoxia symptoms,
began to feel somewhat light-headed, looked at his pulse
oximeter and saw that it was at 85 percent or 83 percent. As we
went further into the data review over a period of months and
gathered more data and became much more conversant with the
strength and weaknesses of a tool such as that, we found that
oftentimes what seemed to be a correlation turned out to be
what the medical world refers to as artifact data or data that
was not accurate. And we did not know at that time that perhaps
the best indicator of whether the oximeter was working properly
or not was the pulse. And if the pulse went away, then the
oxygen dosage or the oxygenation number may not be accurate.
So we thought we had some fairly representative samples of
someone not getting the oxygen that they needed to perform
without impairment and their symptoms. And it turned out that
in almost every case, that data was inaccurate. Hence, the
pulse oximeter that will go in the head because the extremity
is the last place that the body is going to push the blood when
necessary to preserve function of the brain and the core of the
body. So we should get better data with this, but still there
will be some artifact data just based on the technology used to
measure.
I have no doubt that some of the cases that we reviewed,
that the pilot believed that he was suffering from hypoxia; but
it may not have been hypoxia, it may have been the symptoms
that were similar. And those are the symptoms that he or she
felt in the physiological training unit. And when they went to
high altitude, and one of the cases that you mentioned, not
only do we do some exercises, but we are supposed to mark, if
you will, perhaps a narrowing of the vision, perhaps a loss of
color, perhaps a dizziness, perhaps a light-headedness, perhaps
other symptoms. We are supposed to note that so if we felt that
in the aircraft, then we would immediately go to 100 percent
oxygen and recover the aircraft.
I have no doubt that there were air crew members or pilots
who experienced those same symptoms, but we can't prove that it
was due to a lack of oxygen from the OBOGS system itself.
Mr. Bartlett. Are we now acquainting our pilots with the
similarity and the symptoms between hypocapnia and hypoxia?
General Lyon. Mr. Chairman, indeed, we are. In fact, we
have visited five of the six permanent location sites. The one
location they are deployed currently, so we haven't been out to
see them. But we have pushed them the information.
Where we have shown them the results of the centrifuge and
altitude chamber training, that was my next ``aha'' moment in
about the May-June timeframe, where we, for the first time, put
F-22 pilots, wearing their F-22 flying ensemble, into ground
testing and altitude chambers and centrifuges, and we measured
that the system was not performing the way we thought it had
been performing over years.
We have advanced the state of testing and our ability to
understand what the oxygen delivery is. We have shown the
results of that to the pilots. In fact, 2 of the first 12
pilots who did centrifuge testing replicated their hypoxia
symptoms on the ground in a centrifuge inside a closed
building. That was an ``aha'' moment for me that really started
to point toward one of the factors. As you rightly pointed out,
Mr. Chairman, it is more than one factor. But one of the
factors is this restriction in breathing or impedance in
breathing, which can come--the restriction from the upper
pressure garment, and the impedance from the C2A1 filter, which
we have been flying with for a period of time to protect
against the possibility of contaminants, and also the pressure
drops that the Navy helped us with, in understanding it and
NASA affirmed it. The pressure drops that occur inside the
cockpit as the air flows through the oxygen hoses and the quick
connects; we had measurable, objective data, and we have shown
it to our pilots. And they are aware of that.
We have not had an incident since the 8th of March this
year, over 6 months ago. This is longest period without a
physiological unexplained incident in years.
Mr. Bartlett. Did you have an increased incidence of these
events when you had the filter in?
General Lyon. Mr. Chairman, we did. When we returned to fly
September of last year, we put a number of measures in place to
protect our pilots, to ensure their safety, to enhance their
safety. And some of these things we put in place actually
increased the incidence. One of the measures that we put in
place was guidance from me to the entire F-22 fleet that said,
at the first sign, the first symptom of anything, you are
directed to terminate your mission and come home. We injected a
sensitivity because safety was paramount in our mind. And they
responded to that. And they did safely recover every aircraft
each time that we had an incident.
But I marked my guidance as the Air Combat Command Director
of Operations with their safety as paramount, to come home and
terminate it, that we have injected an increase in the incident
rate during that timeframe.
Mr. Bartlett. Yeah. I would have predicted an increase in
the reported incidents if you put a noticeable resistance in
the line because the response to that is, gee, it is hard to
breathe; I am not getting enough oxygen; I need to breathe
deeper. So when you do that, you create hypocapnia, and you
create the symptoms of the things that you are trying to avoid,
don't you?
General Lyon. Mr. Chairman, you are exactly right.
And to also dovetail off of what Mr. Cragg has said, when
we put this canister on pilots and told them to fly with it to
protect them in the event of contamination, what we failed to
tell them was this known breathing impedance. We knew about the
breathing impedance. What we didn't know was about the
restriction in breathing that came with the upper pressure
garment. And the combination of the restriction from the upper
pressure garment plus this impedance we believe is what in this
individual variability sent a number of our pilots beyond their
normal physiological limits to where they saw these first
symptoms.
Mr. Bartlett. Let me quickly go through some questions that
the staff wants to make sure we have on the record so there is
no misunderstanding in the general public about the intensity
of our effort to solve this problem. You don't need to give a
full answer here. You may give a more complete answer for the
record, if you wish.
In your findings, you cite a number of failures in F-22
modeling and simulation of the F-22 life support system. Do you
believe engine-to-mask modeling and simulation, dynamic
response testing across the full range of simulated
environments, statistical analysis for analyzing and predicting
system performance and risk, and OBOGS performance when
presented with a full range of ECS air contaminants should be
accomplished for the F-22 program?
I guess a simple yes or no is okay.
General Martin. Yes.
Mr. Bartlett. What causes what has become known as the
Raptor cough? How frequently is it experienced by the average
F-22 pilot, and how serious an experience is it for the pilot?
Does the Raptor cough have any long-term effect on the pilots?
Do you think the record needs any more than what we have
discussed?
General Lyon. Individual variability, there is no standard
number of events. Some individuals don't have it at all. Some
have it more than others. And we have no indication of long-
term effect.
Mr. Bartlett. You will reduce those incidents if you keep
oxygen as low as is feasible, right. The blood is oxygenated
not because you push a lot of oxygen pressure into it, because
it has got hemoglobin, which carries blood. The amount of
oxygen that is carried in the blood by solution in the blood is
very small. So any time you get over 158 millimeters of mercury
partial pressure, you are minisculely increasing the amount of
oxygen available to the tissue, but you are considerably
increasing the probability of atelectasis.
Is there any linkage between hyperventilation and the
Raptor cough? I was trying to think of--can you increase the
Raptor cough atelectasis by hyperventilation?
General Lyon. We have not made that linkage yet. Although
what we have mentioned is one of the institutional things that
we will continue to work on is further study of this man-
machine interface, not only for the F-22 but for other
aircraft. Atelectasis and the Raptor cough, there is
relationship between the two.
Mr. Bartlett. Of course. That is why you have the cough.
How thoroughly did your study group examine this issue, and
does your report draw any conclusions or make any
recommendations to address the Raptor cough issue? Is there any
modification to the F-22 oxygen system that would minimize or
eliminate the Raptor cough and its effect?
I will answer my own question. If you keep the CO--or the
oxygen level as close as you can to 158 millimeters of mercury,
where your blood will be adequately oxygenated, you will reduce
the incidences, I think.
As you fill the lungs with more and more oxygen and less
and less nitrogen is there to hold the alveoli open, you are
going to increase the incidence of that; am I correct?
General Lyon. Yes, Mr. Chairman.
May I add one thing for the record, one of the reasons we
are significantly above 158 is for protection against the
possibility, however slight, but the possibility of rapid
decompression at high altitudes. As you know, super-oxygenating
the bloodstream will maximize our time of useful consciousness,
should we have that take place.
Mr. Bartlett. There is a press report this morning
indicating that the Air Force medical experts linked the Raptor
cough to the F-22's air supply system. I would hope so. The
article indicates that the Air Force decided in 2005 not to
make a fix to the F-22 oxygen system. Do you know if a
modification to the F-22 air supply system was considered in
2005 to address the Raptor cough issue and why the modification
was not made?
General Martin. Sir, let me give you a partial answer here.
First of all, the bleed air satisfies many customers. It
satisfies the cooling requirements for the flight control
computer. It satisfies the communication navigation cooling
system. It satisfies the fire control system. It provides
pressurization to the cabin. And it also provides the
pressurized air at a specific pressure and temperature to
OBOGS, which then delivers breathing air to the pilot. It is
controlled by a node, known as the air cycle machine, which
meters the amount of air necessary to the customers, based on
the pressurized air coming in as well as the temperature. If
the temperature begins to creep up, which at high-altitude,
low-power settings, it does, it then begins to shut down the
delivery of the air to some of those customers down range, and
the OBOGS is one of them. At that point, then, there is a
restriction to the amount of air the pilot might get, to
include zero, when the OBOGS has no pressure at the front.
We knew that in the early testing, and there were
modifications to the air cycle machine's algorithms that
controlled the metering of the air, and that, again, was
brought forward in the 2005 timeframe as a part of the
discussion there.
As a result of the SAB study, the program office has gone
back into that algorithm and adjusted it again, because the
number of ECS rollbacks or shutdowns was greater than predicted
or expected, and they have tried to adjust that air cycle
machine mechanism to reduce the number of shutdowns that would
occur, therefore, shutting off the oxygen to the pilot.
Further, as you know, from what General Lyon said, there
will be a backup oxygen system placed on the aircraft so that
if that happens, you will still get breathable air from the
backup system that will be much larger than the basic emergency
activation system we have today.
Mr. Bartlett. In early designs of the F-22, didn't we have
a backup system, and wasn't it taken out to reduce cost?
General Martin. It was not a cost issue, sir. It is true
that it was taken out. It did have an initial design of a
backup oxygen in addition to the emergency oxygen system. A
series of events occurred, but the catalyst for this particular
decision was the term that every aircraft goes through, the war
on weight.
After the prototypes had flown, they then begin to go into
their engineering, manufacturing, development phase. And at
that point, you begin to find out where the strengths and
weaknesses are. The aircraft always gain weight. When it gains
weight, it may not be able to pass its key performance
parameters of sustained G or acceleration or altitude or
whatever. So, at that point, they had to get the weight down.
The difficulty here was that as we went into acquisition
reform, we created the IPT [Integrated Product Team] structure,
and at that point, very tough decisions were made in terms of
who had the authority to make certain decisions. That usually
was generated as a result of a very conscientious review to
determine where your safety-of-flight critical items were. And
as the program evolved, the backup oxygen system, the OBOGS and
the emergency oxygen system were not considered safety-of-
flight critical. They were safety significant, which meant that
the decision to take the backup oxygen system off could be made
at a lower level than the chief engineer of the F-22, and it
was. And it was not known at that time by the senior leadership
that that--the analysis that went into that trade study that
allowed the backup oxygen system to come off.
In retrospect, that was not an appropriate decision. But at
that time, that is what the decision was. Now that decision was
made also with the information that the environmental control
system, ECS, IPT was going to put a shunt valve in that would
always ensure there would be positive pressure to the OBOGS,
and therefore, taking the backup system off would not be a
problem, given that you had an emergency backup system should
the OBOGS fail entirely.
So what looks like what I would consider to be a flippant
decision turned out to be steeped in data and very well thought
out, but it was perhaps not viewed by the more experienced and
senior engineer responsible for the F-22.
Mr. Bartlett. If weight is that critical, what do we prune
now so we can put it back in?
General Martin. Sir, first of all, it was 15.4 pounds, as I
recall. And they were looking for every pound they could find.
The performance of the aircraft is so magnificent that 15
pounds is not going to hurt this aircraft.
Mr. Bartlett. Is there any explanation of why the reported
hypoxia incidents have been concentrated at only two of the six
operating bases?
General Lyon. We asked the Air Force Safety Center, Mr.
Chairman, to go to all of the F-22 bases and talk to the crews,
the air crew and the ground crew, to help us understand some of
the factors beyond what I would call hard science, beyond
engineering science, and get into the human factors.
One of the locations is Joint Base Elmendorf-Richardson,
where tragically, in November 2010, Captain Jeff Haney lost his
life. And there was a cluster of incidents that took place in
May 2011, just before the standdown occurred. There is a
residual effect within the community that occurs when you
suffer through a tragedy. And as General Martin mentioned
earlier today, there was a period of quite some time, nearly a
year, uncertainty about what caused Captain Haney's crash and
the loss of his life. So this built up and manifest inside the
community, and there is residual effect that has come from
that.
At the other base, Joint Base Langley-Eustis, we found that
there was a set of factors there where the C2A1 canister--and I
can tell you from my discussions with all of the wings, the
C2A1 canister had a different meaning at that installation than
it did at the other five. And we saw several clusters take
place. And the human factors engineers and scientists tell us
that this is to be expected, that if there is a perception of a
problem, and somebody credible within the organization has a
problem, others will begin to experience the same thing. And
that is what we had; credible aviators who had a perception
that we had helped them believe, there is a problem with your
life support system which could have been contamination, and at
the first sign, saying, I have a problem, terminating the
mission. Their credibility extended to other people at their
installation. That is how we explain it.
At the other installations, they never got to that point.
But there were factors resident localized that had
professionals make well-measured, good decisions to terminate
missions because they had the perception that there was a
problem.
General Martin. One other comment, Mr. Chairman.
When the Scientific Advisory Board recommended the return-
to-fly protocols and the steps to be taken, it knew or it
believed that it would be important for us to continue the
return-to-fly process until at least March of 2012, because
that would give us a fairly representative sample across the
fleet of the different seasons. It also turns out that at
Elmendorf and at Langley, those two bases fly with the
protective gear for winter operations, which means if you
haven't readjusted your upper pressure garment and you now fly
with more stuff, the restriction to the breathing could be
greater. And the incidents may very well have also been related
to the fact that we didn't have a proper standard for the upper
pressure garment fitting, and then we didn't change the upper
pressure garment fitting when we put on the rubberized and
cold-weather gear.
Mr. Bartlett. Thank you.
General Lyon, I think you probably have articulated the
major reason for this. A little anecdote may help put that in
perspective.
If you are provided a breathing mask and you are sat behind
a screen and you are getting your air supply through a tube and
you are told that, by and by, you will smell violets and you
are supposed to indicate to the investigator when you smell
violets, essentially everybody will smell violets. The
investigator has not done one thing to the air supply.
These are very subjective things, and it is kind of tough
for us to recognize that we are not in full control of these
things. But these are very subjective things. And if you think
that there is going to be a problem with your oxygen supply
system and you may become hypoxic, the least little thing will
trigger this hyperventilation, unperceptible to the pilot, and
he will then have exactly the symptoms of the thing that he
dreaded, and that is hypoxia. It is a very interesting thing
that has happened here, and I am sure that this was a learning
experience for everybody who was involved in the investigation.
Is there an explanation--why do you believe that the pilots
have not previously complained until recently about the chest
constriction caused by the upper pressure garment now
determined to be a causal factor in the F-22 physiological
problems?
I am not sure, my statement seems to imply it was a causal
factor.
Do you think there is any causal factor other than the fact
that the perception was, gee, my breathing is impeded a little
and I guess I need to breathe more to get oxygen. And so they
end up breathing more and get hypocapnia, which are exactly the
symptoms of hypoxia? Is there another explanation?
General Lyon. If I have the question correctly, and I am
not sure I do, Mr. Chairman, how did they go for so long with
this upper pressure garment filling prematurely, restricting
their breathing and not knowing it, this is--what helped inform
us was the normalization of deviance that Mr. Cragg has
mentioned.
When we put these F-22 pilots into the centrifuge with
their gear on and they were accelerated to high G, we measured
the fact that they were prematurely filling and restricting
their breathing, and then we were able to measure, if we could
have the chart that shows--as you can see on the chart in front
you, Mr. Chairman, that without the upper pressure garment on,
the tall blue spike shows how quickly they can inspire and get
the required volume and that the red line shows that with the
upper pressure garment on, they cannot get the depth that they
need, and it takes longer to breathe. And as you already
mentioned, Mr. Chairman, the brain just does this without the
pilot knowing perceptibly that he is changing his breathing.
This is what we have come to know, which the Navy helped us
with, this understanding of the work of breathing. Breathing
restrictions integrated into the pilot's flight ensemble,
forced them to work harder to get the required volumes of air,
which can then lead to fatigue symptoms over time.
Mr. Bartlett. When I got my doctorate and its emphasis was
in this subject 60 years ago, I never dreamed that I would be
sitting here at a subcommittee hearing where this information
would be relevant.
Do all other fighter aircraft have a backup oxygen system?
General Martin. Could you repeat that question, sir?
Mr. Bartlett. Do all other fighter aircraft have a backup
oxygen system?
General Martin. Sir, they all have an emergency oxygen
system, and they either have a backup oxygen system, or they
have a plenum, which is like a reservoir that gives them
additional air should the OBOGS system fail.
Mr. Bartlett. Thank you very much for staying here through
a very long subcommittee hearing. I hope that this puts at ease
the minds of our pilots and their families. Thank you for doing
a great job of investigating this, and thank you for your
testimony today.
[Whereupon, at 12:00 p.m., the subcommittee was adjourned.]
=======================================================================
A P P E N D I X
September 13, 2012
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PREPARED STATEMENTS SUBMITTED FOR THE RECORD
September 13, 2012
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[GRAPHIC(S) NOT AVAILABLE IN TIFF FORMAT]
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WITNESS RESPONSES TO QUESTIONS ASKED DURING
THE HEARING
September 13, 2012
=======================================================================
RESPONSE TO QUESTIONS SUBMITTED BY MS. SPEIER
Mr. Cragg. The NESC Team report has described recommended medical
courses of action for pilots who experience prolonged symptoms, based
on what the NESC Team believes is the reason for these symptoms. Beyond
that, the identification of precise biomarkers in hypoxic-ischemic
injury in general, e.g. in victims of stroke, is still very much in the
research phase, and not yet suitable for general diagnostic use, as in
this case. [See page 26.]
?
=======================================================================
QUESTIONS SUBMITTED BY MEMBERS POST HEARING
September 13, 2012
=======================================================================
QUESTIONS SUBMITTED BY MR. BARTLETT
Mr. Bartlett. What have been the physiological consequences to the
pilots in the reported hypoxia incidents? Have you categorized each of
these incidents in terms of level of seriousness of the reported event?
If so, what does the data show?
General Lyon. There have been no long term physiologic consequences
to pilots that have reported hypoxia incidents. Four pilots were
treated in hyperbaric conditions due to the nature of their medical
complaints. All pilots who reported hypoxia incidents have been
medically returned to flying status. Level of seriousness is generally
categorized by mishap/incident class. Classes of mishaps range from
Class A (the most serious) to Class E (the least serious). Pilots who
have reported hypoxia have categorically been Class E incidents.
The data shows there have been no biomarkers found in the aircraft
or pilots pointing to contamination in the breathing gas.
Mr. Bartlett. What are the operational impacts to the current
restrictions on F-22 operations? Are F-22s capable of operating
throughout their full operational envelope if required to do so?
General Lyon. F-22 aircraft are currently restricted to 44,000 feet
during training missions with limited operational impacts. If required
to do so, F-22 aircraft can operate throughout their full operational
envelope.
Mr. Bartlett. What is the status of actions on recommendations of
General Martin's Aircraft Oxygen Generation Study Group?
General Lyon. The Scientific Advisory Board (SAB) made a total of
fourteen (14) recommendations; eight (8) short term and six (6) long
term. The Air Force has completed seven (7) of the eight (8) short term
recommendations. The remaining short term recommendation for Helmet
Mounted Pulse Oxygen (HMPO) is on schedule to be completed in December
of 2012.
The six (6) remaining long term recommendations are on track for
completion by the end of FY 2015.
Mr. Bartlett. Is there a cost and time estimate to institute the
planned actions to the F-22 life support system?
General Lyon. Acquisition efforts are underway that include an
Automatic Backup Oxygen System (A-BOS), Automatic Ground Collision and
Avoidance System (AGCAS), Upper Pressure Garment Valve, Oxygen Hose
Pass-Thru Panel, and Helmet Mounted Pulse Oximeter. These efforts are
estimated to cost a total of $82.5M to develop and install on the
entire fleet of F-22 aircraft.
Mr. Bartlett. On what basis was the F-22 returned to flight in
September 2011, since the Scientific Advisory Board and your Study
Group had not completed their work?
General Lyon. The Commander, Air Combat Command tasked ACC/A3 to
implement the SAB study group's recommendations and to return the F-22
fleet to flight operations in late August 2011. The SAB study group's
recommendations were:
1. Incorporate additional aircraft life support inspections and
modifications
2. Standardize OBOGS equipment to the ``-109'' configuration
3. Implement an OBOGS ground-based maintenance inspection
procedure
4. Modify pilot life support equipment to incorporate the use of
the C2A1 chemical warfare filter
5. Implement new post-incident medical and logistics protocols
6. Collect medical baseline blood samples for pilots and selected
maintenance personnel who perform engine ground-run tests
7. Conduct baseline pulmonary function tests for pilots
8. Incorporate finger-mounted pulse oximeters into aircrew flight
equipment
9. Eliminate the 25,000, mean sea level altitude flight
restriction
10. Communicate the results of the investigations, testing and the
advisory board's findings.
In addition, Air Combat Command directed F-22 units to accomplish
life support academics, emphasized oxygen delivery/life support
emergency procedure training, and initiated guidance that directed
pilots to terminate flight operations at the first sign/symptom of a
physiological event. The F-22 community resumed flight operations on 21
Sep 2011 after the Secretary of the Air Force approved the F-22A
``Return to Fly'' Plan. The plan integrated the collective inputs of
the operations, logistics, medical, safety and advisory board
disciplines that had investigated the F-22 over the previous 3 years.
The determination to resume flight operations balanced the current
understanding of risk and the operational imperative to retain the
readiness of the nation's Air Dominance fighter fleet. Pilot combat
mission readiness skills are a perishable skill set. Some skills are
retained through the use of flight simulators, other skills are not.
Emerging insights from the 16 Nov 2010 fatal mishap--insights delayed
by the inability to excavate the crash site until the summer thaw in
Alaska, new inspection criteria for F-22 life support system components
which ensure the veracity of the components, testing which began to
eliminate ambiguities/uncertainties of previous physiological
incidents; all coalesced to permit a thoughtful calculation to resume
flight operations.
Mr. Bartlett. What is the status of the Air Combat Command's Life
Support Systems Task Force report, and when will it be released? Would
you provide the committee a copy of the report when it is completed?
General Lyon. The LSS TF final report is currently in draft with an
estimated completion date of 31 Oct 2012. The report will be vetted
through Headquarters Air Force and be available once released by Air
Force leadership.
Mr. Bartlett. We understand that the upper pressure garment was
also used in F-15s and F-16s from the early 1990s through 2005. Why
weren't vulnerabilities in the upper pressure garment determined while
it was in use with the F-15 and F-16? Are there differences in the
upper pressure garment system in the F-22 compared to the F-15 and F-
16?
General Lyon. The Upper Pressure Garment (UPG) system being used in
the F-22 is fully functional, compatible with, and meets all
requirements for use with F-15 and F-16 aircraft. The physiological
root cause investigation concluded the UPG was prematurely inflating
due to the F-22's safety positive pressure breathing system. Neither
the F-15 nor F-16 has safety positive pressure breathing systems.
Mr. Bartlett. Why have ground maintenance personnel experienced
symptoms if the issue is primarily linked to life support systems
inside the cockpit?
General Lyon. All ground incidents which occurred between 22 Sep
2011 and 14 Dec 2011 were extensively investigated. All ground incident
aircraft underwent contamination inspection prior to return to flight
in September 2011 as well as more extensive post incident testing. This
testing contributed to some of the overall F-22 contamination analysis.
None of the ground incident aircraft cockpit testing revealed anything
approaching a remarkable health guidance value. None of the maintainer
blood, breath or urine samples indicated anything remarkable. Fluid
found in the cockpit of one incident aircraft was evaluated and
determined to be water with nothing remarkable.
During one incident, investigators suspected tailwind engine
exhaust may reach the cockpit and possibly effect maintainers. However,
post incident testing and continued testing on two F-22 aircraft has
indicated nothing remarkable. Engine run qualified ground maintenance
personnel did receive updated engine run procedures to increase
awareness, and to allow them to shutdown and reposition aircraft or
equipment in the event of excessive exhaust. Engine run maintenance
personnel also carried air sampling canisters in the cockpit for
several months to capture any air samples from any potential incidents.
However, no incidents occurred during this timeframe which was
subsequent to the last ground incident in Dec 2011. Maintainers across
the F-22 fleet perform in excess of a hundred engine runs every month--
runs which do not include aircraft movement. The Air Force has trained
and implemented procedures for maintainers to quickly and safely shut
down a running aircraft in the event of any future incidents.
Additionally, appropriate aircraft and medical protocols are in place
to respond to any future incidents.
Mr. Bartlett. Please describe the Air Force's efforts to
definitively determine that stealth coatings, along with other
contaminants, did not cause any of these incidents. Could stealth
coatings that were heated either on the ground or in flight cause
contamination in that manner?
General Lyon. LO Coatings and its breakdown products, along with
other potential contaminants were incorporated into an extensive
Molecular Characterization Matrix effort that thoroughly characterized,
analyzed and documented over 900 compounds that could be present in
aircraft environments. After several years of exhaustive testing both
on the ground and in flight, no detected compounds levels have ever
exceeded safe limits, or even been close to safe limit thresholds.
All potential compound sources in an F-22 were evaluated including
fuel, hydraulic fluid, engine oil, radar coolant, ambient air, engine
exhaust, aircraft cleaning products, sealants, and coatings. Source
breakdown analysis was performed and potential source information was
incorporated into the Molecular Characterization Matrix for each
compound. Of the 900 compounds characterized, only approximately 450
were ever detected on an F-22 aircraft.
Compound detection methods used on F-22 aircraft were capable of
detecting a full spectrum of compounds. Detection media included
Thermal Desorption Tubes, SUMMA canisters, multi-RAEs, sock and swab
analyses, Greywolf, PUF/XAD, Silica Gel, C2A1 filters and GRIMM/CPC
particulate counter, among others. The detection methods used were
capable of detecting a wide range of particulate matter, volatile and
semi-volatile compounds, and standard gases. Over 2,000 total samples
were taken using these devices, at different times, both on ground and
in-flight. Chemists and toxicologists performed countless reviews of
sampling techniques and methods and culminated their effort with a
detection methods expert forum to ensure that the full spectrum of
aircraft compounds would have been adequately detected by the methods
used in testing and sample analysis.
Post incident protocols were established as part of Return to
Flight in September 2011 and completed after each incident flight and
maintainer incident. The protocol directed sampling at various areas of
the aircraft including cockpit and breathing line air. All incident
aircraft had levels of detected compounds well below established safe
limits.
Safe limits were developed with a team of over 20 experienced
toxicologists, doctors, and scientists from contractor, NASA,
University, and USAF personnel. These limits were derived from
established OSHA guidelines, existing available research, Permissible
Exposure Limits (PELs), Short Term Exposure Limits (STELs), and other
established guidelines for each compound. In addition to aircraft
sampling, blood, urine, and exhaled breath samples were taken from all
incident pilots and maintainers and reviewed by an independent medical
team of 5 physiologists, toxicologists, and aerospace physicians from
the contractor, USAF, University and NASA. No abnormalities were noted
in any tests. If a pilot was exposed to reactive LO coating materials,
pilot blood tests should have revealed abnormal levels of heavy metals
present. None were detected.
A thorough review of maintenance activities on incident aircraft
was completed and there were no maintenance trends prior to incident
flights. Incidents have not been linked to any specific maintenance
activities, including initial LO application and/or coating repair.
In addition, compounds unique to LO coatings are unlikely to still
be present in their reactive state during flight operations, since
precautions are taken when coatings are applied. The aircraft is
isolated to prevent exposure to personnel and Technical Order Documents
(TOD) dictate that the aircraft are not returned to flight line
operations until coatings are cured and paints are dry. Therefore, it
is highly unlikely that these coatings were present during ground or
in-flight operations.
Based on the exhaustive research conducted to date, the team
believes that contamination is not the root cause of the F-22
Physiological Incidents.
Mr. Bartlett. How do F-22 g-forces cause what is referred to as
``Raptor cough''? Why does the Air Force feel it is not related to the
physiological incidents pilots are experiencing?
General Lyon. The term ``Raptor Cough'' is commonly known as
acceleration atelectasis. Acceleration atelectasis results from pilots
breathing high concentrations of oxygen (above 60%) while wearing anti-
G trousers, and exposure to G-forces. Atelectasis refers to the closure
of alveoli in the terminal bronchioles as oxygen is absorbed into the
blood stream, leaving no component of normal breathing gas (i.e.
nitrogen) to keep them open. The normal physiologic response to re-open
the alveoli is to cough. The F-22 consistently delivers higher
concentrations of oxygen compared to legacy fighters increasing
susceptibility to developing atelectasis.
The Air Force feels that atelectasis may be a contributor to the
``Raptor Cough'' issue. The Air Force will continue to explore further
potential causes through long term breathing air analysis and human
systems integration efforts.
Mr. Bartlett. What is the Air Force's level of confidence in
whether or not the life support equipment issues are contributing to
all of the physiological incidents with pilots and ground personnel in
the F-22 community?
General Lyon. The Root Cause Corrective Action (RCCA) team
exhaustively investigated 414 separate fault tree branches to arrive at
high confidence in the overall F-22 Life Support System equipment. The
Upper Pressure Garment (UPG) valve is the only remaining vulnerability,
and is on-track for resolution in December 2012.
The F-22 LSS Task Force is very confident that we know what was
causing physiological incidents. No single cause was identified; rather
multiple factors defined during the root cause corrective action (RCCA)
combine to produce symptoms. These factors include human factors,
breathing system impedance, high O2 concentration, and Upper Pressure
Garment restriction caused by a fill/dump valve that was not
specifically designed for the F-22. Pilot/Maintainer variability
contributes to symptom manifestation differences. We are also confident
that factors other than the life support system or the aircraft caused
the ground incidents.
Mr. Bartlett. You have previously indicated that of the 11 reported
``cause unknown'' hypoxia events since return to fly in September 2011,
less than half of those events are still unresolved. How many of the
reported incidents can you contribute to an insufficient supply of
oxygen?
General Lyon. Of the 11 reported ``cause unknown'' events since
September 2011, all 11 have been resolved under the general cause of
restricted breathing. This determination was made through the
independent investigations made at each mishap wing, supported by
personnel and resources at the major command level along with experts
from the F-22 program office, Lockheed-Martin, and outside support from
experts at the U.S. Navy and NASA.
Date Event Description20-Oct-11 Hypoxia symptoms on departure--restricted breathing
20-Oct-11 Post flight personnel recognized cognitive degradation from pilot--restricted breathing
31 Oct 11 Pilot experienced symptoms in flight--restricted breathing
15 Nov 11 Pilot experienced symptoms during high-G sortie--restricted breathing
14 Dec 11 Hypoxia symptoms in flight--restricted breathing
14 Feb 12 Confusion during/post flight--restricted breathing
17 Feb 12 Confusion during intercept trng--restricted breathing
17 Feb 12 Confusion during RTB--restricted breathing
23 Feb 12 Hypoxia symptoms during RTB--restricted breathing
1 Mar 12 Pilot confusion, Spatial D in IMC--restricted breathing
8 Mar 12 Hypoxia symptoms during night RTB--restricted breathing
Mr. Bartlett. You have previously indicated that of the 11 reported
``cause unknown'' hypoxia events since return to fly in September 2011,
less than half of those events are still unresolved. Could you provide
an update on the status of each of those events including which are
resolved with a cause for each, and which are still unresolved and
actions being taken to address those unresolved cases?
General Lyon. All of the events since September 2011 have been
resolved under the general cause of restricted breathing. This
determination was made through the independent investigations made at
each mishap wing, supported by personnel and resources at the major
command level along with experts from the F-22 program office,
Lockheed-Martin, and outside support from experts at the U.S. Navy and
NASA.
Date Event Description20-Oct-11 Hypoxia symptoms on departure--restricted breathing
20-Oct-11 Post flight personnel recognized cognitive degradation from pilot--restricted breathing
31 Oct 11 Pilot experienced symptoms in flight--restricted breathing
15 Nov 11 Pilot experienced symptoms during high-G sortie--restricted breathing
14 Dec 11 Hypoxia symptoms in flight--restricted breathing
14 Feb 12 Confusion during/post flight--restricted breathing
17 Feb 12 Confusion during intercept trng--restricted breathing
17 Feb 12 Confusion during RTB--restricted breathing
23 Feb 12 Hypoxia symptoms during RTB--restricted breathing
1 Mar 12 Pilot confusion, Spatial D in IMC--restricted breathing
8 Mar 12 Hypoxia symptoms during night RTB--restricted breathing
Mr. Bartlett. Were you provided access to any Air Force data or
facilities your team deemed necessary to carry out your review of the
Air Force's investigative process and root-cause analysis?
Mr. Cragg. Yes, the USAF provided the NASA Engineering and Safety
Center (NESC) F-22 Life Support System (LSS) Independent Analysis Team
with access to all of the data and facilities needed.
Mr. Bartlett. You mentioned in your written statement that you
believed insufficient human-systems integration testing was
accomplished before operational deployment of the F-22. What additional
testing do you believe should have been accomplished?
Mr. Cragg. One of the NESC's Team's recommendations was to ensure
appropriate human system integration testing is performed before
operational use of any new system or implementation of a change to an
existing system. Life support components (e.g., the On-Board Oxygen
Generator (OBOGs)) were all individually qualified and put into the
system by a system integrator. The original F-22 qualification testing
did not utilize the same Aircrew Flight Equipment (AFE) that is in use
today. Many of the complex interactions between the end-to-end system
and the pilots were just recently identified during the human
centrifuge and altitude chamber testing.
Mr. Bartlett. You noted in your written statement that in any jet
fighter environment, irritant compounds like combustion exhaust gases,
fuels, lubricants, and organic cleaning solvents can be present. Are
you confident in the Air Force's analysis that irritant compounds could
not be in the pilot's breathing air supply thereby causing hypoxia-like
effects?
Mr. Cragg. As stated, irritant compounds are present in any jet
fighter environment, including the F-22. The NESC Team found no
evidence of a contaminant producing a toxic exposure for the pilots
flying the F-22. The NESC Team recommended that the USAF ``Consider a
fundamental reassessment of requirements and assumptions for LSS in
high performance aircraft.'' Such an assessment would provide a better
understanding of the physiological effects of irritant compounds in
high performance aircraft.
Mr. Bartlett. What is the status of the NASA Engineering and Safety
Center report, and when will it be released? Would you provide the
committee a copy of the report when it is completed?
Mr. Cragg. The USAF requested NASA's review of hypoxia-like issues
with the F-22. On August 31, 2012, the NESC presented the USAF with the
final report. Accordingly, the USAF is responsible for any further use
or release of the report, and NASA has agreed to defer to the USAF on
such requests.
Mr. Bartlett. Are you confident that, in addition to removing the
filter, improvements to the pilots' gear, such as the upper pressure
garment, will fix the F-22's physiological problems?
Mr. Cragg. The NESC Team believes that there are multiple issues
affecting the pilot's physiology in the F-22. Addressing each of these
issues will ensure that the hypoxia-like symptoms will become less
likely. Removing the C2A1 filter that exacerbated the problems and
fixing the Upper Pressure Garment are major improvements.
______
QUESTIONS SUBMITTED BY MR. RUNYAN
Mr. Runyan. General Martin, in your testimony before the
subcommittee, you stated that the decision to pull the backup oxygen
system was made by a lower level team, not the chief engineer
supervising the program. It was also stated that this was done to save
weight and that assumptions were made that the main oxygen system would
be improved to accommodate, however there was no coordination between
the two teams and the main oxygen system did not receive any
improvements to make up for the lack of a backup system. General Lyon
and General Martin, please provide the full name(s) of each of the
person(s) who made the decisions, what his/her/their current position
is for each person who signed off, and what actions have been taken to
hold these people accountable for their decisions in light of
subsequent events. Thank you.
General Martin. The decision to remove the F-22 Back-Up Oxygen
capability was made at an F-22 Cockpit Requirements/Design Review
Update on Wednesday, 15 Jan 92. ``B/U Oxygen--OBOGS'' was one of the 7
trade studies reviewed during this requirements/design review. The
minutes of this review clearly show concurrence with the trade study
recommendation to ``delete dedicated standby oxygen supply requirement
for OBOGS backup'' and ``use emergency oxygen for emergencies.'' There
were 25 government members at this meeting. After a thorough review of
the Air Force's historical F-22 records, we are unable to determine
who, specifically, made the decision to remove the F-22 Back-Up Oxygen
capability from the F-22 design. Similarly, we have identified no
instances in which adverse action was taken against an Air Force
employee as a result of his/her making such a decision.
Mr. Runyan. Do you think that you have found the actual cause of
the problem? What is the source of the ``Raptor cough''?
General Martin. The source of the ``Raptor Cough'' is a combination
of breathing high concentrations of oxygen, wear of anti-G trousers,
and exposure to G forces. Raptor Cough is commonly known as
acceleration atelectasis. Acceleration atelectasis results from pilots
breathing high concentrations of oxygen (above 60%) while wearing anti-
G trousers, and exposure to G-forces. Atelectasis refers to the closure
of alveoli in the terminal bronchioles as oxygen is absorbed into the
blood stream, leaving no component of normal breathing gas (i.e.
nitrogen) to keep them open. The normal physiologic response to re-open
the alveoli is to cough. The F-22 consistently delivers higher
concentrations of oxygen compared to legacy fighters increasing
susceptibility to developing atelectasis.
The Air Force feels that atelectasis may be a contributor to the
``Raptor Cough'' issue. The Air Force will continue to explore further
potential causes through long term breathing air analysis and human
systems integration efforts.
Mr. Runyan. Can the F-22 be retrofitted with a current oxygen
system that we can have full confidence in?
General Martin. The Air Force has full confidence in the current F-
22 On-Board Oxygen Generation System based on our extensive testing
during the F-22 Life Support System root cause investigation.
Mr. Runyan. General Martin, in your testimony before the
subcommittee, you stated that the decision to pull the backup oxygen
system was made by a lower level team, not the chief engineer
supervising the program. It was also stated that this was done to save
weight and that assumptions were made that the main oxygen system would
be improved to accommodate, however there was no coordination between
the two teams and the main oxygen system did not receive any
improvements to make up for the lack of a backup system. General Lyon
and General Martin, please provide the full name(s) of each of the
person(s) who made the decisions, what his/her/their current position
is for each person who signed off, and what actions have been taken to
hold these people accountable for their decisions in light of
subsequent events. Thank you.
General Lyon. The decision to remove the F-22 Back-Up Oxygen
capability was made at an F-22 Cockpit Requirements/Design Review
Update on Wednesday, 15 Jan 92. ``B/U Oxygen--OBOGS'' was one of the 7
trade studies reviewed during this requirements/design review. The
minutes of this review clearly show concurrence with the trade study
recommendation to ``delete dedicated standby oxygen supply requirement
for OBOGS backup'' and ``use emergency oxygen for emergencies.'' There
were 25 government members at this meeting. After a thorough review of
the Air Force's historical F-22 records, we are unable to determine
who, specifically, made the decision to remove the F-22 Back-Up Oxygen
capability from the F-22 design. Similarly, we have identified no
instances in which adverse action was taken against an Air Force
employee as a result of his/her making such a decision.
Mr. Runyan. Do you think that you have found the actual cause of
the problem? What is the source of the ``Raptor cough''?
General Lyon. The source of the ``Raptor Cough'' is a combination
of breathing high concentrations of oxygen, wear of anti-G trousers,
and exposure to G forces. Raptor Cough is commonly known as
acceleration atelectasis. Acceleration atelectasis results from pilots
breathing high concentrations of oxygen (above 60%) while wearing anti-
G trousers, and exposure to G-forces. Atelectasis refers to the closure
of alveoli in the terminal bronchioles as oxygen is absorbed into the
blood stream, leaving no component of normal breathing gas (i.e.
nitrogen) to keep them open. The normal physiologic response to re-open
the alveoli is to cough. The F-22 consistently delivers higher
concentrations of oxygen compared to legacy fighters increasing
susceptibility to developing atelectasis.
The Air Force feels that atelectasis may be a contributor to the
``Raptor Cough'' issue. The Air Force will continue to explore further
potential causes through long term breathing air analysis and human
systems integration efforts.
Mr. Runyan. Can the F-22 be retrofitted with a current oxygen
system that we can have full confidence in?
General Lyon. The Air Force has full confidence in the current F-22
On-Board Oxygen Generation System based on our extensive testing during
the F-22 Life Support System root cause investigation.
Mr. Runyan. Why is the ACC commander, General Hostage, not at the
hearing? Does he not consider this situation a serious problem? As a
member of both the House Armed Services and House Veterans Affairs
Committees, I would also like to have heard testimony directly from him
since this all ultimately falls under his responsibility as ACC
Commander.
General Lyon. General Mike Hostage is happy to address any
additional concerns of the committee anytime he is called. On this
occasion, Maj Gen Lyon was called by the committee to appear on 13
September. As General Hostage's most senior staff officer and ACC's
Director of Air and Space Operations, Maj Gen Lyon was appointed to
lead the F-22 Life Support System (LSS) Task Force by the Secretary of
the Air Force. This represented a major commitment of headquarters
efforts. As LSS lead, Maj Gen Lyon was empowered to speak for the Air
Force on the subject. He holds the seniority and position to speak
authoritatively, and has the most comprehensive knowledge of the
subject.
General Hostage made F-22 pilot safety and operational capability a
top priority for ACC through his orders, commitment of time and
resources, and personal actions. Due to the seriousness of his
concerns, General Hostage closely monitored the situation and made all
the key decisions on this issue, such as approving the F-22s return to
flying operations.
Lastly, General Hostage took the step of becoming an F-22 pilot
himself in order to gain firsthand knowledge of operating the aircraft,
and to demonstrate his belief that the overall risk levels our pilots
take while operating the F-22 is comparable with that associated with
most other high performance aircraft, given the numerous corrective
actions and operating guidelines now in place.
Mr. Runyan. Do you think that you have found the actual cause of
the problem? What is the source of the ``Raptor cough''?
Mr. Cragg. The NESC Team believes that there are multiple issues
affecting the pilot's physiology in the F-22. Addressing each of these
issues will ensure that the hypoxia-like symptoms will become less
likely. Removing the C2A1 filter that exacerbated the problems,
adjusting the oxygen schedule down from ``Max,'' and fixing the Upper
Pressure Garment are major improvements. The NESC Team believes that
the ``Raptor Cough'' is likely caused by a combination of atelectasis,
high oxygen concentrations, and other physiological factors.
Mr. Runyan. Can the F-22 be retrofitted with a current oxygen
system that we can have full confidence in?
Mr. Cragg. The NESC Team believes that the current Honeywell On
Board Oxygen Generator (OBOGs) is operating properly and as designed.
______
QUESTIONS SUBMITTED BY MS. SPEIER
Ms. Speier. General Martin, you mentioned that the F-22 program's
ability to detect these issues was degraded by the Air Force's
increased reliance upon contractors. Do you know approximately what the
ratio of government to contractor employees working on human systems
integration was in the Air Force then, and what that ratio is now?
General Martin. Thank you for the opportunity to clarify and expand
on this issue. Although the Panel did not specifically review the ratio
of government to contractor manning with regard to the human systems
integration competencies, based on what the Panel members heard from
contractor and USAF personnel with deep experience in the human system
fields, the degradation in the ``detection of issues'' resulted from an
overall reduction in government and contractor expertise in the field
of human systems expertise within both the Air Force and the contractor
community that occurred over a more than 20-year period beginning in
1990.
In this context, ``human systems'' encompasses human factors
engineering, human systems integration, aerospace physiology (research
and operational), and aerospace life support systems design/
development/testing/evaluation. A significant reduction in manning and
funding, for both the government and contractor workforces dealing with
Human System Integration, Aviation Physiology, or Flight Medicine
(especially in altitude physiology, altitude protection, oxygen
generation systems, and occupational toxicology) occurred during the
years of the F-22's engineering, development and manufacturing (EMD)
phase and during its operational fielding. In Appendix E of the SAB's
Aircraft Oxygen Generation Study Final Report, a discussion of that
reduction is more fully described. Specifically, during the 1996-2000
period, Air Force Research Laboratory Human Effectiveness manpower (and
the associated research funding) for continuing human effectiveness
activities (including research and development of human systems
integration, aviation physiology and flight medicine) was reduced by 44
percent. The Air Force indicated at the time it was willing to accept a
higher risk in the application of human-centered technologies; and in
particular, aircraft cockpit design technologies, environmental
protection research, and life support systems were considered
sufficiently mature that future research and development could
therefore be accomplished by industry.
While the Air Force can and does rely on contractor expertise in
many fields that type of contractor-provided ``expert force in being''
exists only when funded over a period of time so that expertise can be
developed and maintained at a high level. The contractor community does
maintain certain (limited) ``core'' sets of technical expertise from
within its own resources for vital future business reasons. However,
the aerospace physiology and life support areas, especially as
applicable to high performance military aircraft, represent a long term
high commitment/low return area and in general, contractors have not
maintained that technical expertise without significant continuing
support (i.e., government funding/contracts for basic and applied
research). Although in a slightly different context, the USAF faces
much the same problem and, as mentioned above, has reduced its research
capabilities and expertise accordingly.
Ms. Speier. One of the findings of the Scientific Advisory Board
was that the Air Force had insufficient capabilities and expertise for
human systems integration. How does the Air Force plan to improve this
expertise?
General Lyon. The Air Force recognized the need to reestablish the
Human Systems Integration competency in 2007 when we created the Air
Force Human Systems Integration Office (AFHSIO) as a direct reporting
agency to the Vice Chief of Staff of the Air Force. A recognition of
the relationship of this office to weapon systems development resulted
in a realignment of this office to the Undersecretary of the Air Force
for Acquisition in 2009. The AFHSIO serves as a central policy source
and tracking center for human systems integration (HSI) in acquisition
programs. The team is currently assessing the number of HSI
practitioners required, developing a concept of operations (CONOPS) for
supporting program offices, determining training and certification
required, and establishing a reporting mechanism.
Ms. Speier. General Lyon, the Safety Advisory Board recommended
more clearly defining inherently governmental roles and
responsibilities in the Air Force's acquisition processes and core
competencies. How has the Air Force responded to this recommendation?
General Lyon. The Office of the Deputy Assistant Secretary of the
Air Force for Acquisition Integration (SAF/AQX) reviewed, updated,
published guidance, and reported the results of their review to the
Military Deputy, Office of the Secretary of the Air Force for
Acquisition (SAF/AQ).
Ms. Speier. Mr. Cragg, you said that your team's conclusions ``do
not represent an exhaustive review of all F-22 documentation.'' What
other documentation would an exhaustive review include?
Mr. Cragg. The NESC Team would define ``exhaustive review'' to
include review and evaluation of every single document and data source.
An exhaustive review requires a significant amount of time and
personnel. Based on the NESC Team's experience, the key documents
necessary to understand the situation and to provide significant
recommendations to the USAF were identified and reviewed.
Ms. Speier. Mr. Cragg, what issues should the Air Force explore in
any studies of the long term impacts of the F-22's physiological
strain?
Mr. Cragg. The NESC Team believes that in some cases there could be
a hypoxic-ischemic injury to certain areas of the brain that accounts
for the prolonged neurocognitive symptoms experienced by some pilots.
Based on early discussions with USAF medical representatives, a more
objective assessment of neurocognitive function (e.g. computerized
testing), as well as certain imaging studies (e.g. MRI of the brain),
may be warranted in pilots who experience prolonged hypoxia-like
symptoms associated with F-22 flight. Pulmonary function and diffusion
testing for all F-22 pilots should also be considered. Further
specifics of such testing (e.g. type and frequency) would best be
addressed by technical experts in this field.
______
QUESTIONS SUBMITTED BY MR. LOEBSACK
Mr. Loebsack. What solutions has the Air Force reviewed to solve
the hypoxia problems experienced by pilots? Specifically, what oxygen
delivery system changes have been reviewed and were all available
solutions reviewed?
General Martin. The Air Force has reviewed various proposed
solutions to the hypoxia problems experienced by pilots. Included are
modifications to the breathing assembly such as the Raptor 2
modification which introduced a chemical warfare canister in-line with
air supply to the pilot. This was done to mitigate potential
contamination before this theory was disproven. Further, the Air Force
required pilots to wear pulse oximeters for the first time in history
in an attempt to quantify arterial blood saturation.
We have reviewed numerous other potential solutions including
modifications to the aircraft and have concluded that adding an
automatic back-up oxygen system would meet requirements to have
immediate 100% oxygen available in the event of a rapid decompression
at extreme high altitudes. Other potential solutions investigated
included changing the oxygen source from the current on board system to
liquid and/or gaseous oxygen systems.
Mr. Loebsack. Since the Air Force pointed to the recent travel of
F-22s to Japan as an indicator that the hypoxia problem has been
solved, does that mean that there were no risk mitigation restrictions
placed on the F-22s during the transit?
General Martin. The Air Force has kept all risk mitigation measures
in place during F-22 long duration flights. Since resuming long-
distance F-22 missions in February 2012, the Air Force has completed
over 100 long-distance F-22 sorties, totaling over 650 hours. There
have been zero conditions or physiological incidents during any of
these sorties that would require the use of these risk mitigation
measures. After thorough investigation there is no data to suggest that
these risk mitigations are any more necessary on long-duration F-22
movements than with any other USAF fighter aircraft.
Mr. Loebsack. What solutions has the Air Force reviewed to solve
the hypoxia problems experienced by pilots? Specifically, what oxygen
delivery system changes have been reviewed and were all available
solutions reviewed?
General Lyon. The Air Force has reviewed various proposed solutions
to the hypoxia problems experienced by pilots. Included are
modifications to the breathing assembly such as the Raptor 2
modification which introduced a chemical warfare canister in-line with
air supply to the pilot. This was done to mitigate potential
contamination before this theory was disproven. Further, the Air Force
required pilots to wear pulse oximeters for the first time in history
in an attempt to quantify arterial blood saturation.
Mr. Loebsack. Since the Air Force pointed to the recent travel of
F-22s to Japan as an indicator that the hypoxia problem has been
solved, does that mean that there were no risk mitigation restrictions
placed on the F-22s during the transit?
General Lyon. The Air Force has kept all risk mitigation measures
in place during F-22 long duration flights. Since resuming long-
distance F-22 missions in February 2012, the Air Force has completed
over 100 long-distance F-22 sorties, totaling over 650 hours. There
have been zero conditions or physiological incidents during any of
these sorties that would require the use of these risk mitigation
measures. After thorough investigation there is no data to suggest that
these risk mitigations are any more necessary on long-duration F-22
movements than with any other USAF fighter aircraft.