Defense Acquisitions: Readiness of the Marine Corps' V-22
Aircraft for Full-Rate Production (20-FEB-01, GAO-01-369R).
GAO concludes that the V-22 program is not ready for full-rate
production. This conclusion is based on two factors. First, GAO's
"best practices" work has identified practices used by successful
commercial and defense programs to develop and produce quality
products in significantly less time and at lower costs. GAO
reviews of major weapons systems have shown that failure to
follow these practices results in cost increases, schedule
delays, and performance problems. Second, GAO analyzed
Department of Defense (DOD) assessments and data on the V-22
program and interviewed DOD officials. As a result of GAO's
findings, DOD postponed the full-rate production of the V-22
aircraft until the risks have been mitigated.
-------------------------Indexing Terms-------------------------
REPORTNUM: GAO-01-369R
ACCNO: 164520
TITLE: Defense Acquisitions: Readiness of the Marine Corps' V-22
Aircraft for Full-Rate Production
DATE: 02/20/2001
SUBJECT: Aircraft research
Developmental testing
Military aircraft
Military procurement
Operational testing
Private sector practices
Weapons research and development
Osprey
V-22 Aircraft
******************************************************************
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GAO-01-369R
Defense Acquisitions
United States General Accounting Office Washington, DC 20548
February 20, 2001 The Honorable Donald H. Rumsfeld The Secretary of Defense
Subject: Defense Acquisitions: Readiness of the Marine Corps' V- 22 Aircraft
for Full- Rate Production
Dear Mr. Secretary: In a letter to Secretary of Defense Cohen, dated
December 15, 2000, we stated that the Marine Corps' V- 22 aircraft 1 was not
ready for full- rate production and that the Secretary had made a prudent
decision to defer that production decision until the V- 22 Blue Ribbon Panel
reports its findings. 2 On January 12, 2001, we provided the Panel with
additional details at their request. A copy of the briefing and briefing
support material that we presented to the Panel are in enclosures I and II.
Our conclusions about the program's readiness for full- rate production are
based on two factors. First, our “best practices” work, which
has identified practices used by successful commercial and defense programs
to develop and produce quality products in significantly less time and at
lower costs. 3 Our reviews of numerous major weapon systems has shown that
failure to follow these practices has led to cost increases, schedule
delays, and performance problems. Second, our analysis of Department of
Defense assessments and data relevant to the V- 22 program and interviews
with relevant Department officials.
Our best practices work over the past few years has shown that successful
system development efforts resolve major technology, design, and
manufacturing uncertainties prior to the start of production. Thorough test
and evaluation, when done early, increase the probability that systems will
achieve required performance levels within agreed- upon time and cost
parameters. In July 2000, we reported on how best commercial practices for
testing and evaluating new products offer ways to improve the way the
Department conducts test and evaluation on weapon systems. 4 In commenting
on our report, the Department stated that it is committed to
1 The V- 22 Osprey is a tilt- rotor, short- take- off- and- landing
aircraft, which was developed to satisfy various combat missions, including
medium- lift assault for the Marine Corps. 2 The Panel was appointed by
former Secretary of Defense Cohen to review the V- 22 Program.
3 See particularly, Best Practices: Successful Application to Weapon
Acquisitions Requires Changes in DOD's Environment (GAO/ NSIAD- 98- 56, Feb.
24, 1998). 4 Best Practices: A More Constructive Test Approach Is Key to
Better Weapon System Outcomes (GAO/ NSIAD- 00- 199, July 31, 2000).
GAO- 01- 369R Defense Acquisitions Page 2 establishing appropriate levels of
product maturity, validating those levels with
appropriate testing and evaluation, and providing the required mix of
testing and evaluation tools necessary to validate maturity.
In contrast to best commercial practices, our work has shown that numerous
weapon system programs suffer from persistent problems associated with late
or incomplete testing. This practice pushes the burden of discovery late in
development when problems become very costly to resolve. We also found that
testing operated under a penalty environment that creates perverse
incentives. For example, if tests were not passed, the program might look
less attractive and be vulnerable to funding cuts. Managers thus had
incentives to postpone difficult tests and limit open communication about
test results. These represent widespread and systemic problems within the
Department that must be addressed.
Our review of the V- 22 program, which is already in low- rate initial
production, revealed that the Department planned to proceed with a full-
rate production decision without knowing whether new technology could meet
Marine Corps requirements; whether the design would work as required; or
whether the design could be produced within cost, schedule, and quality
targets. This knowledge is lacking in part because of inadequate test and
evaluation. Specifically, developmental testing was deleted, deferred, or
simulated in order to meet cost and schedule goals. For example, the
original plan to test the flying qualities of the flight control system
included significant testing to be conducted in helicopter and aircraft
conversion modes at various rates of descent, speeds, and weights. This
would have provided considerable knowledge of V- 22 flying qualities
especially in areas where the Marine Corps states the aircraft is
susceptible to a sudden loss of controlled flight. 5 To meet cost and
schedule targets, the actual testing conducted was less than a third of that
originally planned.
Documents we reviewed indicated that test waivers and limitations reduced
testing for operational realism. For example, air combat maneuvering was
prohibited and the aircraft was not cleared to operate in icing conditions.
Further, major concerns about the aircraft's performance and operations
remain unresolved. These were highlighted in a report prepared by Defense's
Director, Operational Test and Evaluation. 6 For example, the report said
the aircraft (1) is susceptible to sudden loss of controlled flight under
certain conditions, (2) creates downward force from the V- 22 proprotor
blades that could potentially interfere with operations below or close to
the aircraft, 7 and (3) is far less reliable than what is required. These
known and potential problems and their associated costs, leave open the
question of the V- 22's real value- as demonstrated- for Marine Corps
operations.
In November 2000, we briefed Marine Corps, Department of the Navy, and
Office of the Secretary of Defense officials on the results of our review
and our assessment of
5 Known as “vortex ring state.” 6 Combined Operational Test &
Evaluation and Live Fire Test & Evaluation Report on the V- 22 Osprey,
November 17, 2000. 7 Known as “downwash.”
GAO- 01- 369R Defense Acquisitions Page 3 the risks of proceeding into full-
rate production at that time. Our work was
conducted from September through December 2000 in accordance with generally
accepted government auditing standards.
We provided a draft of this report to the Department of Defense for its
review and comment. The Department stated its recently approved acquisition
policy recognizes the need for testing and evaluation and includes
procedures for demonstrating technology maturity prior to entering the
system integration or low- rate initial production acquisition phase of a
program. The Department also stated that V- 22 program decisions have been
deferred to permit consideration of the results of the Panel to Review the
V- 22 Program and of the Department of Defense Inspector General's
investigation into fleet maintenance practices. Further, the panel and the
Inspector General's investigation will help define the risks and responses
appropriate for the current state of the V- 22. The Department also provided
some technical comments, which we incorporated into the report, where
appropriate. The Department's comments are included as enclosure III.
*** *** *** We are sending copies of this letter to interested congressional
committees; the Honorable Robert B. Pirie, Jr., Acting Secretary of the
Navy; the Honorable Lawrence J. Delaney, Acting Secretary of the Air Force;
and General James Jones, Commandant of the Marine Corps. Copies of this
letter will also be made available on GAO's home page at http:// www. gao.
gov.
If you have any questions concerning this report, please contact me on (202)
512- 4841. Major contributors to this report were Robert L. Pelletier, Jerry
W. Clark, and Stacy Edwards.
Sincerely yours, Signed Katherine V. Schinasi Director, Acquisition and
Sourcing Management
Enclosures
Page 4 PRESENTATION TO
THE V- 22 BLUE RIBBON PANEL
JANUARY 12, 2001
Enclosure I
Page 5 Knowledge at Key Junctures Is Critical
to a Successful Transition to Production
Unknowns Knowns Knowledge Point 1: Knowledge that a match exists between
technology and requirements. Knowledge Point 2: Knowledge that the design
will work as required. Knowledge Point 3: Knowledge that the design can be
produced within cost, schedule, and quality targets
DOD Product Development
Knowledge Point 1 Knowledge Point 2
Knowledge Point 3 Production Start Program Launch
Best Commercial Product Development
Production Start Program Launch Knowledge Point 1
Knowledge Point 2 Knowledge Point 3
Enclosure I
Page 6
Summary - Significant Risk With Proceeding With Full- Rate Production
KNOWLEDGE OF V- 22 DESIGN AND PERFORMANCE PARAMETERS FALLS SHORT OF WHAT
SHOULD HAVE BEEN KNOWN BEFORE BEGINNING PRODUCTION
? DEVELOPMENTAL FLIGHT TESTING WAS DELETED, DEFERRED, OR SIMULATED
? OPERATIONAL TEST WAIVERS AND LIMITATIONS REDUCED TESTING FOR OPERATIONAL
REALISM
? ASSESSMENT BASED ON REDUCED SYSTEM REQUIREMENTS
? MAJOR CONCERNS RAISED IN OPEVAL, JAG REPORT, OPEVAL DATABASE, DOT& E,
OTHERS
Enclosure I
Page 7
Significant Risk With Proceeding With Full- Rate Production (cont.)
? RISKS OF MOVING FORWARD WITHOUT ADDITIONAL KNOWLEDGE
? VALUE OF SYSTEM FOR MARINE CORPS OPERATIONS NOT YET ESTABLISHED
? CONNECTION BETWEEN DEMONSTRATED PROBLEMS NOT KNOWN; UNKNOWN PROBLEMS NOT
DISCOVERED
? FPIF/ CPIF CONTRACT EXPOSES GOVERNMENT TO RESPONSIBILITY TO FUND ANY
DESIGN MODIFICATIONS - SOME, PERHAPS SIGNIFICANT, CHANGES ARE LIKELY
? LONGER TERM RISK TO MODERNIZATION ACCOUNT, AS COST INCREASES BEYOND
ALREADY BUDGETED FUNDS ARE LIKELY
? MARINE CORPS BUDGET IMPACTED BY MAINTAINABILITY SHORTFALLS
Enclosure I
Page 8
Current V- 22 Effort
? Current analysis (begun in Sept. 2000) based on our review of program
documents and interviews with officials responsible for managing and
overseeing V- 22 development
? We reviewed numerous program documents, such as
? test plans and requirements documents
? development test reports
? early/ limited operational test reports
? development/ operational transition reports
? operational test database
? Navy and DOT& E reports of operational test results
? results of program oversight including deficiency reports
? JAG and other V- 22 crash (April 2000) investigation documents
Enclosure I
Page 9
Current V- 22 Effort (cont.)
? We interviewed the following:
? V- 22 Program Manager
? V- 22 Lead Program Engineer
? V- 22 ITT officials
? Navy Warfare Requirements (N- 88) officials
? Navy Test and Evaluation (NO- 91) officials
? Navy Bureau of Inspections and Survey officials
? V- 22 Operational Test Director
? Director, Operational Test and Evaluation
Enclosure I
Page 10
Current V- 22 Effort (cont.)
? Briefed our preliminary results to DOD and Navy officials responsible for
execution and oversight of the V- 22 development effort in November 2000
? V- 22 Program Manager
? DOD's Director, Operational Test and Evaluation
? Secretary of the Navy (Research, Development & Acquisition) Deputy
Assistant Secretary (Air Programs)
Enclosure I
Page 11
GAO FINDINGS - DEVELOPMENTAL FLIGHT TESTING WAS DELETED, DEFERRED, OR
SIMULATED
? Restructured baseline development flight test program numerous times to
meet program cost and schedule pressures
? Deleted significant testing that would have provided additional knowledge
on V- 22 flying qualities and susceptibility to Vortex Ring State
? Deferred tests of “height velocity (HV) diagram,” which
identifies aircraft “no fly zones,” until after OPEVAL
? Increased use of simulators proposed to reduce need for manned flights
? However, Navy INSURV readiness for OPEVAL report and OPTEVFOR's V- 22
OPEVAL report concluded that simulations could not be use for two key test
areas
Enclosure I
Page 12
GAO FINDINGS - OPERATIONAL TEST WAIVERS AND LIMITATIONS REDUCED TESTING FOR
OPERATIONAL REALISM
? Prior to OPEVAL, program management requested and was granted operational
test waivers due to
? failure to meet criteria,
? inability to meet ORD threshold requirements, and
? Part I deficiencies (impact missions; high probability of aircraft loss,
equipment damage, or personnel injuries during missions; or excessive
operator compensation required to accomplish missions) identified during
development tests
? INSURV approved the V- 22 for OPEVAL with Part I deficiencies based on
plans to resolve the deficiencies
? DOT& E reported that several waivers created major or minor limitations to
OPEVAL
Enclosure I
Page 13
GAO FINDINGS - OPERATIONAL TEST WAIVERS AND LIMITATIONS REDUCED TESTING FOR
OPERATIONAL REALISM (cont.)
? Additional limitations, warnings, and cautions were imposed on operations
through flight clearance messages at various points during operational test
? Numerous shipboard operation restrictions
? Rescue hoist and rescue hoist fast rope operations prohibited
? Operations prohibited within 25nm of lightning activity for unmodified
aircraft
? Formation flight allowed only with 250 ft. separation
? Flight maneuver restrictions (max angle of bank and Gs)
? Flight prohibited in icing conditions
Enclosure I
Page 14
GAO FINDINGS - OPERATIONAL ASSESSMENT BASED ON REDUCED SYSTEM REQUIREMENTS
Critical Operational Issues (COI) eliminated from test master plan (TEMP)
revised prior to OPEVAL
? Revised 1999 TEMP reduced number of effectiveness COIs from 7 to 4
? Amphibious operations, Marine Expeditionary Unit (Special Operations
Capable), and joint interoperability eliminated from previous (1995) TEMP
Enclosure I
Page 15
GAO FINDINGS - OPERATIONAL ASSESSMENT BASED ON REDUCED SYSTEM REQUIREMENTS
(cont.)
Performance Requirements changed in Operational Requirements Document (ORD)
prior to OPEVAL
? Land- based short take- off distance (increased from 500 ft. to 3,000 ft.)
? On- board oxygen supply (reduced from 7 individual stations to 4)
Enclosure I
Page 16
GAO FINDINGS - MAJOR CONCERNS RAISED IN OPEVAL, JAG REPORT, OPEVAL DATABASE,
DOT& E
Vortex Ring State Concerns
? JAG, OPEVAL, and DOT& E reports raise significant concerns about
implications of V- 22 high rate of descent operations
? Susceptibility to high rate of descent and/ or loss of controlled flight
can occur at any time and consequences are exceedingly grave
? V- 22 appears to be less forgiving than conventional helicopters
? Additional testing is needed, including exploration of formation flight
? Follow- on tests will not be completed until CY2002
Enclosure I
Page 17
GAO FINDINGS - MAJOR CONCERNS RAISED IN OPEVAL, JAG REPORT, OPEVAL DATABASE,
DOT& E (cont.)
Rotor Downwash Concerns
? OPEVAL report cites some concern about downwash - V- 22 operational test
database lists numerous concerns about impact of rotor downwash
? Creates brownout and whiteout conditions
? Makes fast rope and rescue hoist operations hazardous
? Reduces effectiveness of combatants
? Forces sand, snow, other matter into interior of aircraft and into
aircraft components
? DOT& E final report lists downwash as an area of concern
? Testing demonstrated that some required capabilities can be achieved with
great difficulty, some capabilities are unlikely to be achieved, and some
planned capabilities have yet to be tested for downwash effects
Enclosure I
Page 18
GAO FINDINGS - MAJOR CONCERNS RAISED IN OPEVAL, JAG REPORT, OPEVAL DATABASE,
DOT& E (cont.)
Cabin Dimensions/ Environment Concerns
? Concerns raised about carrying 24 combat Marines and their equipment
? Cabin environment cannot be adequately controlled to prevent extreme
temperature conditions
Enclosure I
Page 19
GAO FINDINGS - MAJOR CONCERNS RAISED IN OPEVAL, JAG REPORT, OPEVAL DATABASE,
DOT& E (cont.)
Suitability Concerns
? INSURV report - MV- 22 fails to meet mean flight hours between failure and
built- in- test false alarm rate test parameters - low reliability of the
MV- 22 aircraft weapon system poses the most significant risk to OT- IIE
(OPEVAL)
? OPEVAL report - Weapon system certified as ready for operational test and
evaluation was immature and exhibited significant production deficiencies,
which caused excessive unplanned maintenance actions
? DOT& E report - MV- 22 demonstrated marginal system reliability, excessive
maintenance manpower and logistic support requirements, and inadequate
availability. V- 22 availability, maintainability, and reliability rates
compared unfavorably with fleet CH- 46 experience and will pose a
significant maintenance burden
Enclosure I
Page 20
GAO ASSESSMENT
? BEST PRACTICES ARE CLOSELY CORRELATED WITH SUCCESSFUL PROGRAM OUTCOMES
? DESIGN AND PROCESS MATURITY BEFORE BEGINNING PRODUCTION
? KNOWLEDGE GAINED IN V- 22 PROGRAM FALLS SIGNIFICANTLY SHORT OF SUCCESSFUL
PROGRAMS
? PROCEEDING INTO PRODUCTION BEFORE ADDITIONAL KNOWLEDGE IS GAINED POSES
RISKS FOR DOD OPERATIONS AND BUDGETS
Enclosure I
Page 21
RELATED GAO REPORTS
? GAO has significant and varied experience addressing the DOD acquisition
process including system development and operational testing
? October 1997 - GAO/ NSIAD- 98- 13, NAVY AVIATION: V- 22 Cost and
Capability to Meet Requirements Are Yet To Be Determined
? April 2000 - GAO/ NSIAD- OO- 75, DEFENSE ACQUISITIONS: Need to Revise
Acquisition Strategy to Reduce Risk for Joint Airto- Surface Standoff
Missile
? May 2000 - GAO/ NSIAD- OO- 158, DEFENSE ACQUISITIONS: F/ A- 18E/ F
Aircraft Does Not Meet All Criteria for Multiyear Procurement
? May 2000 - GAO/ NSIAD- 00- 74, JOINT STRIKE FIGHTER ACQUISITION:
Development Schedule Should Be Changed to Reduce Risks
? July 2000 - GAO/ NSIAD- OO- 182, DEFENSE ACQUISITIONS: Howitzer Program
Experiencing Cost Increase and Schedule Delays
? July 2000 - GAO/ NSIAD- OO- 199, BEST PRACTICES: A More Constructive Test
Approach Is Key to Better Weapon System Outcomes
? August 2000 - GAO/ NSIAD- OO- 178, DEFENSE ACQUISITIONS: Recent F- 22
Production Cost Estimates Exceeded Congressional Limitations
? Forthcoming - GAO- 01- 288, BEST PRACTICES: Better Matching of Needs and
Resources Will Lead to Better Weapon System Outcomes
Enclosure I
Page 22
PRESENTATION TO THE V- 22 BLUE RIBBON
PANEL BRIEFING SUPPORT MATERIAL
JANUARY 12, 2001
Enclosure II
Page 23
Briefing Support Material - Developmental Flight Testing Was Deleted,
Deferred, Or Simulated ( Page 11)
Development flight test program started Feb. 1997 and immediately fell
behind schedule
? Restructuring was required due to aircraft modifications, pilot currency,
added unknown test requirements, and significant unplanned maintenance
? Concurrent testing, extension of maintenance intervals, extended flying
used to achieve restructured goals, removal of baseline test requirements,
and use of manned flight simulator
? Deferred/ deleted development tests. Flight Control System Development
Flying Qualities Testing, which included tests for the investigation of
“Vortex Ring State” was reduced from 103 test conditions to 49.
This reduced the scope of testing required for cost and schedule recovery.
Of the 49 test conditions only 33 were actually flown - 16 conditions not
flown were at 0, 40, and 80 knots at high gross weights,
? Simulated development tests. a) INSURV concerned that contractor
simulation model does not have adequate data to model autorotation, b)
OPEVAL reported that contractor simulator did not replicate loss of
controlled flight resulting from HROD
Enclosure II
Page 24
Briefing Support Material - Operational Test Waivers and Limitations Reduced
Testing for Operational Realism (Page 12)
? 21 operational test waivers requested
? One waiver requested for failure to meet criteria - V- 22 mean time
between failure and false alarm rate
? 11 waivers requested for failure to meet requirements due to Part I
deficiencies
? Inadequate cargo handling system
? Exterior lighting for NVG formation flight inadequate
? External loads interferes with radar altimeter
? Lower cabin door operation in hover
? Autorotation descent cannot be maintained while attempting engine air
start, etc.
? 9 waivers requested due to inability to meet ORD thresholds
? Not cleared to operate in icing conditions
? Not cleared for air combat maneuvering
? Not cleared for aerial refueling
? Unable to fastrope out of cabin door, etc.
Enclosure II
Page 25
Briefing Support Material - Operational Test Waivers and Limitations Reduced
Testing for Operational Realism (Page 12)
? Navy Board of Inspection and Survey recommended that the MV- 22 proceed to
OPEVAL contingent upon CNO (N- 88) approval of a plan to resolve a number of
Part I deficiencies. These included deficiencies with published
“Yellow Sheet Reports” and others that were unpublished (draft)
? Part ** I - 3 open (failure of proprotor lightning bond straps, excessive
lightning currents on internal fuel lines, and lateral instability during
shipboard vertical landings)
? Part *I - 11 open (low reliability of MV- 22 aircraft, excessive
lateraldirectional trim requirements during simulated in- flight refueling
at 60- degree nacelle, single mission computer dropouts, exterior lighting
for night vision goggles formation flight inadequate, etc.)
? Part I - 26 open (low reliability of the multifunction display, high false
alarm rate of BIT, unacceptable single mission computer dropouts, no
indication of longitudinal maneuvering capability to the pilot, etc.)
Enclosure II
Page 26
Briefing Support Material - Operational Test Waivers and Limitations Reduced
Testing for Operational Realism (Page 12)
? Deficiencies considered by INSURV to have greatest impact on operational
tests were
? Low reliability of the MV- 22B aircraft weapon system
? Lower cabin door operations in hover
? Air data system faults during conversion mode aerial refueling operations
? Excessive lightning currents on internal fuel lines
? Autorotation survivability
? Inadequate cargo handling system
? Inadequate cockpit/ cabin nuclear, biological, and chemical overpressure
protection
? DOT& E report states that several waivers created major or minor
limitations to OPEVAL
? Not cleared for air combat maneuvering
? Max short take- off (shipboard) weight lower than mission profile specific
weight
? Not cleared for KC- 135 tanker refueling
? Unable to fastrope out of cabin door
Enclosure II
Page 27
Briefing Support Material - Operational Test Waivers and Limitations Reduced
Testing for Operational Realism (Page 13)
? Numerous limitations were imposed at various points in time during
operational tests
? Flight envelope limitations - numerous shipboard operation restrictions,
short takeoff and landing limits, control inputs limits, max takeoff gross
weight limits, max angle of bank limits, max G limits
? Flight control limitations - swashplate actuator fault advisory
restricting airspeed
? Cargo system limitations - ramp limits, parachute OPS prohibited, rescue
hoist OPS prohibited, external cargo OPS prohibited
? Environmental limitations - flight/ ground OPS prohibited within 25nm of
lightning activity for unmodified aircraft
? Fuel system limitations - hover in- flight refueling prohibited, refueling
from KC- 10 prohibited
? Formation flight limitations - wingman shall avoid and not cross lead
aircraft wake during formation flights, 250 ft. lateral and
50 ft. step- up separation shall be maintained
Enclosure II
Page 28
Briefing Support Material - Vortex Ring State (Page 16)
JAG Report - Opinion Section Quotes
?“ After reviewing the evidence collected, it was concerning to see
how ‘easy'
it was for the recipe of uncontrolled flight to be concocted.”
?“ Aircraft performance envelopes are developed, and procedures and
guidance published (NATOPS) to prevent pilots from putting an aircraft in a
situation that would exceed safe parameters. The MV- 22 performance envelope
may be one that fleet pilots can operate within, but given the rigors of
combat, real world operations, and realistic training for both, the
consequences of exceeding this particular envelope appears to be excessively
grave (departure from controlled flight with no warning).”
?“ In traditional rotorcraft, Power Settling would cause uncommanded
rates of descent and, depending on altitude, may result in a hard landing or
quite possibly a controlled crash. In all likelihood, however, such an event
would result in the aircraft at least hitting the ground in an upright
attitude. In this respect, with regard to Vortex Ring State and/ or Blade
Stall, the MV- 22 appears to be less forgiving than conventional
helicopters. A V- 22, because of the approximately 8' 8” distance
because of its prop- rotors, as evidenced by this mishap, is capable of have
one rotor impacted by the effects of Vortex Ring State and/ or Blade Stall
and the other not, resulting in an asymmetrical condition. We believe that
this was the case of the mishap. The end result was a departure from
controlled flight instead of a hard landing or controlled crash .”
?“ There were, however, two other incidents that occurred during
OPEVAL where pilots reported experiencing an uncommanded roll during section
operations... The fact that the causes of these two incidents are not yet
known, coupled with limited developmental formation testing (4 flights for
11.7 hours), make it difficult to completely exclude wake turbulence or
downwash as potential contributors to the mishap.”
Enclosure II
Page 29
Briefing Support Material -Vortex Ring State (cont.) (Page 16)
JAG Report - Recommendation Section Quotes
?“ All V- 22 operators should become acutely familiar with the
potential consequences of high rates- of- descent combined with slow
airspeeds that are present with tiltrotor design. Though all rotorcraft have
the potential to enter into a Vortex Ring condition, recorded occurrences to
date have been rare. The fact that this aircraft no only found itself in a
Vortex Ring State condition with no apparent warning to the aircrew, but
also departed controlled flight is particularly concerning. Until further
testing is conducted on the Vortex Ring State phenomenon, safe flight will
require strict adherence to procedures and limitations.”
?“ PMA- 275, PMA- 205, and the Contractor expedite incorporation of
Vortex Ring State and blade stall warnings and procedures into the MV- 22
NATOPS... The preliminary NATOPS manual and V- 22 ground school syllabus
provides insufficient guidance/ warning as to high rate of descent/ slow
airspeed conditions and the potential consequences.”
?“ That NAVAIR continue to explore the aerodynamic effects of
formation flight with the MV- 22. The MV- 22 will be operationally employed
in a similar fashion to existing fleet aircraft. Multi- ship formations will
be the norm as the aircraft executes its various missions. Questions still
remain concerning potential aerodynamic influences, such as wake turbulence
on wingmen during formation flight. Two
‘anomalies in addition to the mishap occurred during OPEVAL where this
issue was at least a concern.”
Enclosure II
Page 30
Briefing Support Material -Vortex Ring State (cont.) (Page 16)
OPTEVFOR V- 22 OPEVAL Report Quotes
? Summary - “The Naval Air Training and Operating Procedures
Standardization (NATOPS) manual lacked adequate content, accuracy, and
clarity. Additionally, because of incomplete developmental testing in the
high rate of descent (HROD) regime, there was insufficient explanatory or
emphatic text to warn pilots of the hazards of operating in this area. The
flight simulator did not replicate this loss of controlled flight
regime.”
?“ The V- 22 has the potential to enter high rates of descent at high
nacelle angles with low airspeed. This condition occurs very rapidly with
little to no warning to the pilots. In simulation at 95 degrees nacelle, 39
KCAS, and 0 feet per minute rate of descent (ROD), pulling the thrust
control lever (TCL) full aft caused an immediate descent exceeding the 800
feet per minute NATOPS WARNING. If forward TCL is applied at this point, an
uncontrolled flight condition is possible. Within 3 seconds, the simulator
exhibited in excess of 3,000 fpm ROD.”
? Additional Recommendation - “Continue developmental testing to
investigate HROD/ loss of controlled flight phenomena and determine safe
flight envelope for these conditions. Consider providing cockpit warning of
this condition to the pilots to preclude entry into unsafe flight
regimes.”
? Section 4 Test and Results -” The V- 22 technical documentation did
not support the operation and maintenance of the V- 22. The NATOPS was
plagued with inaccuracies that degraded flight operations and still
contained FSD and EMD aircraft data not pertinent to production aircraft.
Performance charts furnished by the developer to support OPEVAL were also
inaccurate when compared to actual flight conditions and the CMS.
Additionally, because of incomplete developmental testing in the HROD
regime, there was insufficient explanatory or emphatic text to warn pilots
of the hazard of operating in this condition.”
Enclosure II
Page 31
Briefing Support Material -Vortex Ring State (cont.) (Page 16)
DOT& E Operational Test and Evaluation Report Quotes
? Executive Summary - “Vortex Ring State can occur in all rotary- wing
aircraft under similar conditions of low airspeed and high sink rate. No
mechanical or electrical failures in the aircraft were found to contribute
to the mishap. In the tiltrotor V- 22, the onset of VRS can occur in the
proprotor on one side without the other side losing lift. In such a case,
the aircraft tends to roll sharply into the side that first loses lift,
resulting in large, unexpected bank angles, followed immediately by rapid
dropping of the nose of the aircraft and a steep dive. At low altitudes,
there may be no opportunity for recovery.”
?“ While the possible existence of VRS in the V- 22 was known when
flight limits for OPEVAL were established, the unusual attitude following
entry into VRS was not expected.”
?“ In addition, testing to date suggests that should a pilot
inadvertently exceed published limitations, there may be no easily
recognizable warning that the aircraft is nearing the danger zone - and some
flight control inputs; e. g., a roll or yaw command, may trigger an
asymmetric thrust condition. Such a situation can easily be envisioned in
flight conditions that place a high workload demand on the pilots; e. g.,
night or low visibility, system malfunctions, hostile fire, etc., should a
breakdown of crew coordination or loss of situational awareness occur. Thus,
the first indication the pilot may receive that he has encountered this
difficulty is when the aircraft initiates an uncommanded, uncontrollable
roll. High rate- of- descent (HROD) testing continues to define the VRS
phenomenon.”
Enclosure II
Page 32
Briefing Support Material -Vortex Ring State (cont.) (Page 16)
DOT& E Operational Test and Evaluation Report Quotes
? Executive Summary - “I believe that ongoing developmental testing
should continue to explore the ability to detect proximity to the danger
area in the flight envelope, with the objective of providing meaningful
warning to the pilot, or control limitations, to avoid entry into this
danger area and loss of control. This area is historically left unexamined
in other military rotorcraft which put in place restrictions that rely on
information non- specific to their particular airframe.”
?“ In addition, follow- on developmental and operational tests should
involve multiple MV- 22s, at heavy weights, in close time and space
proximity as might be anticipated in the conduct of a combat assault
mission. Such operational test would increase confidence that appropriate
tactics exist to enable the MV- 22s to deliver assault forces to a small
area in a short time while avoiding undue exposure to enemy threats- without
subjecting the aircraft to potential loss of control situations.”
? Operational Effectiveness Areas of Concern - “As noted previously, I
fully endorse ongoing testing activities and recommend research efforts to
better understand the Vortex Ring State phenomenon and the potential danger
posed to the safe operation of the MV- 22.”
?“ A second, related concern involves the effects of maneuvering
limitations imposed to avoid the vortex ring state danger area... Despite
the OPEVAL finding that the restrictions had no operational impact, I am
concerned that this constraint imposed to avoid loss of control may limit
the maneuver capability and hence the effectiveness of the MV- 22 in some
operational scenarios. Ongoing developmental flight testing is intended to
more accurately define the danger zone beyond the NATOPS flight
envelope.”
Enclosure II
Page 33
Briefing Support Material -Vortex Ring State (cont.) (Page 16)
DOT& E Operational Test and Evaluation Report Quotes
?“ A second phase of testing is planned by Naval Air Systems Command
to fully explore the potential aerodynamic interactions between MV- 22
aircraft in proximity to each other. Until the final operational constraints
upon descent rates and aircraft separation are established based upon
ongoing developmental testing, and the appropriate tactics are confirmed in
operational testing, the potential impact on the effectiveness of the MV- 22
in performing some combat assault missions must be viewed with some
reservations.”
? Assessment of OPEVAL Adequacy - “Examine thoroughly the
circumstances in which the V- 22 may depart from controlled flight in low-
airspeed, high rates of descent. Investigate the potential for airflow
interactions between nearby V- 22s to initiate or aggravate vortex ring
state.”
?“ Demonstrate the end- to- end conduct of ‘typical OMFTS
scenarios' involving multiple MV- 22s making repeated back- to- back flights
in close proximity in time and space to each other and other aircraft needed
for the operations - as might be expected during the conduct of combat
assault operations.”
?“ Confirm the shipboard compatibility of multiple MV- 22s operating
simultaneously as would be needed in the conduct of a substantive amphibious
assault.”
Enclosure II
Page 34
Briefing Support Material -Suitability Concerns (Page 19)
JAG Report - Opinion Section Quotes
?“ The maintenance/ removal rate of swashplate actuators, though not
causal in this mishap, is concerning. The MOTT replaced 17 actuators during
the OPEVAL period. Given their critical role in the aircraft's drive system,
reliability of these actuators is imperative.”
?“ The frequency of servicing/ maintenance requirements, for aircraft
hydraulic systems, though not causal in this mishap, is concerning. Many
maintenance manhours have been spent maintaining and servicing the various
aircraft hydraulic systems.”
Enclosure II
Page 35
Enclosure III (120039)
Page 35
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