[Federal Register Volume 82, Number 224 (Wednesday, November 22, 2017)]
[Rules and Regulations]
[Pages 55500-55502]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2017-25019]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 25
[Docket No. FAA-2017-0951; Special Conditions No. 25-706-SC]
Special Conditions: Mitsubishi Aircraft Corporation Model MRJ-200
airplane; Design Roll Maneuver for Electronic Flight Controls
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Final special conditions; request for comments.
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SUMMARY: These special conditions are issued for Mitsubishi Aircraft
Corporation (Mitsubishi) Model MRJ-200 airplanes. These airplanes will
have a novel or unusual design feature when compared to the state of
technology
[[Page 55501]]
envisioned in the airworthiness standards for transport category
airplanes. This design feature is an electronic flight-control system
(EFCS) that provides control of the airplane through pilot inputs to
the flight computer. The applicable airworthiness regulations do not
contain adequate or appropriate safety standards for this design
feature. These special conditions contain the additional safety
standards that the Administrator considers necessary to establish a
level of safety equivalent to that established by the existing
airworthiness standards.
DATES: This action is effective on Mitsubishi on November 22, 2017. We
must receive your comments January 8, 2018.
ADDRESSES: Send comments identified by docket number FAA-2017-0951
using any of the following methods:
Federal eRegulations Portal: Go to http://www.regulations.gov/ and follow the online instructions for sending
your comments electronically.
Mail: Send comments to Docket Operations, M-30, U.S.
Department of Transportation (DOT), 1200 New Jersey Avenue SE., Room
W12-140, West Building Ground Floor, Washington, DC 20590-0001.
Hand Delivery or Courier: Take comments to Docket
Operations in Room W12-140 of the West Building Ground Floor at 1200
New Jersey Avenue SE., Washington, DC, between 9 a.m. and 5 p.m.,
Monday through Friday, except Federal holidays.
Fax: Fax comments to Docket Operations at 202-493-2251.
Privacy: The FAA will post all comments it receives, without
change, to http://www.regulations.gov/, including any personal
information the commenter provides. Using the search function of the
docket Web site, anyone can find and read the electronic form of all
comments received into any FAA docket, including the name of the
individual sending the comment (or signing the comment for an
association, business, labor union, etc.). DOT's complete Privacy Act
Statement can be found in the Federal Register published on April 11,
2000 (65 FR 19477-19478).
Docket: Background documents or comments received may be read at
http://www.regulations.gov/ at any time. Follow the online instructions
for accessing the docket or go to Docket Operations in Room W12-140 of
the West Building Ground Floor at 1200 New Jersey Avenue SE.,
Washington, DC, between 9 a.m. and 5 p.m., Monday through Friday,
except Federal holidays.
FOR FURTHER INFORMATION CONTACT: Todd Martin, FAA, Airframe and Cabin
Safety Section, AIR-675, Policy and Innovation Division, Transport
Standards Branch, Aircraft Certification Service, 1601 Lind Avenue SW.,
Renton, Washington 98057-3356; telephone 425-227-1178; facsimile 425-
227-1320.
SUPPLEMENTARY INFORMATION: The FAA has determined that notice of, and
opportunity for prior public comment on, these special conditions is
unnecessary because the substance of these special conditions has been
subject to the public-comment process in several prior instances with
no substantive comments received. The FAA finds good cause that prior
notice and comment are unnecessary, and for the same reason finds that
good cause exists for adopting these special conditions upon
publication in the Federal Register.
Comments Invited
The FAA is requesting comments to allow interested persons to
submit views that may not have been submitted in response to the prior
opportunities for comment described above. We invite interested people
to take part in this rulemaking by sending written comments, data, or
views. The most helpful comments reference a specific portion of the
special conditions, explain the reason for any recommended change, and
include supporting data.
We will consider all comments we receive by the closing date for
comments. We may change these special conditions based on the comments
we receive.
Background
On August 19, 2009, Mitsubishi applied for a type certificate for
their new Model MRJ-200 airplane. The Model MRJ-200 airplane is a low-
wing, conventional-tail design with two wing-mounted turbofan engines.
The airplane is equipped with an electronic flight-control system, has
seating for 96 passengers and a maximum takeoff weight of 98,800 lbs.
Type Certification Basis
Under the provisions of title 14, Code of Federal Regulations (14
CFR) 21.17, Mitsubishi must show that the Model MRJ-200 airplane meets
the applicable provisions of part 25, as amended by Amendments 25-1
through 25-141; part 36, as amended by Amendments 36-1 through 36-30;
and part 34, as amended by Amendments 34-1 through the amendment
effective at the time of design approval.
If the Administrator finds that the applicable airworthiness
regulations (i.e., 14 CFR part 25) do not contain adequate or
appropriate safety standards for the Model MRJ-200 airplane because of
a novel or unusual design feature, special conditions are prescribed
under the provisions of Sec. 21.16.
Special conditions are initially applicable to the Model for which
they are issued. Should the type certificate for that model be amended
later to include any other model that incorporates the same novel or
unusual design feature, these special conditions would also apply to
the other model under Sec. 21.101.
In addition to the applicable airworthiness regulations and special
conditions, the model MRJ-200 airplane must comply with the fuel-vent
and exhaust-emission requirements of 14 CFR part 34, and the noise-
certification requirements of 14 CFR part 36.
The FAA issues special conditions, as defined in 14 CFR 11.19, in
accordance with Sec. 11.38, and they become part of the type
certification basis under Sec. 21.17(a)(2).
Novel or Unusual Design Features
The Model MRJ-200 airplane will incorporate the following novel or
unusual design feature:
An electronic flight-control system that provides control of the
airplane through pilot inputs to the flight computer. Current part 25
airworthiness regulations account for control laws where aileron
deflection is proportional to control-stick deflection. They do not
address any nonlinearities, i.e., situations where output does not
change in the same proportion as input, or other effects on aileron
actuation that may be caused by electronic flight controls.
Discussion
The flight-control system for the Model MRJ-200 airplane does not
have a direct mechanical link, nor a linear gain, between the airplane
flight-control surface and the pilot's flight-deck control device,
which is not accounted for in Sec. 25.349(a). Instead, a flight-
control computer commands the airplane flight-control surfaces, based
on input received from the flight-deck control device. The flight-
control computer modifies pilot input before the command is given to
the flight-control surface.
These special conditions differ from current regulatory
requirements in that they require that the roll maneuvers result from
defined movements of the flight-deck roll control as opposed to defined
aileron deflections. Also, these special conditions require an
additional load condition at design maneuvering speed (VA),
in which the flight-deck roll
[[Page 55502]]
control is returned to neutral following the initial roll input.
These special conditions differ from similar special conditions
previously issued on this topic. These special conditions are limited
to the roll axis only, whereas other special conditions also included
pitch and yaw axes. Special conditions are no longer needed for the yaw
axis because Sec. 25.351 was revised at Amendment 25-91 to take into
account effects of an electronic flight-control system. No special
conditions are needed for the pitch axis because the method that
Mitsubishi proposed for the pitch maneuver takes into account effects
of an electronic flight-control system.
These special conditions contain the additional safety standards
that the Administrator considers necessary to establish a level of
safety equivalent to that established by the existing airworthiness
standards.
Applicability
As discussed above, these special conditions are applicable to the
Model MRJ-200 airplanes. Should Mitsubishi apply at a later date for a
change to the type certificate to include another model incorporating
the same novel or unusual design feature, these special conditions
would apply to that model as well.
Conclusion
This action affects only certain novel or unusual design features
on one model of airplanes. It is not a rule of general applicability.
List of Subjects in 14 CFR Part 25
Aircraft, Aviation safety, Reporting and recordkeeping
requirements.
The authority citation for these special conditions is as follows:
Authority: 49 U.S.C. 106(g), 40113, 44701, 44702, 44704.
The Special Conditions
Accordingly, pursuant to the authority delegated to me by the
Administrator, the following special conditions are issued as part of
the type certification basis for Mitsubishi Model MRJ-200 airplanes.
In lieu of compliance to 14 CFR 25.349(a), the following
conditions, speeds, and flight-deck roll-control motions (except as the
motions may be limited by pilot effort) must be considered in
combination with an airplane load factor of zero, and of two-thirds of
the positive maneuvering factor used in design. In determining the
resulting control-surface deflections, the torsional flexibility of the
wing must be considered in accordance with Sec. 25.301(b).
(a) Conditions corresponding to steady rolling velocities must be
investigated. In addition, conditions corresponding to maximum angular
acceleration must be investigated for airplanes with engines or other
weight concentrations outboard of the fuselage. For the angular
acceleration conditions, zero rolling velocity may be assumed in the
absence of a rational time-history investigation of the maneuver.
(b) At VA, sudden movement of the flight-deck roll
control up to the limit is assumed. The position of the flight-deck
roll control must be maintained until a steady roll rate is achieved,
and then must be returned suddenly to the neutral position.
(c) At VC, the flight-deck roll control must be moved
suddenly and maintained so as to achieve a roll rate not less than that
obtained in special condition (b).
(d) At VD, the flight-deck roll control must be moved
suddenly and maintained so as to achieve a roll rate not less than one
third of that obtained in special condition (b).
Victor Wicklund,
Manager, Transport Standards Branch, Policy and Innovation Division,
Aircraft Certification Service.
[FR Doc. 2017-25019 Filed 11-21-17; 8:45 am]
BILLING CODE 4910-13-P