[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


