82 FR 50500 - Special Conditions: The Boeing Company Model 777-8 and 777-9 Airplanes; Design Roll Maneuver for Electronic Flight Controls

DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration

Federal Register Volume 82, Issue 210 (November 1, 2017)

These special conditions are issued for The Boeing Company (Boeing) Model 777-8 and 777-9 airplanes. These airplanes will have a novel or unusual design feature when compared to the state of technology 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.

[Federal Register Volume 82, Number 210 (Wednesday, November 1, 2017)]
[Rules and Regulations]
[Pages 50500-50502]
From the Federal Register Online  [www.thefederalregister.org]
[FR Doc No: 2017-23701]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 25

[Docket No. FAA-2017-0718; Special Conditions No. 25-705-SC]


Special Conditions: The Boeing Company Model 777-8 and 777-9 
Airplanes; 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 The Boeing Company 
(Boeing) Model 777-8 and 777-9 airplanes. These airplanes will have a 
novel or unusual design feature when compared to the state of 
technology 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 Boeing on November 1, 2017. We must 
receive your comments by December 18, 2017.

[[Page 50501]]


ADDRESSES: Send comments identified by docket number FAA-2017-0718 
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: Mark Freisthler, FAA, Airframe and 
Cabin Safety Branch, AIR-675, Transport Airplane Directorate, Aircraft 
Certification Service, 1601 Lind Avenue SW., Renton, Washington, 98057-
3356; telephone 425-227-1119; facsimile 425-227-1320.

SUPPLEMENTARY INFORMATION: 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 it is 
unnecessary to delay the effective date and 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 April 19, 2017 (for the Model 777-8 airplane), and May 12, 2015 
(for the 777-9 airplane), Boeing applied for an amendment to Type 
Certificate (TC) No. T00001SE to include the new Model 777-8 and 777-9 
airplanes. These airplanes are derivatives of the Model 777-300ER 
airplane currently approved under TC No. T00001SE. The Model 777-9 is a 
stretched-fuselage, large, twin-engine airplane with seating for 408 
passengers and a maximum takeoff weight of 775,000 pounds.
    The Model 777-8, a shortened-body derivative of the 777-9, is a 
large, twin-engine airplane with seating for 359 passengers and a 
maximum takeoff weight of 775,000 pounds.

Type Certification Basis

    Under the provisions of title 14, Code of Federal Regulations (14 
CFR) 21.101, Boeing must show that the Model 777-8 and 777-9 airplanes 
meet the applicable provisions of the regulations listed in TC No. 
T00001SE, or the applicable regulations in effect on the date of 
application for the change, except for earlier amendments as agreed 
upon by the FAA.
    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 777-8 and 777-9 airplanes 
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 features, or should any other model already included on 
the same type certificate be modified to incorporate 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 777-8 and 777-9 airplanes 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.  21.101.

Novel or Unusual Design Features

    The Model 777-8 and 777-9 airplanes 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. The regulations 
do not address nonlinearities, such as 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

    These special conditions differ from current regulatory 
requirements in that they require that the roll maneuver results from 
defined movements of the cockpit roll control, as opposed to defined 
aileron deflections. These special conditions also require an 
additional load condition at design maneuvering speed (VA), 
in which the cockpit roll 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 not required for the pitch 
or yaw axes, because Sec.  25.331 at Amendment 25-141, and Sec.  25.351 
at Amendment 25-91, take into account the 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 
Boeing Model 777-8 and 777-9 airplanes.

[[Page 50502]]

Should Boeing 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 series of airplane. 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

0
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 Boeing Model 777-8 and 777-9 
airplanes.
    In lieu of compliance to 14 CFR 25.349(a), the Model 777-8 and 777-
9 airplanes must comply with the following:
    The following conditions, speeds, and cockpit 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).
    1. 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.
    2. At VA, sudden movement of the cockpit roll control up 
to the limit is assumed. The position of the cockpit roll control must 
be maintained until a steady roll rate is achieved and then must be 
returned suddenly to the neutral position.
    3. At VC, the cockpit roll control must be moved 
suddenly and maintained so as to achieve a roll rate not less than that 
obtained in condition 2, above.
    4. At VD, the cockpit roll control must be moved 
suddenly and maintained so as to achieve a roll rate not less than one 
third of that obtained in condition 2, above.

    Issued in Renton, Washington, on October 25, 2017.
Victor Wicklund,
Manager, Transport Standards Branch, Policy and Innovation Division, 
Aircraft Certification Service.
[FR Doc. 2017-23701 Filed 10-31-17; 8:45 am]
 BILLING CODE 4910-13-P