Special Conditions: Boeing Model 747-8/-8F Series Airplanes; Design Roll Maneuver Requirement, 2434-2435 [2010-662]

Agencies

• Federal Aviation Administration
• DEPARTMENT OF TRANSPORTATION

[Federal Register Volume 75, Number 10 (Friday, January 15, 2010)]
[Rules and Regulations]
[Pages 2434-2435]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2010-662]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 25

[Docket No. NM414; Special Conditions No. 25-402-SC]


Special Conditions: Boeing Model 747-8/-8F Series Airplanes; 
Design Roll Maneuver Requirement

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final special conditions.

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SUMMARY: These special conditions are issued for the Boeing Model 747-
8/-8F airplane. This airplane will have novel or unusual design 
features when compared to the state of technology envisioned in the 
airworthiness standards for transport category airplanes. These design 
features include an electronic flight control system that provides roll 
control of the airplane through pilot inputs to the flight computers. 
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. 
Additional special conditions will be issued for other novel or unusual 
design features of the Boeing 747-8/-8F airplanes.

DATES: Effective Date: February 16, 2010.

FOR FURTHER INFORMATION CONTACT: Todd Martin, FAA, Airframe and Cabin 
Safety Branch, ANM-115, Transport Airplane Directorate, Aircraft 
Certification Service, 1601 Lind Avenue, SW., Renton, Washington 98057-
3356; telephone (425) 227-1178; facsimile (425) 227-1232.

SUPPLEMENTARY INFORMATION: On November 4, 2005, The Boeing Company, PO 
Box 3707, Seattle, WA 98124, applied for an amendment to Type 
Certificate Number A20WE to include the new Model 747-8 series 
passenger airplane and the new Model 747-8F freighter airplane. The 
Model 747-8 and the Model 747-8F are derivatives of the 747-400 and the 
747-400F, respectively. Both the Model 747-8 and the Model 747-8F are 
four-engine jet transport airplanes that will have a maximum takeoff 
weight of 975,000 pounds and new General Electric GEnx -2B67 engines. 
The Model 747-8 will have two flight crew and the capacity to carry 660 
passengers.

Type Certification Basis

    Under the provisions of Title 14, Code of Federal Regulations (14 
CFR) 21.101, Boeing must show that the Model 747-8 and 747-8F 
(hereafter referred as 747-8/-8F series) meet the applicable provisions 
of part 25, as amended by Amendments 25-1 through 25-117, except for 
earlier amendments as agreed upon by the FAA. These regulations will be 
incorporated into Type Certificate No. A20WE after type certification 
approval of the 747-8/-8F.
    In addition, the certification basis includes other regulations, 
special conditions and exemptions that are not relevant to these 
special conditions. Type Certificate No. A20WE will be updated to 
include a complete description of the certification basis for these 
airplanes.
    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 747-8/-8F because of a novel or 
unusual design feature, special conditions are prescribed under the 
provisions of Sec.  21.16.
    In addition to the applicable airworthiness regulations and special 
conditions, the 747-8/-8F series 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.
    Special conditions, as defined in Sec.  11.19, are issued under 
Sec.  11.38, and become part of the type certification basis under 
Sec.  21.101.
    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 or series that incorporates the same 
or similar novel or unusual design feature, or should any other model 
or series already included on the same type certificate be modified to 
incorporate the same or similar novel or unusual design feature, the 
special conditions would also apply to the other model or series under 
Sec.  21.101.

New or Unusual Design Features

    The Boeing Model 747-8/-8F will incorporate the following novel or 
unusual design features: An electronic flight control system that 
provides roll control of the airplane through pilot inputs to the 
flight computers.

[[Page 2435]]

Discussion

    The 747-8/-8F is equipped with an electronic flight control system 
that provides roll control of the airplane through pilot inputs to the 
flight computers. Current part 25 airworthiness regulations account for 
``control laws,'' for which aileron deflection is proportional to 
control wheel deflection. They do not address any nonlinearities \1\ or 
other effects on aileron and spoiler actuation that may be caused by 
electronic flight controls. Therefore, the FAA considers the flight 
control system to be a novel and unusual feature compared to those 
envisioned when current regulations were adopted. Since this type of 
system may affect flight loads, and therefore the structural capability 
of the airplane, special conditions are needed to address these 
effects.
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    \1\ A nonlinearity is a situation where output does not change 
in the same proportion as input.
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    These special conditions differ from current requirements in that 
the special conditions require that the roll maneuver result from 
defined movements of the cockpit 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 cockpit roll control is returned to neutral following the 
initial roll input.
    These special conditions differ from similar special conditions 
applied to previous designs. These special conditions are limited to 
the roll axis only, whereas previous special conditions also included 
pitch and yaw axes. A special condition is 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 
condition is needed for the pitch axis because the current requirement 
(Sec.  25.331(c)) is adequate.

Discussion of Comments

    Notice of proposed special conditions No. 25-09-10-SC for the 
Boeing Model 747-8/-8F airplanes was published in the Federal Register 
on October 8, 2009 (74 FR 51813). No comments were received.

Applicability

    As discussed above, these special conditions are applicable to the 
Boeing Model 747-8/-8F airplanes. 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 features, these special 
conditions would apply to that model as well under the provisions of 
Sec.  21.101.

Conclusion

    This action affects only certain novel or unusual design features 
of the Boeing Model 747-8/-8F airplanes. It is not a rule of general 
applicability.

List of Subjects in 14 CFR Part 25

    Aircraft, Aviation safety, Reporting and recordkeeping 
requirements.

0
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 the Boeing Model 747-8/-8F airplanes.
    In lieu of compliance with Sec.  25.349(a), the Boeing Model 747-8/
-8F must comply with the following special conditions.
    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 
separately, 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 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 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.
    (c) 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 paragraph (b).
    (d) 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 paragraph (b).

    Issued in Renton, Washington, on January 5, 2010.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 2010-662 Filed 1-14-10; 8:45 am]
BILLING CODE 4910-13-P