[Federal Register Volume 73, Number 39 (Wednesday, February 27, 2008)]
[Rules and Regulations]
[Pages 10379-10380]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: E8-3714]



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  Federal Register / Vol. 73, No. 39 / Wednesday, February 27, 2008 / 
Rules and Regulations  

[[Page 10379]]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 25

[Docket No. NM378 Special Conditions No. 25-365-SC]


Special Conditions: Boeing Model 787-8 Airplane; Operation 
Without Normal Electrical Power

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final Special Conditions.

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SUMMARY: These special conditions are issued for the Boeing Model 787-8 
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. The Boeing Model 787-8 
airplane will have numerous electrically operated systems whose 
function is needed for continued safe flight and landing of the 
airplane. For these design features, the applicable airworthiness 
regulations do not contain adequate or appropriate safety standards. 
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 standards. Additional 
special conditions have been issued for other novel or unusual design 
features of the Boeing Model 787-8 airplanes.

DATES: Effective Date: March 28, 2008.

FOR FURTHER INFORMATION CONTACT: Stephen Slotte, FAA, Airplane & Flight 
Crew Interface Branch, ANM-111, Transport Airplane Directorate, 
Aircraft Certification Service, 1601 Lind Avenue, SW., Renton, 
Washington 98057-3356; telephone (425) 227-2315; facsimile (425) 227-
1320.

SUPPLEMENTARY INFORMATION: 

Background

    On March 28, 2003, Boeing applied for an FAA type certificate for 
its new Boeing Model 787-8 passenger airplane. The Boeing Model 787-8 
airplane will be an all-new, two-engine jet transport airplane with a 
two-aisle cabin. The maximum takeoff weight will be 476,000 pounds, 
with a maximum passenger count of 381 passengers.

Type Certification Basis

     Under provisions of 14 Code of Federal Regulations (CFR) 21.17, 
Boeing must show that Boeing Model 787-8 airplanes (hereafter referred 
to as ``the 787'') meet the applicable provisions of 14 CFR part 25, as 
amended by Amendments 25-1 through 25-117, except Sec. Sec.  25.809(a) 
and 25.812, which will remain at Amendment 25-115. If the Administrator 
finds that the applicable airworthiness regulations do not contain 
adequate or appropriate safety standards for the 787 because of a novel 
or unusual design feature, special conditions are prescribed under 
provisions of 14 CFR 21.16.
    In addition to the applicable airworthiness regulations and special 
conditions, the 787 must comply with the fuel vent and exhaust emission 
requirements of 14 CFR part 34 and the noise certification requirements 
of part 36. The FAA must also issue a finding of regulatory adequacy 
pursuant to section 611 of Public Law 92-574, the ``Noise Control Act 
of 1972.''
    The FAA issues special conditions, as defined in Sec.  11.19, under 
Sec.  11.38, and they become part of the type certification basis under 
Sec.  21.17(a)(2).
    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 or similar 
novel or unusual design feature, the special conditions would also 
apply to the other model under Sec.  21.101.

Novel or Unusual Design Features

    The 787 will incorporate a number of novel or unusual design 
features, some of which have not been previously installed on large 
commercial aircraft. Because of these design features, these special 
conditions differ from similar previous special conditions for other 
airplane models. Because of rapid improvements in airplane technology, 
the applicable airworthiness regulations do not contain adequate or 
appropriate safety standards for these design features. These special 
conditions for the 787 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.
    In addition to an electronic flight control system, a number of 
systems that have traditionally been pneumatically or mechanically 
operated have been implemented as electrically powered systems on the 
787. Examples include the hydraulic power, equipment cooling, wing 
anti-ice, and auxiliary power unit (APU) and engine start systems. The 
criticality of some of these systems is such that their failure would 
either reduce the capability of the airplane or the ability of the crew 
to cope with adverse operating conditions, or prevent continued safe 
flight and landing of the airplane. The airworthiness standards of part 
25 do not contain adequate or appropriate standards for protection of 
these systems from the adverse effects of operation without normal 
electrical power.
    The current rule, 14 CFR 25.1351(d), Amendment 25-72, requires safe 
operation under visual flight rules (VFR) conditions for at least five 
minutes after loss of all normal electrical power. This rule was 
structured around traditional airplane designs that used mechanical 
control cables and linkages for flight control. These manual controls 
allowed the crew to maintain aerodynamic control of the airplane for an 
indefinite period of time after loss of all electrical power. Under 
those conditions, the mechanical flight control system provided the 
crew with the ability to fly the airplane while attempting to identify 
the cause of the electrical failure, start the engine(s) if necessary, 
and reestablish some of the electrical power generation capability, if 
possible.
    To maintain the same level of safety associated with traditional 
designs, Boeing must design the 787 for operation with the normal 
sources of engine- and auxiliary-power-unit (APU)-generated electrical 
power not working. Service experience has shown that loss of all 
electrical power from the airplane's engine- and APU-driven generators 
is not extremely improbable. Thus, Boeing must show that the

[[Page 10380]]

airplane is capable of recovering adequate primary electrical power 
generation for safe flight and landing. This demonstration would 
provide that the ability to restore operation of portions of the 
electrical power generation capability would be considered if 
unrecoverable loss of those portions is shown to be extremely 
improbable. An alternative source of electrical power would have to be 
provided for the time necessary to restore the minimum power generation 
capability necessary for safe flight and landing.

Discussion of Comments

    Notice of Proposed Special Conditions No. 25-07-11-SC for the 787 
was published in the Federal Register on October 16, 2007 (72 FR 
58560). No comments were received on this proposal, and we are issuing 
these special conditions as proposed.

Applicability

     As discussed above, these special conditions are applicable to the 
787. Should Boeing apply at a later date for a change to the type 
certificate to include another model on the same type certificate 
incorporating the same novel or unusual design features, these special 
conditions would apply to that model as well.

Conclusion

     This action affects only certain novel or unusual design features 
of the 787. 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

     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 787-8 airplane.
    In lieu of the requirements of 14 CFR 25.1351(d), the following 
special conditions apply:
    (1) The applicant must show by test or a combination of test and 
analysis that the airplane is capable of continued safe flight and 
landing with all normal sources of engine- and auxiliary-power-unit 
(APU)-generated electrical power inoperative, as prescribed by 
paragraphs (1)(a) and (1)(b) below. For purposes of this special 
condition, normal sources of electrical power generation do not include 
any alternate power sources such as the battery, ram air turbine (RAT), 
or independent power systems such as the flight control permanent 
magnet generating system. In showing capability for continued safe 
flight and landing, consideration must be given to systems capability, 
effects on crew workload and operating conditions, and the 
physiological needs of the flightcrew and passengers for the longest 
diversion time for which approval is sought.
    (a) Common cause failures, cascading failures, and zonal physical 
threats must be considered in showing compliance with this requirement.
    (b) In showing compliance with this requirement, the ability to 
restore operation of portions of the electrical power generation and 
distribution system may be considered if it can be shown that 
unrecoverable loss of those portions of the system is extremely 
improbable. An alternative source of electrical power must be provided 
for the time required to restore the minimum electrical power 
generation capability required for safe flight and landing. 
(Unrecoverable loss of all engines may be excluded when showing that 
unrecoverable loss of critical portions of the electrical system is 
extremely improbable.)
    (2) Regardless of any electrical generation and distribution system 
recovery capability shown under paragraph 1, sufficient electrical 
system capability must be provided--
    (a) to allow time to descend, with all engines inoperative, at the 
speed that provides the best glide slope, from the maximum operating 
altitude to the altitude at which the soonest possible engine restart 
could be accomplished, and
    (b) to subsequently allow multiple start attempts of the engines 
and APU. This capability must be provided in addition to the electrical 
capability required by existing part 25 requirements related to 
operation with all engines inoperative.
    (3) The electrical energy used by the airplane in descending with 
engines inoperative from the maximum operating altitude at the best 
glide slope, and in making multiple attempts to start the engines and 
APU, must be considered when showing compliance with paragraphs (1) and 
(2) of these special conditions and with existing 14 CFR part 25 
requirements related to continued safe flight and landing.

    Issued in Renton, Washington, on February 13, 2008.
Stephen P. Boyd,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
 [FR Doc. E8-3714 Filed 2-26-08; 8:45 am]
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