
[Federal Register Volume 79, Number 33 (Wednesday, February 19, 2014)]
[Rules and Regulations]
[Pages 9379-9380]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2014-03585]



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  Federal Register / Vol. 79, No. 33 / Wednesday, February 19, 2014 / 
Rules and Regulations  

[[Page 9379]]



DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 25

[Docket No. FAA-2013-0858; Special Conditions No. 25-518-SC]


Special Conditions: Bombardier Inc., Models BD-500-1A10 and BD-
500-1A11 Series Airplanes; Fuselage Post-Crash Fire Survivability

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final special conditions.

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SUMMARY: These special conditions are issued for the Bombardier Inc. 
Models BD-500-1A10 and BD-500-1A11 series airplanes. These airplanes 
will have novel or unusual design features when compared to the state 
of technology envisioned in the airworthiness standards for transport 
category airplanes. These features are associated with an aluminum-
lithium fuselage construction that may provide different levels of 
protection from post-crash fire threats than similar aircraft 
constructed from traditional aluminum structure. 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: Effective Date: March 21, 2014.

FOR FURTHER INFORMATION CONTACT: Alan Sinclair, FAA, Airframe and Cabin 
Safety Branch, ANM-115, Transport Airplane Directorate, Aircraft 
Certification Service, 1601 Lind Avenue SW., Renton, Washington, 98057-
3356; telephone (425) 227-2195; facsimile (425) 227-1232.

SUPPLEMENTARY INFORMATION:

Background

    On December 10, 2009, Bombardier Inc. applied for a type 
certificate for their new Models BD-500-1A10 and BD-500-1A11 series 
airplanes (hereafter collectively referred to as ``C-series''). The C-
series airplanes are swept-wing monoplanes with an aluminum alloy 
fuselage sized for 5-abreast seating. Passenger capacity is designated 
as 110 for the Model BD-500-1A10 and 125 for the Model BD-500-1A11. 
Maximum takeoff weight is 131,000 pounds for the Model BD-500-1A10 and 
144,000 pounds for the Model BD-500-1A11.
    The fuselage of the Bombardier C-series airplanes will be 
fabricated using aluminum-lithium construction. Structures fabricated 
from aluminum-lithium may provide different levels of protection from 
post-crash fuel-fed fire threats than similar aircraft with traditional 
aluminum structure.
    There are no existing regulations that adequately ensure that 
aluminum-lithium structure offers passengers the same protection from a 
post-crash fire condition as would a conventional aluminum structure. 
These special conditions are necessary to ensure that the Bombardier C-
series airplanes provide a level of safety equivalent to that provided 
by Title 14, Code of Federal Regulations (14 CFR) part 25.

Type Certification Basis

    Under the provisions of Title 14, Code of Federal Regulations (14 
CFR) 21.17, Bombardier Inc. must show that the C-series airplanes meet 
the applicable provisions of part 25, as amended by Amendment 25-1 
through 25-129 thereto.
    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 C-series 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 feature, the special conditions would also apply to the 
other model under Sec.  21.101.
    In addition to the applicable airworthiness regulations and special 
conditions, the C-series 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; and the FAA must issue a 
finding of regulatory adequacy under Sec.  611 of Public Law 92-574, 
the ``Noise Control Act of 1972.''
    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 Bombardier C-series airplanes will incorporate the following 
novel or unusual design features: The fuselage will be fabricated using 
aluminum-lithium materials instead of conventional aluminum.
    The performance of airplanes consisting of a conventional aluminum 
fuselage is understood based on service history and extensive 
intermediate and large-scale fire testing. The new aluminum-lithium 
materials must provide the same levels of protection against post-crash 
fuel-fed fire threats.

Discussion

    The certification basis for the Bombardier C-series airplanes 
includes meeting the burn through requirements defined in Sec.  
25.856(b). The Bombardier C-series airplanes are introducing a new 
material from what has traditionally been shown to be survivable from a 
toxic standpoint. Toxicity levels from post-crash fire threats are 
typically more severe than threats generated from an in-flight fire 
with regards to the quantity level of toxins produced by off-gases from 
burning materials. Therefore, it is necessary to ensure that the 
material being used does not introduce a new hazard that would reduce 
the survivability of the passengers during a post-crash situation, or 
produce levels of toxic fumes that would be lethal or incapacitating, 
thus preventing evacuation of the aircraft in a crash scenario.
    Bombardier Inc. will have to demonstrate that aluminum-lithium 
material does not produce levels of toxic fumes that will reduce the 
survivability of the passengers or their ability to evacuate when 
compared to typically constructed aluminum airplanes.
    A way of showing acceptable capability is to conduct a laboratory-
scale test to assess the survivability

[[Page 9380]]

characteristics of this non-traditional fuselage material. If 
negligible amounts of combustion products are produced in this test, 
the material can be considered acceptable with respect to post crash 
survivability. A test method developed by the FAA's William J. Hughes 
Technical Center should be used (Ref. DOT/FAA/AR-TN07/15 dated August 
2008).
    Related regulations, including Sec. Sec.  25.853 and 25.856(a), 
remain valid for this airplane, but they do not reflect the potential 
threat generated from toxic levels of gases produced from aluminum-
lithium materials.

Discussion of Comments

    Notice of proposed special conditions No. 25-13-08-SC for the 
Bombardier C-series airplanes was published in the Federal Register on 
October 31, 2013 (78 FR 65233). No comments were received, and the 
special conditions are adopted as proposed.

Applicability

    As discussed above, these special conditions are applicable to the 
Models BD-500-1A10 and BD-500-1A11 series airplanes. Should Bombardier 
Inc. 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 feature, the special conditions would 
apply to that model as well.

Conclusion

    This action affects only certain novel or unusual design features 
on two model series 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 Bombardier Inc. Models BD-500-1A10 and 
BD-500-1A11 (C-series) airplanes.
    Fuselage Post-Crash Fire Survivability. The Bombardier C-series 
airplanes must show that any toxic levels of gases produced from the 
aluminum-lithium material are in no way an additional threat to the 
passengers and their ability to evacuate when compared to a typically 
constructed aluminum airplane exposed to a post-crash fuel-fed fire.

    Issued in Renton, Washington, on January 22, 2014.
Jeffrey E. Duven,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 2014-03585 Filed 2-18-14; 8:45 am]
BILLING CODE 4910-13-P


