
[Federal Register Volume 79, Number 109 (Friday, June 6, 2014)]
[Rules and Regulations]
[Pages 32639-32640]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2014-13243]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 25

[Docket No. FAA-2013-1038; Special Conditions No. 25-549-SC]


Special Conditions: Bombardier Aerospace, Models BD-500-1A10 and 
BD-500-1A11 Series Airplanes; Flight Envelope Protection: High-Speed 
Limiting

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final Special Conditions.

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SUMMARY: These special conditions are issued for the Bombardier 
Aerospace Models BD-500-1A10 and BD-500-1A11 series airplanes. These 
airplanes will have a novel or unusual design feature associated with 
an electronic flight control system that contains fly-by-wire control 
laws, including envelope protections, for the overspeed protection and 
roll-limiting function. 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: July 7, 2014.

FOR FURTHER INFORMATION CONTACT: Joe Jacobsen, FAA, Airplane and Flight 
Crew Interface Branch, ANM-111, Transport Airplane Directorate, 
Aircraft Certification Service, 1601 Lind Avenue SW., Renton, 
Washington 98057-3356; telephone 425-227-2011; facsimile 425-227-1149.

SUPPLEMENTARY INFORMATION: 

Background

    On December 10, 2009, Bombardier Aerospace applied for a type 
certificate for their new Models BD-500-1A10 and BD-500-1A11 series 
airplanes (hereafter collectively referred to as ``CSeries''). The 
CSeries 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 longitudinal control law design of the Bombardier CSeries 
airplanes incorporates an overspeed protection system in the normal 
mode. This mode prevents the pilot from inadvertently or intentionally 
exceeding a speed approximately equivalent to the maximum speed for 
stability characteristics (VFC) or attaining demonstrated 
flight diving speed (VDF). Current Title 14, Code of Federal 
Regulations (14 CFR) part 25 standards did not envision a high-speed 
limiter that might preclude or modify flying qualities assessments in 
the overspeed region.

Type Certification Basis

    Under the provisions of 14 CFR 21.17, Bombardier Aerospace must 
show that the CSeries airplanes meet the applicable provisions of part 
25 as amended by Amendments 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 CSeries 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 or similar 
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 CSeries 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 CSeries airplanes will incorporate the following novel or 
unusual design features: An electronic flight control system that 
contains fly-by-wire control laws, including envelope protections, for 
the overspeed protection and roll-limiting function. Current part 25 
requirements do not contain appropriate standards for high-speed 
protection systems.

Discussion

    The overspeed protection functionality includes multifunction 
spoilers (MFS) that will automatically deploy as speed brakes once the 
airspeed exceeds a small tolerance above maximum operating limit speed 
(Vmo/Mmo); the MFS will retract automatically 
when speed is subsequently reduced. Special conditions are necessary in 
addition to the requirements of Sec.  25.143 for the operation of the 
high-speed protection. The general intent is that the overspeed 
protection does not impede normal maneuvering and speed control, and 
that the overspeed protection does not restrict or prevent emergency 
maneuvering.
    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.

Discussion of Comments

    Notice of proposed special conditions No. 25-13-38-SC for the 
Bombardier CSeries airplanes was published in the Federal Register on 
December 11, 2013 (78 FR 75284). We received one comment in favor of 
the proposed special conditions as written.

Applicability

    As discussed above, these special conditions are applicable to the 
Models BD-500-1A10 and BD-500-1A11 series airplanes. Should Bombardier 
Aerospace apply at a later date for a change to the type certificate to 
include another model 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

[[Page 32640]]

certification basis for the Bombardier Aerospace Models BD-500-1A10 and 
BD-500-1A11 series airplanes.

Flight Envelope Protection--High-Speed Limiting

0
1. In addition to Sec.  25.143, the following requirements apply: 
Operation of the high-speed limiter during all routine and descent 
procedure flight must not impede normal attainment of speeds up to 
overspeed warning.

    Issued in Renton, Washington, on April 22, 2014.
Jeffrey E. Duven,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 2014-13243 Filed 6-5-14; 8:45 am]
BILLING CODE 4910-13-P


