Document ID: FAA-2013-0942-0002
Agency: faa
Document Type: Rule
Title: Special Conditions: Bombardier Aerospace Inc., Models BD-500-1A10 and BD-500-1A11 series airplanes; Autobraking System Loads
Posted Date: 2014-02-07T05:00Z

[Federal Register Volume 79, Number 26 (Friday, February 7, 2014)]
[Rules and Regulations]
[Pages 7370-7371]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2014-02613]

=======================================================================
-----------------------------------------------------------------------

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 25

[Docket No. FAA-2013-0942; Special Conditions No. 25-515-SC]

Special Conditions: Bombardier Aerospace Inc., Models BD-500-1A10 
and BD-500-1A11 Series Airplanes; Autobraking System Loads

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final special conditions.

-----------------------------------------------------------------------

SUMMARY: These special conditions are issued for the Bombardier 
Aerospace Inc. Models BD-500-1A10 and BD-500-1A11 series airplanes. 
These airplanes will have novel or unusual design features associated 
with the autobraking system for use during landing. 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

[[Page 7371]]

equivalent to that established by the existing airworthiness standards.

DATES: Effective Date: March 10, 2014.

FOR FURTHER INFORMATION CONTACT: Mark Freisthler, FAA, Airframe and 
Cabin Safety Branch, ANM-115 Transport Airplane Directorate, Aircraft 
Certification Service, 1601 Lind Avenue SW., Renton, Washington 98057-
3356; telephone 425-227-1119; 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-500-1A1 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.

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.
    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 section 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 C-series airplanes will incorporate the following novel or 
unusual design features: The C-series airplanes will have an autobrake 
system. This is a pilot-selectable function that allows earlier maximum 
braking at landing without pilot pedal input. When the autobrake system 
is armed before landing, it automatically commands maximum braking at 
main wheels touchdown. Normal procedures remain unchanged and call for 
manual braking after nose wheel touchdown.

Discussion

    Section 25.493 addresses braked roll loads but does not contain a 
specific ``pitchover'' requirement addressing the loading on the nose 
gear, the nose gear surrounding structure, and the forward fuselage. 
Moreover, Sec.  25.493 specifies airplane attitudes in accordance with 
figure 6 of appendix A to part 25, which are level landing attitudes. 
For airplanes with traditional braking systems, the current ground load 
requirements are considered adequate for the design of the nose gear 
and airframe structure. However, the C-Series airplane autobrake 
system, which could apply maximum braking at the main wheels with the 
airplane in a tail-down attitude well before the nose touches down, 
will cause a high nose gear sink rate and potentially higher gear and 
airframe loads.
    Part 25 does not contain adequate requirements to address the 
potentially higher structural loads that could result from this type of 
braking system. In addition, the effects on fatigue covered by Sec.  
25.571 also need to be considered. Therefore, FAA has determined that 
additional airworthiness standards are needed for the certification of 
this unusual design feature. These special conditions propose 
airworthiness standards for the certification of the C-series airplanes 
with an autobrake system.

Discussion of Comments

    Notice of proposed special conditions No. FAA-2013-0942 for the 
Bombardier C-series airplanes was published in the Federal Register on 
November 12, 2013 (78 FR 67321). 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 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 one 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 series airplanes.
    Autobraking System Loads. A landing pitchover condition must be 
addressed that takes into account the effect of the autobrake system. 
The airplane is assumed to be at the design maximum landing weight, or 
at the maximum weight allowed with the autobrake system on. The 
airplane is assumed to land in a tail-down attitude at the speeds 
defined by Sec.  25.481. Following main gear contact, the airplane is 
assumed to rotate about the main gear wheels at the highest pitch rate 
generated by the autobrake system. This is considered a limit load 
condition from which ultimate loads must also be determined. Loads must 
be determined for a critical fuel and payload distribution and centers 
of gravity. Nose gear loads, as well as airframe loads, must be 
determined. The airplane must support these loads as described in Sec.  
25.305.
    In addition to the above airworthiness standards, fatigue loads 
must also be determined and applied in accordance to Sec.  25.571.

    Issued in Renton, Washington, on January 31, 2014.
John P. Piccola, Jr.,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 2014-02613 Filed 2-6-14; 8:45 am]
BILLING CODE 4910-13-P