Document ID: FAA-2017-0033-0001
Agency: faa
Document Type: Rule
Title: Special Conditions: Bombardier Aerospace, Model BD-700-2A12 and BD-700-2A13 Airplanes; Limit Engine Torque Loads
Posted Date: 2017-05-12T04:00Z

[Federal Register Volume 82, Number 91 (Friday, May 12, 2017)]
[Rules and Regulations]
[Pages 22065-22066]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2017-09663]

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 Rules and Regulations
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  Federal Register / Vol. 82, No. 91 / Friday, May 12, 2017 / Rules and 
Regulations  

[[Page 22065]]

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 25

[Docket No. FAA-2017-0033; Special Conditions No. 25-670-SC]

Special Conditions: Bombardier Aerospace, Model BD-700-2A12 and 
BD-700-2A13 Airplanes; Limit Engine Torque Loads

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final special conditions; request for comments.

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SUMMARY: These special conditions are issued for the Bombardier 
(Bombardier) Inc. Models BD-700-2A12 and BD-700-2A13 airplanes. This 
airplane will have a novel or unusual design feature when compared to 
the state of technology envisioned in the airworthiness standards for 
transport-category airplanes. This design feature is the engine torque-
load limit imposed by sudden engine stoppage due to malfunction or 
structural failure. 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: This action is effective on Bombardier on May 12, 2017. Send 
your comments on or before June 26, 2017.

ADDRESSES: Send comments identified by docket number FAA-2017-0033 
using any of the following methods:
     Federal eRegulations Portal: Go to http://www.regulations.gov/ and follow the online instructions for sending 
your comments electronically.
     Mail: Send comments to Docket Operations, M-30, U.S. 
Department of Transportation (DOT), 1200 New Jersey Avenue SE., Room 
W12-140, West Building Ground Floor, Washington, DC 20590-0001.
     Hand Delivery or Courier: Take comments to Docket 
Operations in Room W12-140 of the West Building Ground Floor at 1200 
New Jersey Avenue SE., Washington, DC, between 8 a.m. and 5 p.m., 
Monday through Friday, except federal holidays.
     Fax: Fax comments to Docket Operations at 202-493-2251.
    Privacy: The FAA will post all comments it receives, without 
change, to http://www.regulations.gov/, including any personal 
information the commenter provides. Using the search function of the 
docket Web site, anyone can find and read the electronic form of all 
comments received into any FAA docket, including the name of the 
individual sending the comment (or signing the comment for an 
association, business, labor union, etc.). DOT's complete Privacy Act 
Statement can be found in the Federal Register published on April 11, 
2000 (65 FR 19477-19478).
    Docket: Background documents or comments received may be read at 
http://www.regulations.gov/ at any time. Follow the online instructions 
for accessing the docket or go to the Docket Operations in Room W12-140 
of the West Building Ground Floor at 1200 New Jersey Avenue SE., 
Washington, DC, between 9 a.m. and 5 p.m., Monday through Friday, 
except federal holidays.

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: The substance of these special conditions 
has been subject to the public notice and comment period in several 
prior instances, and has been derived without substantive change from 
those previously issued. It is unlikely that prior public comment would 
result in a significant change from the substance contained herein. 
Therefore, the FAA has determined that prior public notice and comment 
are unnecessary and impracticable, and good cause exists for adopting 
these special conditions upon issuance. The FAA is requesting comments 
to allow interested persons to submit views that may not have been 
submitted in response to the prior opportunities for comment described 
above. It is further unnecessary to delay the effective date for the 
reasons previously stated.

Comments Invited

    We invite interested people to take part in this rulemaking by 
sending written comments, data, or views. The most helpful comments 
reference a specific portion of the special conditions, explain the 
reason for any recommended change, and include supporting data.
    We will consider all comments we receive on or before the closing 
date for comments. We may change these special conditions based on the 
comments we receive.

Background

    On May 30, 2012, Bombardier applied for an amendment to Type 
Certificate No. T00003NY to include the new Model BD-700-2A12 and BD-
700-2A13 airplanes. These airplanes are derivatives of the Model BD-700 
series of airplanes and are marketed as the Bombardier Global 7000 
(Model BD-700-2A12) and Global 8000 (Model BD-700-2A13). These 
airplanes are twin-engine, transport-category, executive-interior 
business jets. The maximum passenger capacity is 19 and the maximum 
takeoff weights are 106,250 lbs. (Model BD-700-2A12) and 104,800 lbs. 
(Model BD-700-2A13).

Type Certification Basis

    Under the provisions of Title 14, Code of Federal Regulations (14 
CFR) 21.101, Bombardier must show that the Model BD-700-2A12 and BD-
700-2A13 airplanes meet the applicable provisions of the regulations 
listed in Type Certificate No. T00003NY, or the applicable regulations 
in effect on the date of application for the change, except for earlier 
amendments as agreed upon by the FAA.
    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 Model BD-700-2A12 and BD-700-2A13 
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

[[Page 22066]]

include any other model that incorporates the same novel or unusual 
design feature, or should any other model already included on the same 
type certificate be modified to incorporate the same novel or unusual 
design feature, these special conditions would also apply to the other 
model under Sec.  21.101.
    In addition to the applicable airworthiness regulations and special 
conditions, the Model BD-700-2A12 and BD-700-2A13 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.
    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.  21.101.

Novel or Unusual Design Feature

    The Bombardier Model BD-700-2A12 and BD-700-2A13 airplanes will 
incorporate a novel or unusual design feature associated with engine-
seizure requirements due, in part, to large bypass fans capable of 
producing much larger and more complex dynamic loads than would other 
bypass fans.

Discussion

    The limit engine torque load imposed by sudden engine stoppage due 
to malfunction or structural failure (such as compressor jamming) has 
been a specific requirement for transport-category airplanes since 
1957. In the past, the design torque loads associated with typical 
failure scenarios have been estimated by the engine manufacturer and 
provided to the airframe manufacturer as limit loads. These limit loads 
were considered simple, pure, torque static loads.
    It is evident from service history that the engine-failure events 
that tend to cause the most severe loads are fan-blade failures. These 
events occur much less frequently than the typical ``limit'' load 
condition.
    Regulatory authorities and industry have developed a standardized 
requirement in the Aviation Rulemaking Advisory Committee (ARAC) forum 
(Aviation Rulemaking Advisory Committee; Loads and Dynamics 
Harmonization Working Group [58 FR 13819]). The technical aspects of 
this requirement have been agreed upon, and the ARAC Loads and Dynamics 
Harmonization Working Group has accepted them. These special conditions 
reflect the ARAC recommendation. The ARAC recommendation includes 
corresponding advisory material, which is considered an acceptable 
means of compliance to these special conditions.
    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.

Applicability

    As discussed above, these special conditions are applicable to the 
Model BD-700-2A12 and BD-700-2A13 airplanes. Should Bombardier apply at 
a later date for a change to the type certificate to include another 
model incorporating the same novel or unusual design feature, these 
special conditions would apply to the other model as well.

Conclusion

    This action affects only one novel or unusual design feature on 
Bombardier Model BD-700-2A12 and BD-700-2A13 airplanes. It is not a 
rule of general applicability and affects only the applicant who 
applied to FAA for approval of this feature on the airplane.

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 Proposed 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 Bombardier Model BD-700-2A12 and BD-
700-2A13 airplanes.
    In lieu of Sec.  25.361(b) the following special conditions apply:
    1. For turbine engine installations, the engine mounts, pylons, and 
adjacent supporting airframe structure must be designed to withstand 1g 
level flight loads acting simultaneously with the maximum limit torque 
loads imposed by each of the following:
    a. Sudden engine deceleration due to a malfunction that could 
result in a temporary loss of power or thrust, and
    b. The maximum acceleration of the engine.
    2. For auxiliary power unit (APU) installations, the power unit 
mounts and adjacent supporting airframe structure must be designed to 
withstand 1g level flight loads acting simultaneously with the maximum 
limit torque loads imposed by each of the following:
    a. Sudden APU deceleration due to malfunction or structural 
failure; and
    b. The maximum acceleration of the APU.
    3. For engine supporting structure, an ultimate loading condition 
must be considered that combines 1g flight loads with the transient 
dynamic loads resulting from:
    a. The loss of any fan, compressor, or turbine blade; and 
separately
    b. Where applicable to a specific engine design, any other engine 
structural failure that results in higher loads.
    4. The ultimate loads developed from the conditions specified in 
paragraphs 3(a) and 3(b) of these special conditions are to be 
multiplied by a factor of 1.0 when applied to engine mounts and pylons, 
and multiplied by a factor of 1.25 when applied to adjacent supporting 
airframe structure.
    5. Any permanent deformation that results from the conditions 
specified in paragraph 3 must not prevent continued safe flight and 
landing.

    Issued in Renton, Washington, on April 27, 2017.
Paul Bernado,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 2017-09663 Filed 5-11-17; 8:45 am]
 BILLING CODE 4910-13-P