DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2018-0274; Product Identifier 2017-NM-128-AD; Amendment
39-19325; AD 2018-14-05]
Airworthiness Directives; Bombardier, Inc., Airplanes
AGENCY: Federal Aviation Administration (FAA), Department of
ACTION: Final rule.
SUMMARY: We are adopting a new airworthiness directive (AD) for
Bombardier, Inc., Model BD-100-1A10 airplanes. This AD was prompted by
reports of fire incidents of the auxiliary power unit (APU) inlet,
which caused tail cone damage after an initial failed APU start
followed by two or more in-flight APU start attempts. This AD requires
modification of the APU electronic control unit (ECU) wiring harness.
We are issuing this AD to address the unsafe condition on these
DATES: This AD is effective August 13, 2018.
The Director of the Federal Register approved the incorporation by
reference of certain publications listed in this AD as of August 13,
ADDRESSES: For service information identified in this final rule,
contact Bombardier, Inc., 400 Cote-Vertu Road West, Dorval,
Quebec H4S 1Y9, Canada; telephone 514-855-5000; fax 514-855-
7401; email firstname.lastname@example.org; internet http://www.bombardier.
com. You may view this service information at the FAA,
Transport Standards Branch, 2200 South 216th St., Des Moines, WA. For
information on the availability of this material at the FAA, call 206-
231-3195. It is also available on the internet at http://www.regulations.gov
by searching for and locating Docket No. FAA-2018-0274.
Examining the AD Docket
You may examine the AD docket on the internet at http://www.regulations.gov
by searching for and locating Docket No. FAA-2018-
0274; or in person at Docket Operations between 9 a.m. and 5 p.m.,
Monday through Friday, except Federal holidays. The AD docket contains
this final rule, the regulatory evaluation, any comments received, and
other information. The address for Docket Operations (phone: 800-647-
5527) is in the ADDRESSES section. Comments will be available in the AD
docket shortly after receipt.
FOR FURTHER INFORMATION CONTACT: Assata Dessaline, Aerospace Engineer,
Avionics and Administrative Services Section, FAA, New York ACO Branch,
1600 Stewart Avenue, Suite 410, Westbury, NY 11590; telephone 516-228-
7301; fax 516-794-5531; email email@example.com.
We issued a notice of proposed rulemaking (NPRM) to amend 14 CFR
part 39 by adding an AD that would apply to certain Bombardier, Inc.,
Model BD-100-1A10 airplanes. The NPRM published in the Federal Register
on April 13, 2018 (83 FR 16013). The NPRM was prompted by reports of
fire incidents of the APU inlet, which caused tail cone damage after an
initial failed APU start followed by two or more in-flight APU start
attempts. The NPRM proposed to require modification of the APU ECU
We are issuing this AD to address failure of the APU inlet, which
could result in a fire during flight.
Transport Canada Civil Aviation (TCCA), which is the aviation
authority for Canada, has issued Canadian Airworthiness Directive CF-
2017-26, dated July 31, 2017, (referred to after this as the Mandatory
Continuing Airworthiness Information, or ``the MCAI''), to correct an
unsafe condition for certain Bombardier, Inc., Model BD-100-1A10
airplanes. The MCAI states:
APU inlet fire incidents causing tail cone damage have been
reported after an initial failed APU start followed by two or more
in-flight APU start attempts. Bombardier, Inc. (BA) has determined
that the in-flight negative pressure differential at the APU inlet
allows flash fires of residual fuel in the APU combustor to exit
through the APU inlet.
As an interim mitigating action, BA has revised the affected
aeroplane Aircraft Flight Manual (AFM) procedure for in-flight APU
start to limit the number of APU start attempts.
To further address the safety concerns associated with in-flight
APU inlet fire, BA is introducing a modification to the APU
Electronic Control Unit (ECU) wiring harness that will prevent a
second attempt to start the APU following a failed start in flight.
This [Canadian] AD is issued to mandate compliance with BA Service
Bulletin (SB) 100-49-04 or SB 350-49-001, as applicable, on affected
You may examine the MCAI in the AD docket on the internet at http://www.
regulations.gov by searching for and locating Docket No. FAA-2018-0274.
We gave the public the opportunity to participate in developing
this final rule. We received no comments on the NPRM or on the
determination of the cost to the public.
We reviewed the relevant data and determined that air safety and
the public interest require adopting this final rule as proposed,
except for minor editorial changes. We have determined that these minor
Are consistent with the intent that was proposed in the
NPRM for addressing the unsafe condition; and
Do not add any additional burden upon the public than was
already proposed in the NPRM.
Related Service Information Under 1 CFR Part 51
Bombardier has issued Service Bulletin 100-49-04, dated March 29,
2017; and Service Bulletin 350-49-001, dated March 29, 2017. This
service information describes a modification of the APU ECU harness.
These documents are distinct since they apply to different airplane
models in different configurations. This service information is
reasonably available because the interested parties have access to it
through their normal course of business or by the means identified in
the ADDRESSES section.
Costs of Compliance
We estimate that this AD affects 198 airplanes of U.S. registry.
We estimate the following costs to comply with this AD:
||Cost per product
||Cost on U.S. operators
||3 work-hours x $85 per hour =
Authority for This Rulemaking
Title 49 of the United States Code specifies the FAA's authority to
issue rules on aviation safety. Subtitle I, section 106, describes the
authority of the FAA Administrator. Subtitle VII: Aviation Programs,
describes in more detail the scope of the Agency's authority.
We are issuing this rulemaking under the authority described in
Subtitle VII, Part A, Subpart III, Section 44701: ``General
requirements.'' Under that section, Congress charges the FAA with
promoting safe flight of civil aircraft in air commerce by prescribing
regulations for practices, methods, and procedures the Administrator
finds necessary for safety in air commerce. This regulation is within
the scope of that authority because it addresses an unsafe condition
that is likely to exist or develop on products identified in this
This AD is issued in accordance with authority delegated by the
Executive Director, Aircraft Certification Service, as authorized by
FAA Order 8000.51C. In accordance with that order, issuance of ADs is
normally a function of the Compliance and Airworthiness Division, but
during this transition period, the Executive Director has delegated the
authority to issue ADs applicable to transport category airplanes and
associated appliances to the Director of the System Oversight Division.
This AD will not have federalism implications under Executive Order
13132. This AD will not have a substantial direct effect on the States,
on the relationship between the national government and the States, or
on the distribution of power and responsibilities among the various levels
For the reasons discussed above, I certify that this AD:
(1) Is not a ``significant regulatory action'' under Executive
(2) Is not a ``significant rule'' under the DOT Regulatory Policies
and Procedures (44 FR 11034, February 26, 1979),
(3) Will not affect intrastate aviation in Alaska, and
(4) Will not have a significant economic impact, positive or
negative, on a substantial number of small entities under the criteria
of the Regulatory Flexibility Act.
List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, Incorporation by
Adoption of the Amendment
Accordingly, under the authority delegated to me by the
Administrator, the FAA amends 14 CFR part 39 as follows:
PART 39--AIRWORTHINESS DIRECTIVES
1. The authority citation for part 39 continues to read as follows:
Authority: 49 U.S.C. 106(g), 40113, 44701.
Sec. 39.13 [Amended]
2. The FAA amends Sec. 39.13 by adding the following new airworthiness