DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2016-6148; Directorate Identifier 2015-NM-154-AD;
Amendment 39-18660; AD 2016-19-11]
RIN 2120-AA64

Airworthiness Directives; Bombardier, Inc. Airplanes

AGENCY: Federal Aviation Administration (FAA), Department of
Transportation (DOT).

ACTION: Final rule.

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SUMMARY: We are adopting a new airworthiness directive (AD) for certain
Bombardier, Inc. Model DHC-8-400 series airplanes. This AD was prompted
by a malfunctioning No. 2 engine intake heater with corrosion on the
thermostats and the fuselage skin where the thermostats made contact
with the aircraft fuselage skin. This AD requires a general visual
inspection for corrosion of the thermostats' mounting surfaces and
fuselage skin surface, corrective actions if necessary, and relocating
the existing thermostats. We are issuing this AD to prevent corrosion
within the thermostats that might cause the switch mechanism to seize
in the open position and prevent the activation of the associated
engine air intake heater. An inactive engine air intake heater could
lead to an engine failure.

DATES: This AD is effective November 2, 2016.
The Director of the Federal Register approved the incorporation by
reference of a certain publication listed in this AD as of November 2,
2016.

ADDRESSES: For service information identified in this final rule,
contact Bombardier, Inc., Q-Series Technical Help Desk, 123 Garratt
Boulevard, Toronto, Ontario M3K 1Y5, Canada; telephone: 416-375-4000;
fax: 416-375-4539; email: thd.qseries@aero.bombardier.com; Internet:
http://www.bombardier.com. You may view this referenced service
information at the FAA, Transport Airplane Directorate, 1601 Lind
Avenue SW., Renton, WA. For information on the availability of this
material at the FAA, call 425-227-1221. It is also available on the
Internet at http://www.regulations.gov by searching for and locating
Docket No. FAA-2016-6148.

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-2016-
6148; or in person at the Docket Management Facility between 9 a.m. and
5 p.m., Monday through Friday, except Federal holidays. The AD docket
contains this AD, the regulatory evaluation, any comments received, and
other information. The street address for the Docket Office (telephone
800-647-5527) is Docket Management Facility, U.S. Department of
Transportation, Docket Operations, M-30, West Building Ground Floor,
Room W12-140, 1200 New Jersey Avenue SE., Washington, DC 20590.

FOR FURTHER INFORMATION CONTACT: Assata Dessaline, Aerospace Engineer,
Avionics and Services Branch, ANE-172, FAA, New York Aircraft
Certification Office (ACO), 1600 Stewart Avenue, Suite 410, Westbury,
NY 11590; telephone 516-228-7301; fax 516-794-5531.

SUPPLEMENTARY INFORMATION:

Discussion

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 DHC-8-400 series airplanes. The NPRM published in the Federal
Register on May 2, 2016 (81 FR 26176) (``the NPRM'').
Transport Canada Civil Aviation (TCCA), which is the aviation
authority for Canada, has issued Canadian Airworthiness Directive CF-
2015-24, dated August 24, 2015 (referred to after this as the Mandatory
Continuing Airworthiness Information, or ``the MCAI''), to correct an
unsafe condition for certain Bombardier, Inc. Model DHC-8-400 series
airplanes. The MCAI states:

A malfunctioning Engine Air Intake Heater has been discovered
with corrosion on the thermostats and the aeroplane skin where the
thermostats are installed. The two thermostats are installed
directly under the flight compartment floor along the aeroplane
centre line where moisture accumulation and/or migration may occur,
which can cause corrosion of the thermostats. Corrosion within the
thermostats may seize the switch mechanism open, preventing the
activation of the associated Engine Air Intake Heater. Failure of
the Engine Air Intake Heater to activate may pose a safety risk to
the aeroplane in icing conditions.
Bombardier has issued Service Bulletin (SB) 84-30-10 to inspect,
replace if required and relocate the thermostat assembly to rectify
this problem. [An inactive engine air intake heater could lead to an
engine failure.]

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-2016-
6148.

Comments

We gave the public the opportunity to participate in developing
this AD. We received no comments on the NPRM or on the determination of
the cost to the public.

Conclusion

We reviewed the relevant data and determined that air safety and
the public interest require adopting this AD as proposed except for
minor editorial changes. We have determined that these minor changes:
Are consistent with the intent that was proposed in the
NPRM for correcting 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, Inc. has issued Bombardier Service Bulletin 84-30-10,
Revision E, dated October 10, 2014. The service information describes
procedures for a general visual inspection for corrosion of the
thermostats' mounting surfaces and fuselage skin surface, corrective
actions, and relocating the existing thermostats from a lower position
on the aircraft skin at X 54.00 between stringers 31P and 32P (next to
the centerline) to a higher position at X 54.00 between stringers 26P
and 27P. 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 76 airplanes of U.S. registry.
We estimate the following costs to comply with this AD:

Estimated Costs

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
rulemaking action.

Regulatory Findings

We determined that 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 of government.
For the reasons discussed above, I certify that this AD:
1. Is not a ``significant regulatory action'' under Executive Order
12866;
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
reference, Safety.

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
directive (AD):