DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2016-9438; Directorate Identifier 2016-NM-109-AD;
Amendment 39-18873; AD 2017-09-11]
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 reports of interruptions in the airstair door operation. This AD
requires repetitive inspections and modification of the handrail
hardware. We are issuing this AD to address the unsafe condition on
these products.

DATES: This AD is effective June 29, 2017.
The Director of the Federal Register approved the incorporation by
reference of a certain publication listed in this AD as of June 29,
2017.

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-2016-9438.

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-
9438; 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: Cesar A. Gomez, Aerospace Engineer,
Airframe and Mechanical Systems Branch, ANE-171, FAA, New York Aircraft
Certification Office (ACO), 1600 Stewart Avenue, Suite 410, Westbury,
NY 11590; telephone 516-228-7318; 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 December 16, 2016 (81 FR 91058) (``the NPRM''). The NPRM
was prompted by reports of interruptions in the airstair door
operation. The NPRM proposed to require repetitive inspections and
modification of the handrail hardware. We are issuing this AD to ensure
the ability to evacuate passengers through the airstair door in the
event of an emergency.
Transport Canada Civil Aviation (TCCA), which is the aviation
authority for Canada, has issued Canadian Airworthiness Directive CF-
2015-02, dated January 27, 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, -401, and -402 airplanes. The MCAI states:

A number of airstair door operation interruptions have been
reported. In one case, the airstair door could not be opened. It was
found that the airstair door handrail holder bracket was deformed
and became lodged into the adjacent wardrobe bulkhead, which
prevented the door from opening.
On airstair doors with Jetway Compatible option, a deformed
handrail holder bracket or a failure of the pin retainer bracket can
interfere with the operation of the airstair door and prevent it
from opening.
The airstair door is classified as an emergency exit. The
inability to open an emergency exit could impede evacuation in the
event of an emergency.
This [Canadian] AD mandates the repetitive inspection of
airstair door handrail hardware, and the modification of the
handrail stowage hardware.

Required actions include applicable corrective actions (replacing
or removing brackets, installing lanyards, adjusting pins, and
adjusting affected parts of the assembly). 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-2016-9438.

Comments

We gave the public the opportunity to participate in developing
this AD. We considered the comment received. The Air Line Pilots
Association, International supported the NPRM.

Conclusion

We reviewed the relevant data, considered the comment received, 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. issued Service Bulletin 84-52-79, Revision C,
dated February 2, 2016. This service information describes procedures
for a general visual inspection to detect deformities and cracks of the
forward and aft handle holder brackets on the airstair handrail; a
detailed visual inspection of the forward and aft pin retainer brackets
for the condition of the lanyards and the pins; a check for
unobstructed movement of the pin retainer brackets; and rework of the
airstair door handrail to prevent damage to the bulkhead and to prevent
the door from jamming once the handrails are stowed. 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 82 airplanes of U.S. registry.
We estimate the following costs to comply with this AD:

Estimated Costs

We have received no definitive data that will enable us to provide
cost estimates for the on-condition actions specified in this AD.

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):