DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2017-0712; Product Identifier 2017-NM-014-AD;
Amendment 39-19095; AD 2017-23-01]
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 superseding Airworthiness Directive (AD) 2016-13-14,
which applied to certain Bombardier, Inc., Model DHC-8-400 series
airplanes. AD 2016-13-14 required an inspection to determine if certain
left and right main landing gear (MLG) retract actuator rod ends were
installed, repetitive liquid penetrant inspections (LPIs) of affected
left and right MLG retract actuator rod ends, and corrective actions if
necessary. This new AD retains the actions specified in AD 2016-13-14
and also requires replacement of the left and right MLG retract
actuator rod ends. This AD was prompted by a report of a cracked MLG
retract actuator rod end. We are issuing this AD to address the unsafe
condition on these products.

DATES: This AD is effective December 19, 2017.
The Director of the Federal Register approved the incorporation by
reference of a certain publication listed in this AD as of July 20,
2016 (81 FR 43481, July 5, 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 Standards Branch, 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-2017-0712.

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-2017-
0712; 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 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: Aziz Ahmed, Aerospace Engineer,
Airframe and Mechanical Systems Section, FAA, New York ACO Branch, 1600
Stewart Avenue, Suite 410, Westbury, NY 11590; telephone: 516-228-7329;
fax: 516-794-5531.

SUPPLEMENTARY INFORMATION:

Discussion

We issued a notice of proposed rulemaking (NPRM) to amend 14 CFR
part 39 to supersede AD 2016-13-14, Amendment 39-18579 (81 FR 43481,
July 5, 2016) (``AD 2016-13-14''). AD 2016-13-14 applied to certain
Bombardier, Inc., Model DHC-8-400 series airplanes. The NPRM published
in the Federal Register on July 28, 2017
(82 FR 35127). The NPRM was prompted by a report of a cracked MLG
retract actuator rod end. The NPRM proposed to continue to require the
actions specified in AD 2016-13-14. The NPRM also proposed to require
replacement of the left and right MLG retract actuator rod ends. We are
issuing this AD to detect and correct fatigue cracking of the left and
right MLG retract actuator rod ends, which could lead to left or right
MLG collapse.
Transport Canada Civil Aviation (TCCA), which is the aviation
authority for Canada, has issued Canadian AD CF-2016-16R1, dated June
27, 2016 (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:

There has been a single reported case of a cracked MLG retract
actuator rod end in service. A supplier disclosure letter and
subsequent Bombardier analysis indicate that the MLG retract
actuator rod end P/N [part number] P3A2750 and P3A2750-1 may develop
fatigue cracking. This condition, if not corrected, could lead to
left hand (LH) or right hand (RH) MLG collapse.
This [Canadian] AD mandates the inspection [to determine if
certain left and right main landing gear MLG retract actuator rod
ends are installed, repetitive LPIs of affected left and right MLG
retract actuator rod ends, and corrective actions if necessary], and
replacement of the LH and RH MLG retract actuator rod ends P/N
P3A2750 and P3A2750-1 [which is terminating action for the
repetitive LPIs].
This [Canadian] AD was revised to clarify paragraph B. and C.
[of this Canadian AD], which specifies when the Liquid Penetrant
Inspections (LPI) should begin.

Corrective actions include replacing cracked MLG retract actuator
rod ends. 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-2017-0712.

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 available 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 84-32-142,
dated May 4, 2016. This service information describes procedures for an
inspection to determine if certain left and right MLG retract actuator
rod ends are installed, repetitive LPIs of the left and right MLG
retract actuator rod ends, and replacement of left and right MLG
retract actuator rod ends. 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 52 airplanes of U.S. registry.
We estimate the following costs to comply with this AD:
The actions required by AD 2016-13-14, and retained in this AD,
take about 1 work-hour per product, at an average labor rate of $85 per
work-hour. Based on these figures, the estimated cost of the inspection
that is required by AD 2016-13-14 is $85 per product.
We also estimate that it will take about 3 work-hours per product
to comply with the basic requirements of this AD. The average labor
rate is $85 per work-hour. Required parts will cost about $2,019 per
product. Based on these figures, we estimate the cost of this AD on
U.S. operators to be $118,248, or $2,274 per product.
In addition, we estimate that any necessary follow-on actions will
take about 3 work-hours and require parts costing $2,019, for a cost of
$2,274 per product. We have no way of determining the number of
aircraft that might need these actions.
According to the manufacturer, some of the costs of this AD may be
covered under warranty, thereby reducing the cost impact on affected
individuals. We do not control warranty coverage for affected
individuals. As a result, we have included all available costs in our
cost estimate.

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.
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 to
the Director of the System Oversight Division.

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 removing Airworthiness Directive (AD)
2016-13-14, Amendment 39-18579 (81 FR 43481, July 5, 2016), and adding
the following new AD: