DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2018-0275; Product Identifier 2018-NM-011-AD; Amendment
39-19323; AD 2018-14-03]
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 CL-600-2C10 (Regional Jet Series 700, 701, &
702) airplanes; Model CL-600-2D15 (Regional Jet Series 705) airplanes;
Model CL-600-2D24 (Regional Jet Series 900) airplanes; and Model CL-
600-2E25 (Regional Jet Series 1000) airplanes. This AD was prompted by
reports indicating that corrosion was found on the main landing gear
(MLG) retraction actuator brackets and their associated pins. This AD
requires an inspection of the retraction actuator brackets, their
associated pins and hardware, and the mating lugs on the MLG outer
cylinder for any corrosion, and replacement if necessary. We are
issuing this AD to address the unsafe condition on these products.

DATES: This AD is effective August 13, 2018.
The Director of the Federal Register approved the incorporation by
reference of a certain publication listed in this AD as of August 13,
2018.

ADDRESSES: For service information identified in this final rule,
contact Bombardier, Inc., 400 Cote-Vertu Road West, Dorval,
Quebec H4S 1Y9, Canada; Widebody Customer Response Center North
America toll-free telephone 1-866-538-1247 or direct-dial telephone 1-
514-855-2999; fax 514-855-7401; email ac.yul@aero.bombardier.com;
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-2018-0275.

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-
0275; 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: 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 an NPRM to amend 14 CFR part 39 by adding an AD that
would apply to certain Bombardier, Inc., Model CL-600-2C10 (Regional
Jet Series 700, 701, & 702) airplanes; Model CL-600-2D15 (Regional Jet
Series 705) airplanes; Model CL-600-2D24 (Regional Jet Series 900)
airplanes; and Model CL-600-2E25 (Regional Jet Series 1000) airplanes.
The NPRM published in the Federal Register on April 13, 2018 (83 FR
16015). The NPRM was prompted by reports indicating that corrosion was
found on the MLG retraction actuator brackets and their associated
pins. The NPRM proposed to require inspection of the retraction
actuator brackets, their associated pins and hardware, and the mating
lugs on the MLG outer cylinder for any corrosion, and replacement if
necessary.
We are issuing this AD to address undetected corrosion on the MLG
retraction actuator brackets and their associated pins, which could
lead to a MLG collapse.
Transport Canada Civil Aviation (TCCA), which is the aviation
authority for Canada, has issued Canadian AD CF-2017-34, dated October
19, 2017 (referred to after this as the Mandatory Continuing
Airworthiness Information, or ``the MCAI''), to correct an unsafe
condition for certain Bombardier, Inc., Model CL-600-2C10 (Regional Jet
Series 700, 701, & 702) airplanes; Model CL-600-2D15 (Regional Jet
Series 705) airplanes; Model CL-600-2D24 (Regional Jet Series 900)
airplanes; and Model CL-600-2E25 (Regional Jet Series 1000) airplanes.
The MCAI states:

There have been in-service reports of corrosion on the main
landing gear (MLG) retraction actuator bracket and its associated
pins. Bombardier's investigation determined that the corrosion is
the consequence of inadequate corrosion protection being applied
during production. Undetected corrosion on the MLG retraction
actuator bracket and its associated pins could result in a MLG
collapse.
This [Canadian] AD mandates the inspection of the MLG retraction
actuator bracket, its associated pins and hardware, and the mating
lugs on the MLG outer cylinder for corrosion. This [Canadian] AD
also mandates the replacement of corroded MLG parts and the
application of corrosion protection in order to mitigate the risk of
MLG collapse.

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-
0275.

Comments

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.

Conclusion

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
changes:
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 670BA-32-060, Revision B,
dated November 10, 2017. The service information describes a detailed
visual inspection of the retraction actuator brackets, their associated
pins and hardware, and the mating lugs on the MLG outer cylinder for
any corrosion, and replacement if necessary. 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 541 airplanes of U.S. registry.
We estimate the following costs to comply with this AD:

Estimated Costs

We estimate the following costs to do any necessary replacements
that would be required based on the results of the inspection. We have
no way of determining the number of aircraft that might need these
replacements:

On-Condition 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.
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.

Regulatory Findings

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):