DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2018-0551; Product Identifier 2018-NM-023-AD]
RIN 2120-AA64

Airworthiness Directives; Bombardier, Inc.

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: We propose to adopt 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 proposed
AD was prompted by reports of damage to the protective coating and
corrosion on the piston/axle of the main landing gear (MLG), caused by
friction between the inboard axle sleeve and the axle thrust face. This
proposed AD would require revising the maintenance or inspection
program, as applicable, to incorporate a detailed inspection of the MLG
piston/axle for damage to the protective coating and for corrosion. We
are proposing this AD to address the unsafe condition on these
products.

DATES: We must receive comments on this proposed AD by August 20, 2018.

ADDRESSES: You may send comments, using the procedures found in 14 CFR
11.43 and 11.45, by any of the following methods:

Federal eRulemaking Portal: Go to http://www.regulations.gov. Follow the
instructions for submitting comments.

Fax: 202-493-2251.

Mail: U.S. Department of Transportation, Docket
Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New
Jersey Avenue SE, Washington, DC 20590.

Hand Delivery: Deliver to Mail address above between 9
a.m. and 5 p.m., Monday through Friday, except Federal holidays.

For service information identified in this NPRM, contact
Bombardier, Inc., 400 C[ocirc]te-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.

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-2018-0551; 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 NPRM, the regulatory evaluation, any comments received,
and other information. The street address for the Docket Operations
office (telephone 800-647-5527) is in the ADDRESSES section. Comments
will be available in the AD docket shortly after receipt.

FOR FURTHER INFORMATION CONTACT: Darren Gassetto, Aerospace Engineer,
Airframe and Mechanical Systems Section, FAA, New York ACO Branch, 1600
Stewart Avenue, Suite 410, Westbury, NY 11590; telephone 516-228-7323;
fax 516-794-5531; email 9-avs-nyaco-cos@faa.gov.

SUPPLEMENTARY INFORMATION:

Comments Invited

We invite you to send any written relevant data, views, or
arguments about this proposal. Send your comments to an address listed
under the ADDRESSES section. Include "Docket No. FAA-2018-0551;
Product Identifier 2018-NM-023-AD'' at the beginning of your comments.
We specifically invite comments on the overall regulatory, economic,
environmental, and energy aspects of this NPRM. We will consider all
comments received by the closing date and may amend this NPRM based on
those comments.

We will post all comments we receive, without change, to
http://www.regulations.gov, including any personal information you provide. We
will also post a report summarizing each substantive verbal contact we
receive about this NPRM.

Discussion

Transport Canada Civil Aviation (TCCA), which is the aviation
authority for Canada, has issued Canadian AD CF-2017-38, dated December
20, 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 reports of damage to the protective coating and/
or corrosion on the piston/axle of the Main Landing Gear (MLG). The
damage to the protective coating was caused by friction between the
inboard axle sleeve and the axle thrust face. If not corrected, this
condition can cause the axle to separate from the piston/axle [and
consequent collapse of the landing gear during ground maneuvers or
upon landing].

This [Canadian] AD mandates the incorporation of a new
maintenance task in order to perform a [detailed] visual inspection
of the piston/axle of the MLG to prevent the axle separation from
the piston/axle.

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-2018-0551.

Related Service Information Under 1 CFR Part 51

Bombardier, Inc. has issued CRJ Series Regional Jet Temporary
Revision (TR) MRB-0059, dated March 20, 2015, to Bombardier CRJ Series
Regional Jet Maintenance Requirements Manual (MRM), Part 1, CSP B-053.
The service information describes an airworthiness limitation task for
a detailed inspection for damage to the protective coating and for
corrosion on the piston/axle of the MLG. 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.

FAA's Determination and Requirements of This Proposed AD

This product has been approved by the aviation authority of another
country, and is approved for operation in the United States. Pursuant
to our bilateral agreement with the State of Design Authority, we have
been notified of the unsafe condition described in the MCAI and service
information referenced above. We are proposing this AD because we
evaluated all pertinent information and determined an unsafe condition
exists and is likely to exist or develop on other products of the same
type design.

This AD requires revisions to certain operator maintenance
documents to include new actions (e.g., inspections). Compliance with
these actions is required by 14 CFR 91.403(c). For airplanes that have
been previously modified, altered, or repaired in the areas addressed
by this proposed AD, the operator may not be able to accomplish the
actions described in the revisions. In this situation, to comply with
14 CFR 91.403(c), the operator must request approval for an alternative
method of compliance according to paragraph (j)(1) of this proposed AD.
The request should include a description of changes to the required
inspections that will ensure the continued operational safety of the
airplane.

Costs of Compliance

We estimate that this proposed AD affects 530 airplanes of U.S.
registry. We estimate the following costs to comply with this proposed AD:

We have determined that revising the maintenance or inspection
program takes an average of 90 work-hours per operator, although we
recognize that this number may vary from operator to operator. In the
past, we have estimated that this action takes 1 work-hour per
airplane. Since operators incorporate maintenance or inspection program
changes for their affected fleet(s), we have determined that a per-
operator estimate is more accurate than a per-airplane estimate.
Therefore, we estimate the total cost per operator to be $7,650 (90
work-hours x $85 per work-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
rulemaking action.

This proposed 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 proposed AD would not have federalism
implications under Executive Order 13132. This proposed AD would 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 this proposed regulation:

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.

The Proposed Amendment

Accordingly, under the authority delegated to me by the
Administrator, the FAA proposes to amend 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):