DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2017-1175; Product Identifier 2017-NM-087-AD]
RIN 2120-AA64

Airworthiness Directives; Bombardier, Inc., Airplanes

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 all
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 a report that Belleville washers installed on the shimmy
damper of the main landing gear may fail due to fatigue. This proposed
AD would require revising the maintenance or inspection program, as
applicable, to incorporate a repetitive task specified in the
maintenance review board report. We are proposing this AD to address
the unsafe condition on these products.

DATES: We must receive comments on this proposed AD by February 16, 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 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, 1601 Lind Avenue SW, Renton, WA. For
information on the availability of this material at the FAA, call 425-
227-1221.

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-2017-1175;
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: Cesar Gomez, Aerospace Engineer,
Airframe and Mechanical Systems Section, FAA, New York ACO Branch, 1600
Stewart Avenue, Suite 410, Westbury, NY 11590; telephone 516-228-7318;
fax 516-794-5531.

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-2017-1175; Product Identifier 2017-NM-087
-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, which is the aviation authority
for Canada, has issued Canadian AD CF-2017-14, dated April 21, 2017
(referred to after this as the Mandatory Continuing Airworthiness
Information, or "the MCAI"), to correct an unsafe condition for all
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:

It has been found that Belleville washers installed on the Main
Landing Gear (MLG) Shimmy Damper may fail in fatigue. A failed
washer segment migrating into the piston cavity may interfere with
piston travel. As a result, shimmy damper performance would be
compromised, MLG shimmy could occur and potentially lead to a MLG
failure.

As a result of this investigation, a restoration task has been
added for Belleville washers' replacement at 20,000 flight cycles,
during MLG overhaul. For aeroplanes that have passed the 20,000
flight cycle threshold, a phase-in period is defined.

This [Canadian] AD is issued to mandate the Maintenance Review
Board (MRB) revised task for the affected aeroplanes models.

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-2017-1175.

Related Service Information Under 1 CFR Part 51

Bombardier, Inc., has issued task number 320100-229, Restoration
(Belleville Washing Replacement) of the MLG Shimmy Damper, of the
Maintenance Review Board Report of the Bombardier CRJ700/705/900/1000
Maintenance Requirements Manual (MRM)--Part 1, CSP B-053, Revision 17,
dated June 25, 2017. This service information describes the restoration
(Belleville Washer Replacement) of the MLG shimmy damper. 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) of this proposed AD.
The request should include a description of changes to the required
actions that will ensure the continued damage tolerance of the affected
structure.

Costs of Compliance

We estimate that this proposed AD affects 544 airplanes of U.S.
registry.

We estimate the following costs to comply with this proposed 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.

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):