DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2019-0185; Product Identifier 2018-NM-178-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), CL-600-2D15 (Regional Jet Series 705), and CL-600-2D24 (Regional
Jet Series 900) airplanes. This proposed AD was prompted by a
determination that new or more restrictive airworthiness limitations
are necessary for operational checks of the landing gear alternate
extension system (AES). This proposed AD would require revising the
existing maintenance or inspection program, as applicable, to
incorporate new and more restrictive airworthiness limitations. We are
proposing this AD to address the unsafe condition on these products.

DATES: We must receive comments on this proposed AD by May 13, 2019.

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, 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-2019-0185;
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 NPRM, the regulatory evaluation, any comments received, and other
information. The street 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: Darren Gassetto, Aerospace Engineer,
Mechanical Systems and Administrative Services 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-2019-0185;
Product Identifier 2018-NM-178-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 because
of 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-2018-31, dated November
28, 2018 (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), CL-600-2D15 (Regional Jet Series 705), and CL-
600-2D24 (Regional Jet Series 900) airplanes. The MCAI states:

During the Bombardier Maintenance Review Board (MRB) inspection
escalation interval project, it was discovered that the current
interval of 8000 hours air time and previous interval of 6000 hours
air time for the MRB Task 320100-203 "Operational Check of the
Landing Gear Alternate Extension System (AES)" does not meet the
certification criteria to cover for all critical AES failure modes
[which could reduce the ability of the flightcrew to maintain the
safe flight and landing of the airplane]. For this reason, a new
Certification Maintenance Requirement (CMR) task needs to be
implemented in the maintenance program at a shorter interval of 1600
hours air time.

This [Canadian] AD mandates a new CMR task for an operational
check of the AES with interval of 1600 hours air time.

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-2019-
0185.

Related Service Information Under 1 CFR Part 51

Bombardier has issued Temporary Revision (TR) ALI-0652, dated July
9, 2018. This service information describes airworthiness limitations
for a CMR task related to operational checks of the landing gear AES.
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

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 the relevant information and determined the
unsafe condition described previously is likely to exist or develop on
other products of the same type design.

Proposed Requirements of This NPRM

This proposed AD would require revising the existing maintenance or
inspection program, as applicable, to incorporate new or more
restrictive airworthiness limitations.

This proposed AD would require 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
(i)(1) of this proposed AD.

Costs of Compliance

We estimate that this proposed AD affects 536 airplanes of U.S.
registry. We estimate the following costs to comply with this proposed
AD:

We have determined that revising the existing 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 and associated appliances 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):