DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2018-0399; Product Identifier 2018-NM-008-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 supersede Airworthiness Directive (AD) 2015-17-
04, which applies to certain Bombardier, Inc., Model CL-600-2C10
(Regional Jet Series 700, 701, & 702), Model CL-600-2D15 (Regional Jet
Series 705), and Model CL-600-2D24 (Regional Jet Series 900) airplanes.
AD 2015-17-04 requires replacement of left and right fixed control rods
and lever assemblies of the elevator control system. Since we issued AD
2015-17-04, we have received a report indicating that certain revisions
of the service information were missing instructions. This proposed AD
would require a detailed visual inspection of the key washers and self-
locking nuts of the elevator control linkages and corrective actions if
necessary. We are proposing this AD to address the unsafe condition on
these products.

DATES: We must receive comments on this proposed AD by June 25, 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 referenced 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-
0399; 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-2018-0399;
Product Identifier 2018-NM-008-AD" at the beginning of your comments.
We specifically invite comments on the overall regulatory, economic,
environmental, and energy aspects of this proposed AD. We will consider
all comments received by the closing date and may amend this proposed
AD 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 proposed AD.

Discussion

We issued AD 2015-17-04, Amendment 39-18237 (80 FR 50556, August
20, 2015) ("AD 2015-17-04"), for certain Bombardier, Inc., Model CL-
600-2C10 (Regional Jet Series 700, 701, & 702), Model CL-600-2D15
(Regional Jet Series 705), and Model CL-600-2D24 (Regional Jet Series
900) airplanes. AD 2015-17-04 requires replacement of left and right
fixed control rods and lever assemblies of the elevator control system.
AD 2015-17-04 resulted from reports of a disconnect between the
elevator lever and control rod. We issued AD 2015-17-04 to prevent a
disconnect between the elevator lever and control rod, which could lead
to uncommanded elevator movement of the associated control surface, a
large difference between the position of the left and the right
elevator control surfaces, and consequent reduced controllability of
the airplane and degradation of the structural integrity of the
horizontal stabilizer.

Actions Since AD 2015-17-04 Was Issued

Since we issued AD 2015-17-04, we have received a report indicating
that certain revisions of the service information were missing
instructions for proper installation of the key washers part number
BA698-93726-3.

Transport Canada Civil Aviation (TCCA), which is the aviation
authority for Canada, has issued Canadian AD CF-2014-44R1, dated
October 6, 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), Model CL-600-2D15 (Regional Jet Series 705),
and Model CL-600-2D24 (Regional Jet Series 900) airplanes. The MCAI
states:

During an engineering review of the Elevator Control system, it
was discovered that a disconnect between the elevator lever and
control rod could lead to an uncommanded elevator movement of the
associated control surface. This uncommanded movement may cause a
large difference between the position of the left and the right
elevator control surface resulting in reduced controllability of the
aeroplane and compromised structural integrity of the horizontal
stabilizer.

This [Canadian] AD mandates the replacement of the existing
elevator lever assemblies and control rods with newly designed ones,
which will prevent a disconnect between the components of the
elevator control system should a failure occur.

Revision 1 of this [Canadian] AD is issued to require operators,
* * * [regardless of previously accomplished actions], to perform
a detailed visual inspection for the correct installation of the tab
key washers and to re-torque the nut(s) [and corrective actions that
include bending one tab of the key washer on a flat surface of the
self-locking nut] if the tab key washer(s) does not have one tab
bent on a flat surface of the self-locking nut.

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-
0399.

Related Service Information Under 1 CFR Part 51

Bombardier, Inc., has issued the following service information:

Bombardier Service Bulletin 670BA-27-062, Revision C,
dated February 13, 2015. This service information describes procedures
for replacing the elevator lever assemblies and control rods.

Bombardier Service Bulletin 670BA-27-062, Revision E,
dated June 8, 2017. This service information describes procedures for
replacing the elevator lever assemblies and control rods, and a
detailed visual inspection of the key washers and self-locking nuts of
the elevator control linkages and corrective actions, which include
bending the tab of the key washers and re-torqueing the self-locking
nuts.

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 these
same type designs.

Costs of Compliance

We estimate that this proposed AD affects 549 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 removing Airworthiness Directive (AD)
2015-17-04, Amendment 39-18237 (80 FR 50556, August 20, 2015), and
adding the following new AD: