DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2017-0495; Product Identifier 2017-NM-017-AD; Amendment
39-19222; AD 2018-06-02]
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 all
Bombardier, Inc., Model CL-600-2B19 (Regional Jet Series 100 & 440),
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. This AD was prompted by development of a
modification to prevent uncommanded rudder movement during flight. This
AD requires modifying the wiring harness of the yaw damper control
system. We are issuing this AD to address the unsafe condition on these
products.

DATES: This AD is effective April 27, 2018.
The Director of the Federal Register approved the incorporation by
reference of certain publications listed in this AD as of April 27,
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 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. It
is also available on the internet at http://www.regulations.gov by
searching for and locating Docket No. FAA-2017-0495.

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-
0495; 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 AD, the regulatory evaluation, any comments received, and
other information. The street address for the Docket Office (telephone
800-647-5527) is Docket Management Facility, U.S. Department of
Transportation, Docket Operations, M-30, West Building Ground Floor,
Room W12-140, 1200 New Jersey Avenue SE, Washington, DC 20590.

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

SUPPLEMENTARY INFORMATION:

Discussion

We issued a notice of proposed rulemaking (NPRM) to amend 14 CFR
part 39 by adding an AD that would apply to all Bombardier, Inc., Model
CL-600-2B19 (Regional Jet Series 100 & 440), 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 NPRM published in the Federal Register on May 31, 2017 (82 FR
24897) (``the NPRM''). The NPRM was prompted by development of a
modification to prevent uncommanded rudder movement during flight. The
NPRM proposed to require modifying the wiring harness of the yaw damper
control system. We are issuing this AD to prevent uncommanded rudder
movement and consequent loss of the ability to control the airplane.
Transport Canada Civil Aviation (TCCA), which is the aviation
authority for Canada, has issued Canadian Airworthiness Directive CF-
2017-06, effective February 14, 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-600-2B19
(Regional Jet Series 100 & 440), 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:

[Canadian] AD CF-2013-13 was issued on 28 May 2013 [related to
FAA AD 2013-14-11, Amendment 39-17516 (78 FR 44871, July 25, 2013)
(``AD 2013-14-11'')] to mandate the introduction of an emergency
procedure to the Aeroplane Flight Manual to address the uncommanded
rudder movement.
Since the original issue of [Canadian] AD CF-2013-13, Bombardier
Aerospace has developed a wiring modification for the yaw damper
control system to prevent uncommanded movement of the rudder [and
consequent loss of the ability to control the airplane].
This [Canadian] AD mandates the wiring modification for the yaw
damper control system * * *.

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-2017-0495.

Comments

We gave the public the opportunity to participate in developing
this AD. The following presents the comments received on the NPRM and
the FAA's response to each comment.

Support for the NPRM

The Air Line Pilots Association, International (ALPA), agreed with
the intent of the NPRM.

Request To Clarify Credit for Certain Service Information

SkyWest Airlines and Ahmad Lababidi asked that we revise paragraph
(h) of the proposed AD to clarify the credit language for accomplishing
the engineering orders in conjunction with the referenced service
information. Ahmad Lababidi stated that Service Non-Incorporated
Engineering Order (SNIEO) K601R50211 S02, dated October 31, 2014, was
issued for certain airplane configurations where the wire connector was
changed from pin type to socket type. The commenters added that SNIEOs
K601R50211 S03, dated April 21, 2015, and S04, dated April 24, 2015,
were issued to clarify certain splicing, capping, and stowing
locations, and to reduce the work hours for accomplishing the actions
specified in the service bulletin. The commenters added that it is not
necessary to do the engineering orders in conjunction with the
referenced service information. SkyWest reported accomplishing the
modification on some airplanes using only the applicable service
bulletin without any reference to the SNIEOs specified in paragraph (h)
of the proposed AD.
We agree with the commenters' requests for the reasons provided. We
have revised paragraphs (h)(1)(i) and (h)(1)(ii) of this AD to remove
reference to the SNIEOs, which are not required to be used in
conjunction with the referenced service information.

Request To Revise Parts Installation Limitations Paragraph

Air Wisconsin asked that we revise paragraph (i) of the proposed AD
(Parts Installation Limitations) to exclude parts on which the actions
in the referenced service information have been done.
We acknowledge the commenter's request. However, paragraph (i) of
this AD already prohibits installation of a yaw damper actuator . . .
``unless it has been modified in accordance with the applicable service
information specified in table 1 to paragraph (g) of this AD.'' Since
existing language meets the intent of the commenter's request, we have
not changed this AD in this regard.

Conclusion

We reviewed the relevant data, considered the comments received,
and determined that air safety and the public interest require adopting
this AD with the changes described previously, and minor editorial
changes. We have determined that these minor changes:
Are consistent with the intent that was proposed in the
NPRM for correcting the unsafe condition; and
Do not add any additional burden upon the public than was
already proposed in the NPRM.
We also determined that these changes will not increase the
economic burden on any operator or increase the scope of this AD.

Related Service Information Under 1 CFR Part 51

Bombardier has issued Service Bulletin 601R-22-017, Revision C,
dated May 11, 2016; and Service Bulletin 670BA-22-007, Revision A,
dated February 16, 2016. This service information describes procedures
for modifying the wiring harness of the yaw damper control system.
These documents are distinct since they apply to different airplane
models. 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 1,006 airplanes of U.S. registry.
We estimate the following costs to comply with this AD:

Estimated Costs

According to the manufacturer, some of the costs of this AD may be
covered under warranty, thereby reducing the cost impact on affected
individuals. We do not control warranty coverage for affected
individuals. As a result, we have included all costs in our cost
estimate.

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 to
the Director of the System Oversight Division.

Regulatory Findings

We determined that 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):