DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2017-0626; Product Identifier 2016-NM-210-AD; Amendment
39-19226; AD 2018-06-06]
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 certain
Bombardier, Inc., Model CL-600-2B16 (CL-604 Variant) airplanes. This AD
was prompted by reports of in-flight uncommanded rudder movements on
airplanes with an installation similar to the installation on certain
Model CL-600-2B16 (CL-604 Variant) airplanes. This AD requires
modification of the wiring harness for the yaw damper control system.
We are issuing this AD to address the unsafe condition on these
products.

DATES: This AD is effective April 19, 2018.
The Director of the Federal Register approved the incorporation by
reference of certain publications listed in this AD as of April 19,
2018.

ADDRESSES: For service information identified in this final rule,
contact Bombardier, Inc., 400 C[ocirc]te-Vertu Road West, Dorval,
Qu[eacute]bec 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-2017-0626.

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-
0626; 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, FAA, New York ACO Branch, 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 certain Bombardier, Inc.,
Model CL-600-2B16 (CL-604 Variant) airplanes. The NPRM published in the
Federal Register on June 27, 2017 (82 FR 29014) (``the NPRM''). The
NPRM was prompted by reports of in-flight uncommanded rudder movements
on airplanes with an installation similar to the installation on
certain Model CL-600-2B16 (CL-604 Variant) airplanes. The NPRM proposed
to require modification of the wiring for the yaw damper control
system. We are issuing this AD to prevent in-flight uncommanded rudder
movements, which could lead to structural failure and subsequent loss
of the airplane.
Transport Canada Civil Aviation (TCCA), which is the aviation
authority for Canada, has issued Canadian Airworthiness Directive CF-
2016-38, effective December 12, 2016 (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-
2B16 (CL-604 Variant) airplanes. The MCAI states:

The [Canadian] AD CF-2013-22 [which corresponds to FAA AD 2014-
16-06, Amendment 39-17930 (79 FR 48972, August 19, 2014)] was issued
on 12 August 2013 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-2013-22, Bombardier
Aerospace has developed a wiring modification for the yaw damper
control system to prevent uncommanded movement of the rudder.
This [Canadian] AD mandates the incorporation of Service
Bulletins (SB) 604-22-007 and 605-22-002 * * * *.

This AD requires modification of the wiring 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-2017-0626.

Comments

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

Request To Clarify Airplane Model That Experienced In-Flight
Uncommanded Rudder Movement

Bombardier, Inc., requested that the Reason section (paragraph (e)
of the proposed AD) be revised to clarify that the in-flight
uncommanded rudder movements occurred on airplanes with an installation
similar to the installation on certain Model CL-600-2B16 airplanes and
did not occur on Model CL-600-2B16 airplanes. Bombardier, Inc., stated
that it is not aware of any in-flight uncommanded rudder movements that
were experienced by operators of Model CL-600-2B16 airplanes, but as
written, the Reason section of the NPRM implied that these events
occurred on Model CL-600-2B16 airplanes.
For the reason provided by the commenter, we agree to revise the
SUMMARY and Discussion sections of this final rule and paragraph (e) of
this AD to clarify that the in-flight uncommanded rudder movements
occurred on airplanes with an installation similar to the installation
on certain Model CL-600-2B16 airplanes. We have issued AD 2013-14-11,
Amendment 39-17516 (78 FR 44871, July 25, 2013) to address the same
unsafe condition for Model CL-600-2B19 (Regional Jet Series 100 & 440)
airplanes, Model CL-600-2C10 (Regional Jet Series 700, 701, & 702)
airplanes, Model CL-600-2D15 (Regional Jet Series 705) airplanes, and
Model CL-600-2D24 (Regional Jet Series 900) airplanes.

Conclusion

We reviewed the relevant data, considered the comment 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, Inc., issued Service Bulletin 604-22-007, Revision 01,
dated July 25, 2016; and Service Bulletin 605-22-002, Revision 01,
dated July 25, 2016. This service information describes procedures for
modifying the wiring harness for the yaw damper control system. These
documents are distinct since they apply to different airplane
configurations. 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 120 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):