DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2014-1050; Directorate Identifier 2014-NM-123-AD;
Amendment 39-18241; AD 2015-17-08]
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 DHC-8-400 series airplanes. This AD was prompted
by an in-service report of an uncommanded and unannunciated nose wheel
steering during airplane pushback from the gate. This AD requires
installing new cable assemblies with a pull-down resistor. We are
issuing this AD to prevent an uncommanded nose wheel steering during
takeoff or landing in the event of an open circuit in the steering
system, and possible consequent runway excursion.
DATES: This AD becomes effective September 29, 2015.
The Director of the Federal Register approved the incorporation by
reference of a certain publication listed in this AD as of September
29, 2015.
ADDRESSES: You may examine the AD docket on the Internet at http://www.regulations.gov/#!docketDetail;D=FAA-2014-1050
or in person at the
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.
For service information identified in this AD, contact Bombardier,
Inc., Q-Series Technical Help Desk, 123 Garratt Boulevard, Toronto,
Ontario M3K 1Y5, Canada; telephone 416-375-4000; fax 416-375-4539;
email thd.qseries@aero.bombardier.com; Internet http://www.bombardier.com.
You may view this referenced service information at
the FAA, Transport Airplane Directorate, 1601 Lind Avenue SW., Renton,
WA. For information on the availability of this material at the FAA,
call 425-227-1221. It is also available on the Internet at http://www.
regulations.gov by searching for and locating Docket No. FAA-2014-
1050.
FOR FURTHER INFORMATION CONTACT: Assata Dessaline, Aerospace Engineer,
Avionics and Services Branch, ANE-172, FAA, New York Aircraft
Certification Office (ACO), 1600 Stewart Avenue, Suite 410, Westbury,
NY 11590; telephone (516) 228-7301; 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 DHC-8-400 series airplanes. The NPRM published in the Federal
Register on January 23, 2015 (80 FR 3504).
The Transport Canada Civil Aviation (TCCA), which is the aviation
authority for Canada, has issued Canadian Airworthiness Directive CF-
2013-38, dated November 28, 2013 (referred to after this as the
Mandatory Continuing Airworthiness Information, or ``the MCAI''), to
correct an unsafe condition for certain Bombardier, Inc. Model DHC-8-
400, -401, and -402 series airplanes. The MCAI states:
There has been one in-service report of an un-commanded and un-
annunciated nose wheel steering during aeroplane push-back from the
gate. The investigation revealed that a design deficiency exists
within the steering control unit (SCU) where an open circuit may not
be adequately detected and annunciated to the flight crew. A
sustained open circuit could result in an un-commanded and un-
annunciated nose wheel steering input.
Un-commanded nose wheel steering during takeoff or landing may
lead to a runway excursion.
This [Canadian] AD mandates the installation of new cable
assemblies, with a pull-down resistor, to ensure that the nose wheel
steering system reverts to fail-safe free castor mode in the event
of an open circuit in the steering system.
You may examine the MCAI in the AD docket on the Internet at http://www.regulations.gov/#!documentDetail;D=FAA-2014-1050-0002.
Comments
We gave the public the opportunity to participate in developing
this AD. The following presents the comment received on the NPRM (80 FR
3504, January 23, 2015) and the FAA's response to each comment.
Request To Remove Certain Service Information Procedures
Horizon Air requested that we amend paragraph (g) of the proposed
AD (80 FR 3504, January 23, 2015) to exclude Part A, ``Job Set-up,''
and Part C ``Close Out,'' sections of the Accomplishment Instructions
in Bombardier Service Bulletin 84-32-122, Revision A, dated August 28,
2013
Horizon Air stated that Part A, ``Job Set-up,'' and Part C, ``Close Out,''
do not
directly correct the unsafe condition. Horizon Air explained that
requiring operators to perform the actions in these sections in a
specific manner restricts the operator's ability to perform other
maintenance in conjunction with performing the corrective action.
We agree with the commenter's request to exclude the ``Job Set-up''
and ``Close Out'' sections of the Accomplishment Instructions of
Bombardier Service Bulletin 84-32-122, Revision A, dated August 28,
2013. We have revised paragraph (g) of this AD to require
accomplishment of only paragraph B., ``Procedure,'' of the
Accomplishment Instructions of Bombardier Service Bulletin 84-32-122,
Revision A, dated October 4, 2013.
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 change described previously and minor editorial
changes. We have determined that these minor changes:
Are consistent with the intent that was proposed in the
NPRM (80 FR 3504, January 23, 2015) for correcting the unsafe
condition; and
Do not add any additional burden upon the public than was
already proposed in the NPRM (80 FR 3504, January 23, 2015).
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. has issued Service Bulletin 84-32-122, Revision A,
dated October 4, 2013. This service information describes procedures
for incorporating Bombardier Modification Summary (Modsum) 4-126585 to
install new cable assemblies with a pull-down resistor to the pilot
hand control and rudder pedal potentiometer of the nose wheel steering
control unit. 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 of this
AD.
Costs of Compliance
We estimate that this AD affects 81 airplanes of U.S. registry.
We also estimate that it will take about 6 work-hours per product
to comply with the basic requirements of this AD. The average labor
rate is $85 per work-hour. Required parts will cost about $2,541 per
product. Based on these figures, we estimate the cost of this AD on
U.S. operators to be $247,131, or $3,051 per product.
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.
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.
Examining the AD Docket
You may examine the AD docket on the Internet at http://www.regulations.gov/#!documentDetail;D=FAA-2014-1050;
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 Operations office
(telephone 800-647-5527) is in the ADDRESSES section.
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):
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