DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2015-0929; Directorate Identifier 2014-NM-218-AD;
Amendment 39-18323; AD 2015-23-07]
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 BD-100-1A10 (Challenger 300) airplanes. This AD
was prompted by multiple reports of chafing found on an electrical
wiring harness in the aft equipment bay, caused by contact between the
wiring harness and a neighboring hydraulic line. This AD requires an
inspection, repair if necessary, and modification of the wiring harness
installation to ensure that the wiring harness routing is correct and a
minimum clearance between the wire and the hydraulic line is
maintained. We are issuing this AD to detect and correct chafing on an
electrical wiring harness, which could cause an electrical short
circuit or lead to a malfunction of the flight control system, the
engine indication system, or the hydraulic power control system; and
adversely affect the continued safe operation and landing of the
airplane.

DATES: This AD becomes effective December 22, 2015.
The Director of the Federal Register approved the incorporation by
reference of a certain publication listed in this AD as of December 22,
2015.

ADDRESSES: You may examine the AD docket on the Internet at http://www.regulations.gov/#!docketDetail;D=FAA-2015-0929 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., 400 Cote-Vertu Road West, Dorval, Quebec H4S 1Y9,
Canada; telephone: 514-855-5000; fax: 514-855-7401; email:
thd.crj@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-2015-0929.

FOR FURTHER INFORMATION CONTACT: Assata Dessaline, Aerospace Engineer,
Avionics and Service Branch, ANE-172, FAA, New York Aircraft
Certification Office, 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 BD-100-1A10 (Challenger 300) airplanes. The NPRM published in the
Federal Register on May 8, 2015 (80 FR 26490).
Transport Canada Civil Aviation (TCCA), which is the aviation
authority for Canada, has issued Canadian Airworthiness Directive CF-
2014-32, dated September 8, 2014 (referred to after this as the
Mandatory Continuing Airworthiness Information, or ``the MCAI''), to
correct an unsafe condition for certain Bombardier, Inc. Model BD-100-
1A10 (Challenger 300) airplanes. The MCAI states:

There have been multiple in-service reports of chafing found on
an electrical wiring harness in the aft equipment bay. An
investigation determined that the chafing was attributed to contact
between the wiring harness and a neighboring hydraulic line. This
chafing could cause an electrical short circuit or lead to a
malfunction of the flight control system, the engine indication
system, or the hydraulic power control system; which could adversely
affect the continued safe operation and landing of the aeroplane.
This [Canadian] AD mandates the inspection [general visual
inspection], rectification as required [repair of damage (including
wear and chafing)], and modification of the wiring harness
installation to ensure the correct wiring routing and a minimum
clearance between the wire and the hydraulic line is maintained.

You may examine the MCAI in the AD docket on the Internet at http://www.regulations.gov/#!documentDetail;D=FAA-2015-0929-0002.

Comments

We gave the public the opportunity to participate in developing
this AD. We received no comments on the NPRM (80 FR 26490, May 8, 2015)
or on the determination of the cost to the public.

Conclusion

We reviewed the relevant data and determined that air safety and
the public interest require adopting this AD as proposed except for
minor editorial changes. We have determined that these minor changes:
Are consistent with the intent that was proposed in the
NPRM (80 FR 26490, May 8, 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 26490, May 8, 2015).

Related Service Information Under 1 CFR Part 51

Bombardier, Inc. has issued Service Bulletin 100-24-24, dated June
6, 2014. The service information describes procedures for an
inspection, repair if necessary, and modification of the wiring harness
installation to prevent contact with the hydraulic line. 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 107 airplanes of U.S. registry.
We also estimate that it will take about 4 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 $64 per
product. Based on these figures, we estimate the cost of this AD on
U.S. operators to be $43,228, or $404 per product.
We have received no definitive data that would enable us to provide
cost estimates for the on-condition actions specified in this AD. We
have no way of determining the number of aircraft that might need these
actions.
According to the manufacturer, all 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.

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/#!docketDetail;D=FAA-2015-0929; 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):