DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2016-9387; Directorate Identifier 2016-NM-182-AD;
Amendment 39-18926; AD 2017-12-11]
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 airplanes. This AD was prompted by
a report that the equipment racks were not designed to support the
actual weight of all the equipment and the secondary direct current
power centers under all loading conditions. This AD requires modifying
the equipment racks. We are issuing this AD to address the unsafe
condition on these products.

DATES: This AD is effective July 20, 2017.

The Director of the Federal Register approved the incorporation by
reference of certain publications listed in this AD as of July 20, 2017.

ADDRESSES: For service information identified in this final rule,
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-2016-
9387.

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-2016-
9387; 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: Aziz Ahmed, Aerospace Engineer,
Airframe and Mechanical Systems Branch, ANE-171, FAA, New York Aircraft
Certification Office (ACO), 1600 Stewart Avenue, Suite 410, Westbury,
NY 11590; telephone 516-228-7329; 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 airplanes. The NPRM published in the Federal Register
on March 23, 2017 (82 FR 14837). The NPRM was prompted by a recent
design review of the equipment racks which revealed that the left-hand
side (LHS) and right-hand side (RHS) equipment racks were not designed
to support the actual weight of all the equipment and the secondary
direct current power centers under all loading conditions. The NPRM
proposed to require modifying the equipment racks. We are
issuing this AD to prevent structural failure of the LHS or RHS
equipment racks in the event of a high energy emergency landing or
runway excursion, which could result in blockage of the emergency exit
for the flightcrew.

Transport Canada Civil Aviation (TCCA), which is the aviation
authority for Canada, has issued Canadian Airworthiness Directive CF-
2016-26, dated September 14, 2016 (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 airplanes. The MCAI states:

During a recent design review, a Bombardier equipment supplier
discovered that the weight of the Secondary Direct Current (DC)
Power Center was incorrectly reported to the structural partner(s)
via their equipment interface drawing. Consequently, the left-hand
side (LHS) and right-hand side (RHS) equipment racks were not
designed to support the actual weight of all the equipment and the
Secondary DC Power Centers under all loading conditions. In the
event of a high energy emergency landing or runway excursion, the
structural failure of the LHS or RHS equipment racks may result in
the blockage of the emergency escape route for the pilot(s) and crew
if this condition is not corrected.

Required actions include modifying the equipment racks. 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-2016-9387.

Comments

We gave the public the opportunity to participate in developing
this AD. We received no comments on the NPRM 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 for correcting the unsafe condition; and

Do not add any additional burden upon the public than was
already proposed in the NPRM.

Related Service Information Under 1 CFR Part 51

We reviewed Bombardier Service Bulletin 100-25-39, dated October
26, 2015; and Bombardier Service Bulletin 350-25-002, dated October 26,
2015. This service information describes procedures for modifying the
equipment racks. These documents are distinct since they apply to
airplanes having different serial numbers. 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 161 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.

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):