AGENCY: Federal Aviation Administration
(FAA), Department of
ACTION: Final rule.
SUMMARY: We are adopting a new airworthiness directive (AD) for
Bombardier, Inc. Model DHC-8-400 series airplanes. This AD was prompted
by reports of difficulties in opening the airstair door. This AD
requires inspecting the structure and gearbox drain paths for blockages
by sealant, and removing any blockages. We are issuing this AD to
detect and correct drain paths blocked by sealant, resulting in an
airstair door that is unable to be opened, which could hinder
evacuation in the event of an emergency.
DATES: This AD becomes effective April 25, 2012.
The Director of the Federal Register approved the incorporation by
reference of a certain publication listed in this AD as of April 25,
ADDRESSES: You may examine the AD docket on the Internet at http://www.
regulations.gov or in person at the U.S. Department of
Transportation, Docket Operations, M-30, West Building Ground Floor,
Room W12-140, 1200 New Jersey Avenue SE., Washington, DC.
FOR FURTHER INFORMATION CONTACT: Cesar Gomez, Aerospace Engineer,
Airframe and Mechanical Systems Branch, ANE-171, FAA, New York Aircraft
Certification Office, 1600 Stewart Avenue, Suite 410, Westbury, New
York 11590; telephone (516) 228-7318; fax (516) 794-5531.
We issued a notice of proposed rulemaking (NPRM) to amend 14 CFR
part 39 to include an AD that would apply to the specified products.
That NPRM was published in the Federal Register on October 19, 2011 (76
FR 64849), and proposed to correct an unsafe condition for the
specified products. The MCAI states:
Several operators have reported difficulties in opening the
airstair door. Investigation revealed that the airstair door gearbox
drain paths were blocked by sealant, causing water to accumulate and
freeze in the gearbox assembly. An airstair door that is unable to
be opened could hinder evacuation in the event of an emergency.
This [Canadian] directive mandates a one-time [general visual]
inspection [for sealant blockages] and [removal of any] sealant
interfering with the airstair gearbox drain paths.
You may obtain further information by examining the MCAI in the AD
We gave the public the opportunity to participate in developing
this AD. We considered the comment received. The commenter, Air Line
Pilots Association, International, supports the NPRM (76 FR 64849,
October 19, 2011).
We reviewed the available data, including the comment received, and
determined that air safety and the public interest require adopting the
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 (76 FR 64849, October 19, 2011) for correcting the unsafe
Do not add any additional burden upon the public than was
already proposed in the NPRM (76 FR 64849, October 19, 2011).
Costs of Compliance
We estimate that this AD will affect about 83 products of U.S.
registry. We also estimate that it will take about 2 work-hours per
product to comply with the basic requirements of this AD. The average
labor rate is $85 per work-hour. Where the service information lists
required parts costs that are covered under warranty, we have assumed
that there will be no charge for these parts. As we do not control
warranty coverage for affected parties, some parties may incur costs
higher than estimated here. Based on these figures, we estimate the
cost of this AD to the U.S. operators to be $14,110, or $170 per
In addition, we estimate that any necessary follow-on actions would
take about 3 work-hours and require parts costing $0, for a cost of
$255. We have no way of determining the number of products that may
need these actions.
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
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
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 this proposed
1. Is not a ``significant regulatory action'' under Executive Order
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.
We prepared a regulatory evaluation of the estimated costs to
comply with this AD and placed it in the AD docket.
Examining the AD Docket
You may examine the AD docket on the Internet at http://www.regulations.gov;
or in person at the Docket Operations office
between 9 a.m. and 5 p.m., Monday through Friday, except Federal
holidays. The AD docket contains the NPRM (76 FR 64849, October 19,
2011), 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. Comments will
be available in the AD docket shortly after receipt.
List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, Incorporation by
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 AD: