AGENCY: Federal Aviation Administration (FAA), Department of
Transportation (DOT).

ACTION: Final rule.

SUMMARY: We are superseding Airworthiness Directive (AD) 2011-15-09 for
certain Bombardier, Inc. Model DHC-8-400, -401, and -402 airplanes. AD
2011-15-09 required repetitive inspections for proper operation of the
main landing gear (MLG) alternate extension system (AES), and
corrective actions if necessary. This new AD requires, for certain
airplanes, new repetitive inspections for proper operation of the MLG
AES, and corrective actions if necessary. This new AD also requires
eventually replacing the MLG AES cam mechanism assembly with a new
assembly, which terminates the repetitive inspections for those
airplanes. This AD was prompted by a determination that, for certain
airplanes not affected by AD 2011-15-09, a different MLG AES cam
mechanism assembly was installed, resulting in input lever fractures
and inability to open the MLG door; those assemblies could be subject
to the same unsafe condition in AD 2011-15-09. We are issuing this AD
to prevent improper operation of the cam mechanism or rupture of the
door release cable, which could result in loss of control of the airplane during
landing.

DATES: This AD becomes effective September 23, 2014.
The Director of the Federal Register approved the incorporation by
reference of certain publications listed in this AD as of September 23,
2014.
The Director of the Federal Register approved the incorporation by
reference of a certain other publication listed in this AD as of August
2, 2011 (76 FR 42033, July 18, 2011).

ADDRESSES: You may examine the AD docket on the Internet at http://www.regulations.gov/#!docketDetail;D=FAA-2014-0129; 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.

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, 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 to supersede AD 2011-15-09, Amendment 39-16756 (76 FR 42033,
July 18, 2011). AD 2011-15-09 applied to certain Bombardier, Inc. Model
DHC-8-400, -401, and -402 airplanes. The NPRM published in the Federal
Register on March 5, 2014 (79 FR 12428).
Transport Canada Civil Aviation (TCCA), which is the aviation
authority for Canada, has issued Canadian Airworthiness Directive CF-
2011-01R2, dated May 21, 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 airplanes. The MCAI states:

Two cases of the main landing gear (MLG) alternate extension
system (AES) cam mechanism failure were found during line checks.
The cam mechanism operates the cable to open the MLG door and
releases the MLG uplock in sequence. In the case where it is
necessary to deploy the MLG using the AES, the failure of the MLG
AES cam mechanism on one side will lead to an unsafe asymmetrical
landing configuration.
Preliminary investigation indicates that the cam mechanism
failure may have occurred and remained dormant after a previous AES
operation. The cam mechanism may not have fully returned to the
normal rested position. With the cam mechanism out of normal rested
position, normal powered landing gear door operation could introduce
sufficient loads to fracture the cam mechanism or rupture the door
release cable.
This [Canadian] AD mandates the initial and subsequent
[detailed] inspections for proper operation of the MLG AES cam
mechanism, and rectify [repair or replace cam assembly with new or
serviceable cam assembly] as necessary.
Since the original issue of this [Canadian] AD, Bombardier Inc.
has determined that the existing inspection procedure is
insufficient for verification of proper MLG AES cam mechanism
operation, and has superseded this inspection procedure. Revision 1
of this [Canadian] AD mandates the use of the revised inspection
[and rectification] procedure.
Prior to the introduction of MLG AES cam mechanism assembly part
number (P/N) 48510-5 as terminating action, an interim MLG AES cam
mechanism assembly P/N 48510-3 was introduced.
Revision 2 of this [Canadian] AD updates the applicability
paragraph, updates the MLG AES cam mechanism inspection criteria and
mandates the terminating action.

You may examine the MCAI in the AD docket on the Internet at http://www.regulations.gov/#!docketDetail;D=FAA-2014-0129.

Comments

We gave the public the opportunity to participate in developing
this AD. We considered the comment received. The commenter supported
the NPRM (79 FR 12428, March 5, 2014).

"Contacting the Manufacturer" Paragraph in This AD

Since late 2006, we have included a standard paragraph titled
``Airworthy Product'' in all MCAI ADs in which the FAA develops an AD
based on a foreign authority's AD.
The MCAI or referenced service information in an FAA AD often
directs the owner/operator to contact the manufacturer for corrective
actions, such as a repair. Briefly, the Airworthy Product paragraph
allowed owners/operators to use corrective actions provided by the
manufacturer if those actions were FAA-approved. In addition, the
paragraph stated that any actions approved by the State of Design
Authority (or its delegated agent) are considered to be FAA-approved.
In the NPRM (79 FR 12428, March 5, 2014), we proposed to prevent
the use of repairs that were not specifically developed to correct the
unsafe condition, by requiring that the repair approval provided by the
State of Design Authority or its delegated agent specifically refer to
this FAA AD. This change was intended to clarify the method of
compliance and to provide operators with better visibility of repairs
that are specifically developed and approved to correct the unsafe
condition. In addition, we proposed to change the phrase ``its
delegated agent'' to include a design approval holder (DAH) with State
of Design Authority design organization approval (DOA), as applicable,
to refer to a DAH authorized to approve required repairs for the
proposed AD.
No comments were provided to the NPRM (79 FR 12428, March 5, 2014)
about these proposed changes. However, a comment was provided for an
NPRM having Directorate Identifier 2012-NM-101-AD (78 FR 78285,
December 26, 2013). The commenter stated the following: ``The proposed
wording, being specific to repairs, eliminates the interpretation that
Airbus messages are acceptable for approving minor deviations
(corrective actions) needed during accomplishment of an AD mandated
Airbus service bulletin.''
This comment has made the FAA aware that some operators have
misunderstood or misinterpreted the Airworthy Product paragraph to
allow the owner/operator to use messages provided by the manufacturer
as approval of deviations during the accomplishment of an AD-mandated
action. The Airworthy Product paragraph does not approve messages or
other information provided by the manufacturer for deviations to the
requirements of the AD-mandated actions. The Airworthy Product
paragraph only addresses the requirement to contact the manufacturer
for corrective actions for the identified unsafe condition and does not
cover deviations from other AD requirements. However, deviations to AD-
required actions are addressed in 14 CFR 39.17, and anyone may request
the approval for an alternative method of compliance to the AD-required
actions using the procedures found in 14 CFR 39.19.
To address this misunderstanding and misinterpretation of the
Airworthy Product paragraph, we have changed the
paragraph and retitled it ``Contacting the Manufacturer.'' This
paragraph now clarifies that for any requirement in this AD to obtain
corrective actions from a manufacturer, the actions must be
accomplished using a method approved by the FAA, TCCA, or Bombardier,
Inc.'s TCCA Design Approval Organization (DAO).
The Contacting the Manufacturer paragraph also clarifies that, if
approved by the DAO, the approval must include the DAO-authorized
signature. The DAO signature indicates that the data and information
contained in the document are TCCA-approved, which is also FAA-
approved. Messages and other information provided by the manufacturer
that do not contain the DAO-authorized signature approval are not TCCA-
approved, unless TCCA directly approves the manufacturer's message or
other information.
This clarification does not remove flexibility previously afforded
by the Airworthy Product paragraph. Consistent with long-standing FAA
policy, such flexibility was never intended for required actions. This
is also consistent with the recommendation of the Airworthiness
Directive Implementation Aviation Rulemaking Committee to increase
flexibility in complying with ADs by identifying those actions in
manufacturers' service instructions that are ``Required for
Compliance'' with ADs. We continue to work with manufacturers to
implement this recommendation. But once we determine that an action is
required, any deviation from the requirement must be approved as an
alternative method of compliance.
Other commenters to the NPRM having Directorate Identifier 2012-NM-
101-AD (78 FR 78285, December 26, 2013) pointed out that in many cases
the foreign manufacturer's service bulletin and the foreign authority's
MCAI might have been issued some time before the FAA AD. Therefore, the
DOA might have provided U.S. operators with an approved repair,
developed with full awareness of the unsafe condition, before the FAA
AD is issued. Under these circumstances, to comply with the FAA AD, the
operator would be required to go back to the manufacturer's DOA and
obtain a new approval document, adding time and expense to the
compliance process with no safety benefit.
Based on these comments, we removed the requirement that the DAH-
provided repair specifically refer to this AD. Before adopting such a
requirement, the FAA will coordinate with affected DAHs and verify they
are prepared to implement means to ensure that their repair approvals
consider the unsafe condition addressed in this AD. Any such
requirements will be adopted through the normal AD rulemaking process,
including notice-and-comment procedures, when appropriate.
We also have decided not to include a generic reference to either
the ``delegated agent'' or ``DAH with State of Design Authority design
organization approval,'' but instead we have provided the specific
delegation approval granted by the State of Design Authority for the
DAH throughout this AD.

Change to Paragraph (g)(3) of This AD

For clarity purposes, we have revised paragraph (g)(3) of this AD
by adding new paragraphs (g)(3)(i) and (g)(3)(ii) to this AD.

Conclusion

We reviewed the available data, including 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 (79 FR 12428, March 5, 2014) for correcting the unsafe condition;
and
Do not add any additional burden upon the public than was
already proposed in the NPRM (79 FR 12428, March 5, 2014).
We also determined that these changes will not increase the
economic burden on any operator or increase the scope of this AD.

Costs of Compliance

We estimate that this AD affects 75 airplanes of U.S. registry.

Estimated Costs

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-2014-0129; 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 removing Airworthiness Directive (AD)
2011-15-09, Amendment 39-16756 (76 FR 42033, July 18, 2011), and adding
the following new AD: