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

ACTION: Final rule.

SUMMARY: We are adopting a new airworthiness directive (AD) for certain
Bombardier, Inc. Model DHC-8-400 series airplanes. This AD was prompted
by reports of failure of the high pressure shutoff valves (HPSOVs)
causing the timer and monitor unit (TMU) to become inoperative since
the HPSOV and the TMU are on the same circuit breaker. This AD requires
a wiring modification to segregate the HPSOV power supply from the TMU.
We are issuing this AD to prevent an inoperative TMU, which could
result in the loss of the automatic de-icing mode, and lead to an
increased workload for the flight crew and loss of control of the
airplane.

DATES: This AD becomes effective September 19, 2014.
The Director of the Federal Register approved the incorporation by
reference of a certain publication listed in this AD as of September
19, 2014.

ADDRESSES: You may examine the AD docket on the Internet at http://www.regulations.gov/#!docketDetail;D=FAA-2013-1068; 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 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 2, 2014 (79 FR 76). Transport Canada Civil Aviation
(TCCA), which is the aviation authority for Canada, has issued Canadian
Airworthiness Directive CF-2013-27, dated September 25, 2013 (referred
to after this as the Mandatory Continuing Airworthiness Information, or
``the MCAI''), to correct an unsafe condition for the specified
products. The MCAI states:

There have been several in-service reports of the failure of
high pressure shutoff valves (HPSOV) causing the Timer and Monitor
Unit (TMU) to become inoperative since the HPSOV and TMU are on the
same circuit breaker.
An inoperative TMU would result in the loss of the automatic de-
icing mode and would lead to an increased workload for the
flightcrew. In the case where additional failures occur during a
critical flight phase, the significantly increased workload could
lead to loss of control of the aeroplane.
This [Canadian] AD mandates a wiring modification to segregate
the HPSOV power supply from the TMU.

You may examine the MCAI in the AD docket on the Internet at http://www.regulations.gov/#!documentDetail;D=FAA-2013-1068-0002.

Comments

We gave the public the opportunity to participate in developing
this AD. The following presents the comment received on the NPRM (79 FR
76, January 2, 2014) and the FAA's response to the comment.

Request To Use the Latest Service Information

Horizon Air requested that we revise the proposed AD (79 FR 76,
January 2, 2014) to allow compliance for Bombardier Service Bulletin
84-36-04, Revision B, dated January 2, 2014, or Bombardier Service
Bulletin 84-36-04, Revision A, dated April 17, 2013.
We agree with the commenter's request to reference the latest
service information. We have revised this AD by referencing Bombardier
Service Bulletin 84-36-04, Revision B, dated January 2, 2014,
throughout this AD. We have also revised paragraph (h) of this AD to
give credit for actions done before the effective date of this AD in
accordance with Bombardier Service Bulletin 84-36-04, Revision A, dated
April 17, 2013, as well as Bombardier Service Bulletin 84-36-04, dated
March 13, 2013.

``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 76, January 2, 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 76, January 2, 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.

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 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 76, January 2, 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 76, January 2, 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 78 airplanes of U.S. registry.
We also estimate that it will take about 7 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 $0 per
product. Based on these figures, we estimate the cost of this AD on
U.S. operators to be $46,410, or $595 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#!docketDetail;D=FAA-2013-1068; 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):