DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2016-7026; Directorate Identifier 2016-CE-016-AD;
Amendment 39-18620; AD 2016-17-07]
RIN 2120-AA64

Airworthiness Directives; PILATUS Aircraft Ltd. 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 PILATUS
Aircraft Ltd. Model PC-7 airplanes. This AD results from mandatory
continuing airworthiness information (MCAI) issued by an aviation
authority of another country to identify and correct an unsafe
condition on an aviation product. The MCAI describes the unsafe
condition as stress corrosion cracking on the main frame on frame 11
left and right fittings. We are issuing this AD to require actions to
address the unsafe condition on these products.

DATES: This AD is effective September 30, 2016.
The Director of the Federal Register approved the incorporation by
reference of a certain publication listed in the AD as of September 30,
2016.

ADDRESSES: You may examine the AD docket on the Internet at http://www.
regulations.gov by searching for and locating Docket No. FAA-2016-
7026; or in person at Document 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 service information identified in this AD, contact PILATUS
Aircraft Ltd., Customer Technical Support (MCC), P.O. Box 992, CH-6371
Stans, Switzerland; phone: +41 (0)41 619 67 74; fax: +41 (0)41 619 67
73; email: aircraft.com">techsupport@pilatus-aircraft.com; Internet: http://
www.pilatus-aircraft.com. You may view this referenced service
information at the FAA, Small Airplane Directorate, 901 Locust, Kansas
City, Missouri 64106. For information on the availability of this
material at the FAA, call (816) 329-4148. It is also available on the
Internet at http://www.regulations.gov by searching for Docket No. FAA-
2016-7026.

FOR FURTHER INFORMATION CONTACT: Doug Rudolph, Aerospace Engineer, FAA,
Small Airplane Directorate, 901 Locust, Room 301, Kansas City, Missouri
64106; telephone: (816) 329-4059; fax: (816) 329-4090; email:
doug.rudolph@faa.gov.

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 PILATUS Aircraft Ltd. Model
PC-7 airplanes. The NPRM was published in the Federal Register on June
9, 2016 (81 FR 37166). The NPRM proposed to correct an unsafe condition
for the specified products and was based on mandatory continuing
airworthiness information (MCAI) originated by an aviation authority of
another country. The MCAI states:

This Airworthiness Directive (AD) is prompted due to a report of
Stress Corrosion Cracking (SCC) on the Main Frame on Frame (FR) 11
left fitting Part Number (P/N) 112.35.07.489 and right fitting P/N
112.35.07.490.
Such a condition, if left uncorrected, could lead to potential
loss of the horizontal stabilizer.
In order to correct and control the situation, this AD requires
a one-time check to identify the material specification and inspect
the affected areas of the airframe that are made of aluminum alloy
AA2024-T351. Any structural parts of the aircraft structure found to
be cracked must be reported to Pilatus prior to further flight.

The MCAI can be found in the AD docket on the Internet at: https://www.regulations.gov/document?D=FAA-2016-7026-0002.

Comments

We gave the public the opportunity to participate in developing
this AD. We received no comments on the NPRM (81 FR 37166, June 9,
2016) 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 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 (81 FR 37166, June 9, 2016) for correcting the unsafe
condition; and
Do not add any additional burden upon the public than
was already proposed in the NPRM (81 FR 37166, June 9, 2016).

Related Service Information Under 1 CFR Part 51

We reviewed PILATUS Aircraft Ltd. PC-7 Service Bulletin No: 53-013;
and PILATUS Aircraft Ltd. PC-7 Service Bulletin No: 53-014, both dated
February 25, 2016. PILATUS Aircraft Ltd. PC-7 Service Bulletin No: 53-
013, dated February 25, 2016, describes procedures for initial and
repetitive inspection of the main frame FR11 left and right fittings
for stress corrosion cracking; and PILATUS Aircraft Ltd. PC-7 Service
Bulletin No: 53-014, dated February 25, 2016, describes procedures for
replacement of the main frame FR11 left and right fittings when
necessary. 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 the AD.

Costs of Compliance

We estimate that this AD will affect 19 products of U.S. registry.
We also estimate that it would take about 3 work-hours per product to
check the material specification of the fittings and 11 work-hours per
product to inspect the 2014-T351 fittings as required in order to
comply with the basic requirements of this AD. The average labor rate
is $85 per work-hour.
Based on these figures, we estimate the cost of this AD on U.S.
operators to be $17,765, or $935 per product.
In addition, we estimate that any necessary follow-on actions would
take about 19 work-hours and require parts costing $5,000 for a cost of
$6,615 per product. We have no way of determining the number of
products that may need these actions.
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 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
by searching for and locating Docket No. FAA-2016-
7026; 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 the NPRM, the regulatory evaluation, any comments received,
and other information. The street address for the Docket 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
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 AD: