DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2018-1058; Product Identifier 2018-CE-051-AD]
Airworthiness Directives; Pilatus Aircraft Ltd. Airplanes
AGENCY: Federal Aviation Administration (FAA), Department of
ACTION: Notice of proposed rulemaking (NPRM).
SUMMARY: We propose to adopt a new airworthiness directive (AD)
Pilatus Aircraft Ltd. Model PC-6, PC-6/350, PC-6/350-H1, PC-6/350-H2,
PC-6/A, PC-6/A-H1, PC-6/A-H2, PC-6/B-H2, PC-6/B1-H2, PC-6/B2-H2, PC-6/
B2-H4, PC-6/C-H2, PC-6/C1-H2, PC-6-H1, and PC-6-H2 airplanes. This
proposed AD results from mandatory continuing airworthiness information
(MCAI) originated 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 sheared or missing rivets on the
horizontal stabilizer hinge bracket assemblies. We are issuing this
proposed AD to require actions to address the unsafe condition on these
DATES: We must receive comments on this proposed AD by February
ADDRESSES: You may send comments by any of the following methods:
Federal eRulemaking Portal: Go to http://www.regulations.gov. Follow the
instructions for submitting comments.
Fax: (202) 493-2251.
Mail: U.S. Department of Transportation, Docket
Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New
Jersey Avenue SE, Washington, DC 20590.
Hand Delivery: U.S. Department of Transportation, Docket
Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New
Jersey Avenue SE, Washington, DC 20590, between 9 a.m. and 5 p.m.,
Monday through Friday, except Federal holidays.
For service information identified in this proposed 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: firstname.lastname@example.org; internet: http://
www.pilatus-aircraft.com. You may review this referenced service
information at the FAA, Policy and Innovation Division, 901 Locust,
Kansas City, Missouri 64106. For information on the availability of
this material at the FAA, call (816) 329-4148.
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-2018-
1058; or in person at Docket Operations between 9 a.m. and 5 p.m.,
Monday through Friday, except Federal holidays. The AD docket contains
this proposed AD, the regulatory evaluation, any comments received, and
other information. The street address for Docket Operations (telephone
(800) 647-5527) is in the ADDRESSES section. Comments will be available
in the AD docket shortly after receipt.
FOR FURTHER INFORMATION CONTACT: Doug Rudolph, Aerospace Engineer,
Small Airplane Standards Branch, 901 Locust, Room 301, Kansas City,
Missouri 64106; telephone: (816) 329-4059; fax: (816) 329-4090; email:
We invite you to send any written relevant data, views, or
arguments about this proposed AD. Send your comments to an address
listed under the ADDRESSES section. Include "Docket No. FAA-2018-1058;
Product Identifier 2018-CE-051-AD" at the beginning of your comments.
We specifically invite comments on the overall regulatory, economic,
environmental, and energy aspects of this proposed AD. We will consider
all comments received by the closing date and may amend this proposed
AD because of those comments.
We will post all comments we receive, without change, to http://
regulations.gov, including any personal information you provide. We
will also post a report summarizing each substantive verbal contact we
receive about this proposed AD.
The European Aviation Safety Agency (EASA), which is the Technical
Agent for the Member States of the European Community, has issued AD
No. 2018-0217, dated October 10, 2018 (referred to after this as "the
MCAI"), to correct an unsafe condition for the specified products. The
During a routine inspection, the rivets of the hinge bracket
assemblies on a Pilatus PC-6 were found to be sheared or missing.
Investigation results identified that this was most likely due to
application of too much force to the ends of the horizontal
stabilizer during ground handling.
This condition, if not detected and corrected, could lead to
failure of the primary horizontal stabilizer load path and
consequent separation of the horizontal stabilizer, possibly
resulting in loss of control of the aeroplane.
To address this potential unsafe condition, Pilatus Aircraft Ltd
issued the SB [service bulletin] to provide applicable inspection
For the reasons described above, this [EASA] AD requires a one-
time inspection of the affected parts and the horizontal stabilizer
front spar attachment area and, depending on findings,
accomplishment of applicable corrective action(s). This [EASA] AD
also requires, before installation, inspection of, and, depending on
findings, corrective action(s) on, affected parts held as spare.
The amount of force to the ends of the horizontal stabilizer cannot
be quantified; however, fleet experience shows that repetitive pushing
or pulling on the horizontal stabilizer to move the airplane on the
ground can overload the rivets. Although a root cause could not be
determined, due to the severity of separation of a horizontal
stabilizer, EASA determined that the corrective actions should be
required for other airplanes of the same type design.
Pilatus Aircraft Ltd. had previously considered the small size of
the original "DO NOT PUSH" markings and the significant chance of the
markings being over-sprayed during a respray. As a result, Pilatus
Aircraft Ltd. issued a service bulletin to specify replacing the
smaller markings with new, larger placards. The FAA proposes to require
these placards in the NPRM.
You may examine the MCAI on the internet at http://www.regulations.gov
by searching for and locating Docket No. FAA-2018-1058.
Related Service Information Under 1 CFR Part 51
Pilatus Aircraft Ltd. has issued PC-6 Service Bulletin No. 55-004,
dated July 2, 2018. The service information contains procedures for
inspecting the left-hand and right-hand horizontal stabilizer hinge
bracket assemblies and, if any discrepancies are found, repairing or
replacing any damaged rivets and screws. Pilatus Aircraft Ltd. has also
issued PC-6 Service Bulletin No. 55-002, Revision. No. 1, dated
February 18, 2016. This service information contains procedures for
inspecting and repairing the horizontal stabilizer attachment hardware
and installing four "DO NOT PUSH" placards. 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.
FAA's Determination and Requirements of the Proposed AD
This product has been approved by the aviation authority of another
country, and is approved for operation in the United States. Pursuant
to our bilateral agreement with this State of Design Authority, they
have notified us of the unsafe condition described in the MCAI and
service information referenced above. We are proposing this AD because
we evaluated all information and determined the unsafe condition exists
and is likely to exist or develop on other products of the same type
We have reviewed the MCAI and, in general, agree with the
substance. The MCAI AD does not require installing "DO NOT PUSH"
placards. We have added that requirement to this proposed AD.
Costs of Compliance
We estimate that this proposed AD would affect 30 products of U.S.
registry. We also estimate that it would take about 9 work-hours per
product to comply with the inspection and placard requirements of this
proposed AD. The average labor rate is $85 per work-hour. Required parts
would cost about $200 per product.
Based on these figures, we estimate the cost of the proposed
inspection and placard requirements on U.S. operators to be $28,950, or
$965 per product.
In addition, we estimate the following to do any necessary follow-
on actions: Each rivet replacement would take 2 work-hours, fastener
replacement would take 3 work-hours, one hinge bracket assembly
replacement would take 9 work-hours, and two hinge bracket assembly
replacements would take 15 work-hours. The total estimated cost of
parts would be $10,000. We have no way of determining the number of
products that may need replacement.
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
This AD is issued in accordance with authority delegated by the
Executive Director, Aircraft Certification Service, as authorized by
FAA Order 8000.51C. In accordance with that order, issuance of ADs is
normally a function of the Compliance and Airworthiness Division, but
during this transition period, the Executive Director has delegated the
authority to issue ADs applicable to small airplanes, gliders,
balloons, airships, domestic business jet transport airplanes, and
associated appliances to the Director of the Policy and Innovation
We determined that this proposed AD would not have federalism
implications under Executive Order 13132. This proposed AD would 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
(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
The Proposed Amendment
Accordingly, under the authority delegated to me by the
Administrator, the FAA proposes to amend 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