Airworthiness Directives; Pilatus Aircraft LTD Model PC-6 Airplanes

[Federal Register Volume 66, Number 19 (Monday, January 29, 2001)]
[Rules and Regulations]
[Pages 8079-8081]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 01-2002]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 99-CE-77-AD; Amendment 39-12088; AD 2001-02-04]
RIN 2120-AA64


Airworthiness Directives; Pilatus Aircraft LTD Model PC-6 
Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule.

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SUMMARY: This amendment adopts a new airworthiness directive (AD) that 
applies to all Pilatus Aircraft LTD (Pilatus) Model PC-6 airplanes that 
are equipped with a certain stabilizer trim actuator. This AD requires 
you to inspect the lower lug of the actuator for cracks, damage, or 
distortion; verify that the staked bearing is correctly installed in 
the bore of the lug; and repair any cracked, damaged, or distorted 
parts and reassemble any incorrectly installed staked bearing, as 
necessary. This AD is the result of mandatory continuing airworthiness 
information (MCAI) issued by the airworthiness authority for 
Switzerland. The actions specified by this AD are intended to detect 
and correct damage, distortion, or cracks in the lower lug assembly, 
which could result in failure of the lower lug. Such failure could lead 
to loss of the stabilizer trim actuator with consequent loss of control 
of the airplane.

DATES: This AD becomes effective on March 13, 2001.
    The Director of the Federal Register approved the incorporation by 
reference of certain publications listed in the regulations as of March 
13, 2001.

ADDRESSES: You may get the service information referenced in this AD 
from Pilatus Aircraft Ltd., Customer Liaison Manager, CH-6371 Stans, 
Switzerland; telephone: +41 41 619 65 09; facsimile: +41 41 610 33 51. 
You may examine this information at the Federal Aviation Administration 
(FAA), Central Region, Office of the Regional Counsel, Attention: Rules 
Docket No. 99-CE-77-AD, 901 Locust, Room 506, Kansas City, Missouri 
64106; or at the Office of the Federal Register, 800 North Capitol 
Street, NW., suite 700, Washington, DC.

FOR FURTHER INFORMATION CONTACT: Roman T. Gabrys, Aerospace Engineer, 
FAA, Small Airplane Directorate, 901 Locust, Room 301, Kansas City, 
Missouri 64106; telephone: (816) 329-4141; facsimile: (816) 329-4090.

SUPPLEMENTARY INFORMATION:

Discussion

    What events have caused this AD? The Federal Office for Civil 
Aviation (FOCA), which is the airworthiness authority for Switzerland, 
recently notified the FAA that an unsafe condition may exist on all 
Pilatus Model PC-6 airplanes that are equipped with a stabilizer trim 
actuator, part number (P/N) 978.73.18.101, 978.73.18.102, or 
978.73.18.103 (Electomech P/N EM 483-1, 483-2, or 483-3). The FOCA 
reports an incident of a cracked, damaged, and distorted lower lug of 
the horizontal stabilizer trim actuator. Analysis of this incident 
reveals that the staked bearing was loose, which caused excessive wear 
and failure of the actuator lower lug.
    What are the consequences if the condition is not corrected? 
Damage, distortion, or cracks in the lower lug assembly, if not 
detected and corrected, could result in failure of this part. Such 
failure could lead to loss of the

[[Page 8080]]

stabilizer trim actuator with consequent loss of control of the 
airplane.
    Has FAA taken any action to this point? We issued a proposal to 
amend part 39 of the Federal Aviation Regulations (14 CFR part 39) to 
include an AD that would apply to all Pilatus Model PC-6 airplanes that 
are equipped with a certain stabilizer trim actuator. This proposal was 
published in the Federal Register as a notice of proposed rulemaking 
(NPRM) on November 2, 2000 (65 FR 65789). The NPRM proposed to require 
you to inspect the lower lug of the actuator for cracks, damage, or 
distortion; verify that the staked bearing is correctly installed in 
the bore of the lug; and repair any cracked, damaged, or distorted 
parts and reassemble any incorrectly installed staked bearing, as 
necessary.
    Was the public invited to comment? Interested persons were afforded 
an opportunity to participate in the making of this amendment. No 
comments were received on the proposed rule or the FAA's determination 
of the cost to the public.

The FAA's Determination

    What is FAA's final determination on this issue? After careful 
review of all available information related to the subject presented 
above, we have determined that air safety and the public interest 
require the adoption of the rule as proposed except for minor editorial 
corrections. We determined that these minor corrections:

--Will not change the meaning of the AD; and
--Will not add any additional burden upon the public than was already 
proposed.

Cost Impact

    How many airplanes does this AD impact? We estimate that this AD 
affects 7 airplanes in the U.S. registry.
    What is the cost impact of this AD on owners/operators of the 
affected airplanes? We estimate the following costs to accomplish the 
inspection :

----------------------------------------------------------------------------------------------------------------
                                                                Total cost per      Total cost on U.S. airplane
             Labor cost                    Parts cost              airplane                  operators
----------------------------------------------------------------------------------------------------------------
1 workhour  x  $60 per hour = $60..  Not applicable.......  $60 per airplane.....  $60  x  7=$420.
----------------------------------------------------------------------------------------------------------------

    If any distortion, damage, or cracks are found during the 
inspection, you will have to repair the actuator assembly in accordance 
with an FAA-approved repair scheme developed by the manufacturer. The 
FAA has no way of determining how much incorporating each repair scheme 
will cost since the damage to each airplane will be unique.

Regulatory Impact

    Does this AD impact various entities? The regulations adopted 
herein 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. Therefore, it is determined that this final rule does not 
have federalism implications under Executive Order 13132.
    Does this AD involve a significant rule or regulatory action? For 
the reasons discussed above, I certify that this action (1) is not a 
``significant regulatory action'' under Executive Order 12866; (2) is 
not a ``significant rule'' under DOT Regulatory Policies and Procedures 
(44 FR 11034, February 26, 1979); and (3) 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. A copy 
of the final evaluation prepared for this action is contained in the 
Rules Docket. A copy of it may be obtained by contacting the Rules 
Docket at the location provided under the caption ADDRESSES.

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 Federal Aviation Administration amends part 39 of 
the Federal Aviation Regulations (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. FAA amends Sec. 39.13 by adding a new AD to read as follows:

2001-02-04  Pilatus Aircraft Ltd.: Amendment 39-12088; Docket No. 
99-CE-77-AD.

    (a) What airplanes are affected by this AD? This AD affects 
Model PC-6 airplanes, all serial numbers, that are:
    (1) Certificated in any category; and
    (2) Equipped with a stabilizer trim actuator, part number (P/N) 
978.73.18.101, 978.73.18.102, or 978.73.18.103 (Electomech P/N EM 
483-1, 483-2, or 483-3), or FAA-approved equivalent part number.
    (b) Who must comply with this AD? Anyone who wishes to operate 
any of the above airplanes must comply with this AD.
    (c) What problem does this AD address? The actions specified by 
this AD are intended to detect and correct damage, distortion, or 
cracks in the lower lug assembly, which could result in failure of 
the lower lug. Such failure could lead to loss of the stabilizer 
trim actuator with consequent loss of control of the airplane.
    (d) What actions must I accomplish to address this problem? To 
address this problem, you must accomplish the following:

------------------------------------------------------------------------
           Action                Compliance time         Procedures
------------------------------------------------------------------------
(1) Inspect the lower lug of  Upon accumulating     Accomplish the
 the actuator for cracks,      500 hours time-in-    inspection in
 damage, or distortion, and    service (TIS) on      accordance with the
 assure that the staked        the airplane or       ACCOMPLISHMENT
 bearing is correctly          within the next 100   INSTRUCTIONS
 installed in the bore of      hours TIS after       section of Pilatus
 the lug.                      March 13, 2001 (the   Service Bulletin
                               effective date of     No. 178, dated
                               this AD), whichever   September 29, 1999.
                               occurs later,
                               unless already
                               accomplished.
(2) Repair any cracked,       Prior to further      Accomplish any
 damaged, or distorted         flight after the      repairs in
 parts, as necessary, and      inspection required   accordance with an
 reassemble any incorrectly    by paragraph (d)(1)   FAA-approved repair
 installed staked bearing.     of this AD.           scheme obtained
                                                     from the
                                                     manufacturer.
                                                     Accomplish the
                                                     reassembly in
                                                     accordance with the
                                                     instructions in the
                                                     maintenance manual.
------------------------------------------------------------------------


[[Page 8081]]

    (e) Can I comply with this AD in any other way? You may use an 
alternative method of compliance or adjust the compliance time if:
    (1) Your alternative method of compliance provides an equivalent 
level of safety; and
    (2) The Manager, Small Airplane Directorate, approves your 
alternative. Submit your request through an FAA Principal 
Maintenance Inspector, who may add comments and then send it to the 
Manager, Small Airplane Directorate.

    Note 1: This AD applies to each airplane identified in paragraph 
(a) of this AD, regardless of whether it has been modified, altered, 
or repaired in the area subject to the requirements of this AD. For 
airplanes that have been modified, altered, or repaired so that the 
performance of the requirements of this AD is affected, the owner/
operator must request approval for an alternative method of 
compliance in accordance with paragraph (e) of this AD. The request 
should include an assessment of the effect of the modification, 
alteration, or repair on the unsafe condition addressed by this AD; 
and, if you have not eliminated the unsafe condition, specific 
actions you propose to address it.

    (f) Where can I get information about any already approved 
alternative methods of compliance? Contact Roman T. Gabrys, 
Aerospace Engineer, FAA, Small Airplane Directorate, 901 Locust, 
Room 301, Kansas City, Missouri 64106; telephone: (816) 329-4141; 
facsimile: (816) 329-4090.
    (g) What if I need to fly the airplane to another location to 
comply with this AD? The FAA can issue a special flight permit under 
sections 21.197 and 21.199 of the Federal Aviation Regulations (14 
CFR 21.197 and 21.199) to operate your airplane to a location where 
you can accomplish the requirements of this AD.
    (h) Are any service bulletins incorporated into this AD by 
reference? Actions required by this AD must be done in accordance 
with Pilatus Service Bulletin No. 178, dated September 29, 1999. The 
Director of the Federal Register approved this incorporation by 
reference under 5 U.S.C. 552(a) and 1 CFR part 51. You can get 
copies from Pilatus Aircraft Ltd., Customer Liaison Manager, CH-6371 
Stans, Switzerland. You can look at copies at the FAA, Central 
Region, Office of the Regional Counsel, 901 Locust, Room 506, Kansas 
City, Missouri, or at the Office of the Federal Register, 800 North 
Capitol Street, NW., suite 700, Washington, DC.
    (i) When does this amendment become effective? This amendment 
becomes effective on March 13, 2001.

    Note 2: The subject of this AD is addressed in Swiss AD HB 99-
507, dated October 1, 1999.


    Issued in Kansas City, Missouri, on January 12, 2001.
Michael Gallagher,
Manager, Small Airplane Directorate, Aircraft Certification Service.
[FR Doc. 01-2002 Filed 1-26-01; 8:45 am]
BILLING CODE 4910-13-P

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