[Federal Register Volume 65, Number 213 (Thursday, November 2, 2000)]
[Proposed Rules]
[Pages 65798-65800]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 00-28096]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 99-CE-77-AD]
RIN 2120-AA64


Airworthiness Directives; Pilatus Aircraft LTD Model PC-6 
Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: This document proposes to adopt a new airworthiness directive 
(AD) that would apply to all Pilatus Aircraft LTD (Pilatus) Model PC-6 
airplanes that are equipped with a certain stabilizer trim actuator. 
The proposed AD would 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. The proposed AD is the result 
of mandatory continuing airworthiness information (MCAI) issued by the 
airworthiness authority for Switzerland. The actions specified by the 
proposed 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: The Federal Aviation Administration (FAA) must receive any 
comments on this proposed rule on or before December 8, 2000.

ADDRESSES: Submit comments in triplicate to FAA, Central Region, Office 
of the Regional Counsel, Attention: Rules Docket No. 99-CE-77-AD, 901 
Locust, Room 506, Kansas City, Missouri 64106. Comments may be 
inspected at this location between 8 a.m. and 4 p.m., Monday through 
Friday, holidays excepted.
    Service information that applies to the proposed AD may be obtained 
from Pilatus Aircraft Ltd., Customer Liaison Manager, CH-6371 Stans, 
Switzerland; telephone: +41 41 619 65 09; facsimile: +41 41 610 33 51. 
This information also may be examined at the Rules Docket at the 
address above.

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:

Comments Invited

How Do I Comment on the Proposed AD?

    The FAA invites comments on this proposed rule. You may submit 
whatever written data, views, or arguments you choose. You need to 
include the rule's docket number and submit your comments in triplicate 
to the address specified under the caption ADDRESSES. The FAA will 
consider all comments received on or before the closing date. We may 
amend the proposed rule in light of comments received. Factual 
information that supports your ideas and suggestions is extremely 
helpful in evaluating the effectiveness of the proposed AD action and 
determining whether we need to take additional rulemaking action.

Are There Any Specific Portions of the Proposed AD I Should Pay 
Attention To?

    The FAA specifically invites comments on the overall regulatory, 
economic, environmental, and energy aspects of the proposed rule that 
might suggest a need to modify the rule. You may examine all comments 
we receive before and after the closing date of the rule in the Rules 
Docket. We will file a report in the Rules Docket that summarizes each 
FAA contact with the public that concerns the substantive parts of the 
proposed AD.
    We are re-examining the writing style we currently use in 
regulatory documents, in response to the Presidential memorandum of 
June 1, 1998. That memorandum requires federal agencies to communicate 
more clearly with the public. We are interested in your comments on 
whether the style of this document is clearer, and any other 
suggestions you might have to improve the clarity of FAA communications 
that affect you. You can get more information about the Presidential 
memorandum and the plain language initiative at http://www.plainlanguage.gov. 

How Can I Be Sure FAA Receives My Comment?

    If you want us to acknowledge the receipt of your comments, you 
must include a self-addressed, stamped postcard. On the postcard, write 
``Comments to Docket No. 99-CE-77-AD.'' We will date stamp and mail the 
postcard back to you.

Discussion

What Events Have Caused This Proposed 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 stabilizer trim actuator with 
consequent loss of control of the airplane.

Is There Service Information That Applies to This Subject?

    Pilatus has issued Service Bulletin No. 178, dated September 29, 
1999.

What Are the Provisions of This Service Bulletin?

    The service bulletin:

--includes procedures for inspecting the lower lug of the actuator for 
cracks, damage, or distortion, and assuring that the staked bearing is 
correctly installed in the bore of the lug; and
--specifies repairing any cracked, damaged, or distorted parts, as 
necessary, and reassembling any incorrectly installed staked bearing.

What Action Did the FOCA Take?

    The FOCA classified this service bulletin as mandatory and issued 
Swiss AD HB 99-507, dated October 1, 1999, in order to assure the 
continued airworthiness of these airplanes in Switzerland.

[[Page 65799]]

Was This in Accordance With the Bilateral Airworthiness Agreement?

    This airplane model is manufactured in Switzerland and is type 
certificated for operation in the United States under the provisions of 
section 21.29 of the Federal Aviation Regulations (14 CFR 21.29) and 
the applicable bilateral airworthiness agreement.
    Pursuant to this bilateral airworthiness agreement, the FOCA has 
kept FAA informed of the situation described above.

The FAA's Determination and an Explanation of the Provisions of the 
Proposed AD

What Has FAA Decided?

    The FAA has examined the findings of the FOCA; reviewed all 
available information, including the service information referenced 
above; and determined that:
--the unsafe condition referenced in this document exists or could 
develop on other Pilatus Model PC-6 airplanes of the same type design 
that are equipped with one of the previously referenced stabilizer trim 
actuators;
--the actions specified in the previously-referenced service 
information should be accomplished on the affected airplanes; and
--AD action should be taken in order to correct this unsafe condition.

What Would the Proposed AD Require?

    This proposed AD would require you to incorporate the actions in 
the previously referenced service bulletin.

Cost Impact

How Many Airplanes Would the Proposed AD Impact?

    We estimate that the proposed AD affects 7 airplanes in the U.S. 
registry.

What Would Be the Cost Impact of the Proposed AD on Owners/Operators of 
the Affected Airplanes?

    We estimate the following costs to accomplish the proposed 
inspection:

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

    If any distortion, damage, or cracks are found during the proposed 
inspection, you would 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 would cost since the damage to each airplane would be 
unique.

Regulatory Impact

Would This Proposed AD Impact Various Entities?

    The regulations proposed herein 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. Therefore, it 
is determined that this proposed rule would not have federalism 
implications under Executive Order 13132.

Would This Proposed AD Involve a Significant Rule or Regulatory Action?

    For the reasons discussed above, I certify that this proposed 
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) if 
promulgated, 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 draft regulatory 
evaluation prepared for this action has been placed 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, Safety.

The Proposed Amendment

    Accordingly, under the authority delegated to me by the 
Administrator, the Federal Aviation Administration proposes to amend 
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 airworthiness directive 
(AD) to read as follows:

Pilatus Aircraft Ltd.: 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 the  Upon accumulating   Accomplish the
 actuator for cracks, damage, or   500 hours time-in-  inspection in
 distortion, and assure that the   service on the      accordance with
 staked bearing is correctly       airplane or         the
 installed in the bore of the      within the next     ACCOMPLISHMENT
 lug.                              100 hours TIS       INSTRUCTIONS
                                   after the           section of
                                   effective date of   Pilatus Service
                                   this AD,            Bulletin No. 178,
                                   whichever occurs    dated September
                                   later, unless       29, 1999.
                                   already
                                   accomplished.

[[Page 65800]]

 
(2) Repair any cracked, damaged,  Prior to further    Accomplish any
 or distorted parts, as            flight after the    repairs in
 necessary, and reassemble any     inspection          accordance with
 incorrectly installed staked      required by         an FAA-approved
 bearing.                          paragraph (d)(1)    repair scheme
                                   of this AD.         obtained from the
                                                       manufacturer.
                                                       Accomplish the
                                                       reassembly in
                                                       accordance with
                                                       the instructions
                                                       in the
                                                       maintenance
                                                       manual.
------------------------------------------------------------------------

    (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) How do I get copies of the documents referenced in this AD? 
You may obtain copies of the documents 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 these documents at FAA, Central Region, Office 
of the Regional Counsel, 901 Locust, Room 506, Kansas City, Missouri 
64106.

    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 October 26, 2000.
Michael Gallagher,
Manager, Small Airplane Directorate, Aircraft Certfication Service.
[FR Doc. 00-28096 Filed 11-1-00; 8:45 am]
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