[Federal Register Volume 67, Number 154 (Friday, August 9, 2002)]
[Proposed Rules]
[Pages 51794-51797]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 02-20136]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2002-CE-28-AD]
RIN 2120-AA64


Airworthiness Directives; PILATUS Aircraft Ltd. Model PC-7 
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 certain PILATUS Aircraft Ltd. (Pilatus) Model 
PC-7 airplanes. This proposed AD would require you to repetitively 
inspect the main landing gear front attachment brackets for cracks, 
and, if cracks are found, install improved-design brackets. Installing 
the improved-design brackets terminates the required inspections. This 
proposed AD is the result of mandatory continuing airworthiness 
information (MCAI) issued by the airworthiness authority for 
Switzerland. The actions specified by this proposed AD are intended to 
detect and correct cracks in the main landing gear front attachment 
brackets, which could result in failure of the brackets. Such failure 
could lead to the main landing gear leg detaching from the wing main 
spar.

DATES: The Federal Aviation Administration (FAA) must receive any 
comments on this proposed rule on or before September 20, 2002.

ADDRESSES: Submit comments to FAA, Central Region, Office of the 
Regional Counsel, Attention: Rules Docket No. 2002-CE-28-AD, 901 
Locust, Room 506, Kansas City, Missouri 64106. You may view any 
comments at this location between 8 a.m. and 4 p.m., Monday through 
Friday, except Federal holidays. You may also send comments 
electronically to the following address: [email protected]. 
Comments sent electronically must contain ``Docket No. 2002-CE-28-AD'' 
in the subject line. If you send comments electronically as attached 
electronic files, the files must be formatted in Microsoft Word 97 for 
Windows or ASCII text.
    You may get service information that applies to this proposed AD 
from Pilatus Aircraft Ltd., Customer Liaison Manager, CH-6371 Stans, 
Switzerland; telephone: +41 41 619 63 19; facsimile: +41 41 619 6224; 
or from Pilatus Business Aircraft Ltd., Product Support Department, 
11755 Airport Way, Broomfield, Colorado 80021; telephone: (303) 465-
9099; facsimile: (303) 465-6040. You may also view this information at 
the Rules Docket at the address above.

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

SUPPLEMENTARY INFORMATION:

Comments Invited

How Do I Comment on This 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 to the 
address specified under the caption ADDRESSES. We will consider all 
comments received on or before the closing date. We may amend this 
proposed rule in light of comments received. Factual information that 
supports your ideas and suggestions is extremely helpful in evaluating 
the effectiveness of this proposed AD action and determining whether we 
need to take additional rulemaking action.

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

    The FAA specifically invites comments on the overall regulatory, 
economic, environmental, and energy aspects of this proposed rule that 
might suggest a need to modify the rule.
    You may view 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 contact we have with the public that 
concerns the substantive parts of this proposed AD.

How Can I Be Sure FAA Receives My Comment?

    If you want FAA to acknowledge the receipt of your mailed comments, 
you must include a self-addressed, stamped postcard. On the postcard, 
write ``Comments to Docket No. 2002-CE-28-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 FAA that an 
unsafe condition may exist on certain Pilatus Model PC-7 airplanes. The 
FOCA reports that an operator of a similar aircraft type design, which 
uses identical main landing gear support brackets, reported a single 
crack in one bracket. A fleet inspection of the operator's aircraft 
revealed stress corrosion cracking in more than 20 aircraft.

What Are the Consequences if the Condition Is Not Corrected?

    Cracks in the main landing gear front attachment brackets could 
result in failure of the brackets. Such failure could lead to the main 
landing gear leg detaching from the wing main spar.

Is There Service Information That Applies to This Subject?

    Pilatus has issued:

--Pilatus PC-7 Service Bulletin No. 57-004, Revision No. 1, dated June 
17, 2002;

[[Page 51795]]

--Pilatus PC-7 Service Bulletin No. 57-005, dated September 10, 2001; 
and
--Pilatus PC-7 Maintenance Manual, Temporary Revision No. 05-10, dated 
September 10, 2001.

What Are The Provisions of This Service Information?

    The service information includes procedures for:

--inspection of the main landing gear front attachment brackets; and
--replacement of the main landing gear front attachment bracket.

What Action Did the FOCA Take?

    The FOCA classified this service information as mandatory and 
issued Swiss AD Number HB 2002-270, dated June 24, 2002, in order to 
ensure the continued airworthiness of these airplanes in Switzerland.

Was This in Accordance With the Bilateral Airworthiness Agreement?

    These airplane models are manufactured in Switzerland and are 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 
This 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-7 airplanes of the same type design 
that are on the U.S. registry;
--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 This 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 This Proposed AD Impact?

    We estimate that this proposed AD affects 14 airplanes in the U.S. 
registry.

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

    We estimate the following costs to accomplish each proposed 
inspection:

----------------------------------------------------------------------------------------------------------------
                                                                              Total cost per  Total cost on U.S.
                Labor cost                             Parts cost                airplane          operators
----------------------------------------------------------------------------------------------------------------
4 workhours  x  $60 = $240...............  No parts required................            $240       $240  x  14 =
                                                                                                         $3,360.
----------------------------------------------------------------------------------------------------------------

    The FAA has no method of determining the number of repetitive 
inspections each owner/operator would incur over the life of each of 
the affected airplanes so the cost impact is based on the initial 
inspection.
    We estimate the following costs to accomplish any necessary 
replacements that would be required based on the results of the 
proposed inspection. We have no way of determining the number of 
airplanes that may need such replacement:

----------------------------------------------------------------------------------------------------------------
                      Labor cost                                  Parts cost             Total cost per airplane
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80 workhours  x  $60 = $4,800 per side...............  $2,500 per side.................  $4,800 + $2,500 =
                                                                                          $7,300 per side.
----------------------------------------------------------------------------------------------------------------

Compliance Time of This Proposed AD

What Would Be the Compliance Time of This Proposed AD?

    The compliance time of this proposed AD is whichever occurs later: 
(1) upon the accumulation of 3,000 hours time-in-service (TIS) on the 
attachment brackets or 10 years after installation of the brackets, 
whichever occurs first; or (2) within 90 days after the effective date 
of the proposed AD.

Why Is the Compliance Time of This Proposed AD Presented in Both Hours 
TIS and Calendar Time?

    Cracking of the main landing gear attachment brackets on the 
affected airplanes is caused by stress corrosion, which starts as a 
result of high local stress incurred through operation. Corrosion can 
then develop regardless of whether the airplane is in flight or on the 
ground. The cracks may not be noticed initially as a result of the 
stress loads, but could then progress as a result of corrosion. The 
stress incurred during flight operations or temperature changes could 
then cause rapid crack growth. In order to ensure that these stress 
corrosion cracks do not go undetected, a compliance time of specific 
hours TIS and calendar time is utilized.

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

[[Page 51796]]

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. 2002-CE-28-AD

    (a) What airplanes are affected by this AD? This AD affects 
Model PC-7 airplanes, serial numbers 101 through 618, that are 
certificated in any category.
    (b) Who must comply with this AD? Anyone who wishes to operate 
any of the airplanes identified in paragraph (a) of this AD must 
comply with this AD.
    (c) What problem does this AD address? The actions specified by 
this AD are intended to detect and correct cracks in the main 
landing gear front attachment brackets, which could result in 
failure of the brackets. Such failure could lead to the main landing 
gear leg detaching from the wing main spar.
    (d) What actions must I accomplish to address this problem? To 
address this problem, you must accomplish the following:

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         Compliance                  Actions             Procedures
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(1) Initial Inspection: At    Inspect, using the    In accordance with
 whichever of the following    Impedance-Plane       the ACCOMPLISHMENT
 occurs later, unless          Eddy-Current          INSTRUCTIONS
 already accomplished:         Inspection, both      section of Pilatus
(i) upon the accumulation of   main landing gear     PC-7 Service
 3,000 hours time-in-service   front attachment      Bulletin No. 57-
 (TIS) on the attachment       brackets, part        004, Revision No.
 brackets or 10 years after    number (P/N)          1, dated June 17,
 installation of the           111.34.07.105 and P/  2002; the
 brackets, whichever occurs    N 111.34.07.106 for   ACCOMPLISHMENT
 first; or.                    cracks.               INSTRUCTIONS
(ii) within 90 days after                            section of Pilatus
 the effective date of this                          PC-7 Service
 AD..                                                Bulletin No. 57-
                                                     005, dated
                                                     September 10, 2001;
                                                     and Pilatus PC-7
                                                     Maintenance Manual,
                                                     Temporary Revision
                                                     No. 05-10, dated
                                                     September 10, 2001.
------------------------------------------------------------------------
(2) Repetitive Inspections:   Inspect, using the    In accordance with
 Within 12 calendar months     Impedance-Plane       the ACCOMPLISHMENT
 after the initial             Eddy-Current          INSTRUCTIONS
 inspection required in        Inspection, both      section of Pilatus
 paragraph (d)(1) of this AD   main landing gear     PC-7 Service
 and thereafter at intervals   front attachment      Bulletin No. 57-
 not to exceed 12 calendar     brackets, P/N         004, Revision No.
 months.                       111.34.07.105 and P/  1, dated June 17,
                               N 111.34.07.106 for   2002; the
                               cracks.               ACCOMPLISHMENT
                                                     INSTRUCTIONS
                                                     section of Pilatus
                                                     PC-7 Service
                                                     Bulletin No. 57-
                                                     005, dated
                                                     September 10, 2001;
                                                     and Pilatus PC-7
                                                     Maintenance Manual,
                                                     Temporary Revision
                                                     No. 05-10, dated
                                                     September 10, 2001.
------------------------------------------------------------------------
(3) Prior to further flight   If a crack is found   In accordance with
 after the inspection which    in any main landing   the ACCOMPLISHMENT
 the damage was found.         gear front            INSTRUCTIONS
                               attachment bracket    section of Pilatus
                               during any            PC-7 Service
                               inspection required   Bulletin No. 57-
                               in this AD, replace   005, dated
                               with an improved      September 10, 2001.
                               bracket, P/N
                               557.10.09.045, P/N
                               557.10.09.046, or
                               FAA-approved
                               equivalent P/N.
                               Repetitive
                               inspections are
                               still required on
                               any P/N
                               111.34.07.105 and P/
                               N 111.34.07.106 for
                               cracks.
------------------------------------------------------------------------
(4) At any time terminating   You may terminate     In accordance with
 action for the repetitive     the inspections       ACCOMPLISHMENT
 inspections. However, you     required in           INSTRUCTIONS
 must replace prior to         paragraphs(d)(1)      Pilatus PC-7
 further flight if you find    and (d)(2) of this    Service Bulletin
 cracks during any             AD when improved      No. 57-005, dated
 inspections required by       design main landing   September 10, 2001.
 this AD.                      gear front
                               attachment
                               brackets, P/N
                               557.10.09.045, P/N
                               557.10.09.046, or
                               FAA-approved
                               equivalent P/Ns,
                               are installed on
                               both sides of the
                               airplane.
------------------------------------------------------------------------
(5) As of the effective date  Only install main     Not Applicable.
 of this AD.                   landing gear
                               brackets that are P/
                               N 557.10.09.045, P/
                               N 557.10.09.046, or
                               FAA-approved
                               equivalent P/Ns.
------------------------------------------------------------------------


    Note 1: If you find cracks on one side only, you are only 
required to replace the damaged side with the new improved-design 
bracket and continue the repetitive inspections required by 
paragraph (d)(2) of this AD. Repetitive inspections are still 
required on any installed bracket with either P/N 111.34.07.105 or 
P/N 111.34.07.106.

    (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

[[Page 51797]]

    (2) The Standards Office 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 Standards Office Manager.

    Note 2: 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 Doug Rudolph, Aerospace 
Engineer, FAA, Small Airplane Directorate, 901 Locust, Room 301, 
Kansas City, Missouri 64106; telephone: (816) 329-4059; 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 get copies of the documents referenced in this AD from 
Pilatus Aircraft Ltd., Customer Liaison Manager, CH-6371 Stans, 
Switzerland; telephone: +41 41 619 63 19; facsimile: +41 41 619 
6224; or from Pilatus Business Aircraft Ltd., Product Support 
Department, 11755 Airport Way, Broomfield, Colorado 80021; 
telephone: (303) 465-9099; facsimile: (303) 465-6040. You may view 
these documents at FAA, Central Region, Office of the Regional 
Counsel, 901 Locust, Room 506, Kansas City, Missouri 64106.

    Note 3: The subject of this AD is addressed in Swiss AD HB 2002-
270, dated June 24, 2002.


    Issued in Kansas City, Missouri, on August 2, 2002.
Dorenda D. Baker,
Acting Manager, Small Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 02-20136 Filed 8-8-02; 8:45 am]
BILLING CODE 4910-13-P