[Federal Register Volume 71, Number 75 (Wednesday, April 19, 2006)]
[Rules and Regulations]
[Pages 19998-20001]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 06-3725]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2004-19220; Directorate Identifier 2004-CE-27-AD; 
Amendment 39-14568; AD 2006-08-11]
RIN 2120-AA64


Airworthiness Directives; Pilatus Aircraft Ltd. Models PC-12 and 
PC-12/45 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 all 
Pilatus Aircraft Ltd. Models PC-12 and PC-12/45 airplanes equipped with 
certain crew seat bucket assemblies with and without a backrest recline 
system. This AD requires you to replace the backrest tubes on these 
crew seat bucket assemblies at a specified time and adds a life limit 
for these backrest tubes. This AD results from mandatory continuing 
airworthiness information (MCAI) issued by the airworthiness authority 
for Switzerland. We are issuing this AD to prevent cracks in the 
backrest tubes of certain crew seat bucket assemblies, which could 
result in failure of the seat system. This failure could lead to the 
pilot and co-pilot's reduced ability to control the airplane. This 
failure could also affect the proper function of the seat restrain 
system in the case of an emergency landing.

DATES: This AD becomes effective on June 2, 2006.

ADDRESSES: For information identified in this AD, contact Pilatus 
Aircraft Ltd., Customer Support Manager, CH-6371 Stans, Switzerland; 
telephone: +41 41 619 6208; fax: +41 41 619 7311; or Pilatus Business 
Aircraft Ltd., Product Support Department, 11755 Airport Way, 
Broomfield, Colorado 80021; telephone: (303) 465-9099; fax: (303) 465-
6040.
    To view the AD docket, go to the Docket Management Facility, U.S. 
Department of Transportation, 400 Seventh Street, SW., Nassif Building, 
Room PL-401, Washington, DC 20590-0001 or on the Internet at http://dms.dot.gov. The docket number is FAA-2004-19220; Directorate 
Identifier 2004-CE-27-AD.

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.

SUPPLEMENTARY INFORMATION:

Discussion

    On February 7, 2006, we issued a proposal to amend part 39 of the 
Federal Aviation Regulations (14 CFR part 39) to include an 
airworthiness directive (AD) that would apply to all Pilatus Aircraft 
Ltd. (Pilatus) Models PC-12 and PC-12/45 airplanes equipped with 
certain crew seat bucket assemblies with and without a backrest recline 
system. This proposal

[[Page 19999]]

was published in the Federal Register as a notice of proposed 
rulemaking (NPRM) on February 14, 2006 (71 FR 7698). The NPRM proposed 
to require you to replace the backrest tubes on certain crew seat 
bucket assemblies at a specified time and add a life limit for the 
backrest tubes.

Comments

    We provided the public the opportunity to participate in developing 
this AD. The following presents the comments received on the proposal 
and FAA's response to each comment:

Comment Issue No. 1: Remove Reference to PC12 Maintenance Manual 
Temporary Revision No. 04-13, Dated June 15, 2005

    The manufacturer states that PC-12 Interactive Electronic Technical 
Publication (IETP) Revision 9 (which will include Aircraft Maintenance 
Manual (AMM) Revision 17) will supersede PC12 Maintenance Manual 
Temporary Revision No. 04-13, dated June 15, 2005, by March 31, 2006, 
by incorporating the information into the IETP.
    The commenter requests to remove the reference to PC12 Maintenance 
Manual Temporary Revision No. 04-13, dated June 15, 2005, from the 
final rule AD action.
    We agree with the commenter and will change the final rule AD 
action.

Comment Issue No. 2: Change the Compliance Time for Replacing Certain 
Crew Seat Bucket Assemblies

    The manufacturer states the life limit and the compliance time for 
replacing crew seat bucket assemblies without a recline system, part 
numbers (P/Ns) 959.30.01.131, 959.30.01.132, 959.30.01.133, and 
959.30.01.134 (or FAA-approved equivalent P/Ns), is too conservative. 
The manufacturer states there have not been any of these seats found 
with cracks and they have confidence the life limit could be increased 
from 10,000 hours time-in-service (TIS) to 12,163 hours TIS.
    The manufacturer requests the compliance time for initial 
replacement be increased from ``upon the accumulation of 10,000 TIS or 
within the next 100 hours TIS after the effective date of the AD, 
whichever occurs later,'' to ``upon the accumulation of 10,000 TIS or 
within the next 500 hours TIS after the effective date of the AD, 
whichever occurs later.''
    We partially agree with the commenter. Since there have not been 
any reported cracks on the above referenced crew seat bucket assemblies 
and there is confidence from the manufacturer that there is a 2,163-
hour TIS ``cushion,'' we agree that increasing the threshold compliance 
time from 100 hours TIS to 500 hours TIS can be done without 
compromising the safety of crew seat bucket assemblies with 10,000 
hours or less TIS. For crew seat bucket assemblies with more than 
10,000 hours TIS, we have established a compliance time for initial 
replacement of 100 hours TIS or upon the accumulation of 10,500 hours 
TIS, whichever occurs later.
    We will change the final rule AD action to reflect this change.

Conclusion

    We have carefully reviewed the available data and determined that 
air safety and the public interest require adopting the AD as proposed 
except for incorporating the concerns addressed by the commenter and 
minor editorial corrections. We have determined that we should 
incorporate the concerns addressed by the commenter, and that these 
minor changes:

--Are consistent with the intent that was proposed in the NPRM for 
correcting the unsafe condition; and
--Do not add any additional burden upon the public than was already 
proposed in the NPRM.

Cost of Compliance

    We estimate that this AD affects 260 airplanes in the U.S. 
registry.
    We estimate the following costs to do the replacement:

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                                                                                            Total cost on U.S.
              Labor cost                      Parts cost        Total cost per airplane         operators
----------------------------------------------------------------------------------------------------------------
3 workhours x $65 per hour = $195 per  $600 per seat bucket     $195 + $600 = $795 per   $795 per seat bucket
 seat bucket assembly.                  assembly. 2 seats on     seat bucket assembly.    assembly x 2 per
                                        each airplane.                                    airplane = $1,590.
                                                                                          $1,590 x 260 =
                                                                                          $413,400.
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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 AD.

Regulatory Findings

    We have 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 that 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); 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.
    We prepared a summary of the costs to comply with this AD (and 
other information as included in the Regulatory Evaluation) and placed 
it in the AD Docket. You may get a copy of this summary by sending a 
request to us at the address listed under ADDRESSES. Include ``Docket 
No. FAA-2004-19220; Directorate Identifier 2004-CE-27-AD'' in your 
request.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Safety.

Adoption of the Amendment

0
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

0
1. The authority citation for part 39 continues to read as follows:


[[Page 20000]]


    Authority: 49 U.S.C. 106(g), 40113, 44701.


Sec.  39.13  [Amended]

0
2. FAA amends Sec.  39.13 by adding the following new AD:

2006-08-11 Pilatus Aircraft Ltd.: Amendment 39-14568; Docket No. 
FAA-2004-19220; Directorate Identifier 2004-CE-27-AD.

Effective Date

    (a) This AD becomes effective on June 2, 2006.

Affected ADs

    (b) None.

Applicability

    (c) This AD affects Models PC-12 and PC-12/45 airplanes, all 
serial numbers, that are equipped with the following crew seat 
bucket assemblies and are certificated in any category:
    (1) Crew seats with a recline system, part numbers (P/N): 
959.30.01.111, 959.30.01.112, 959.30.01.121, and 959.30.01.122
    (2) Crew seats without recline system, P/Ns: 959.30.01.131, 
959.30.01.132, 959.30.01.133, and 959.30.01.134

Unsafe Condition

    (d) This AD is the result of mandatory continuing airworthiness 
information (MCAI) issued by the airworthiness authority for 
Switzerland. The actions specified in this AD are intended to 
prevent cracks in the backrest tubes of certain crew seat bucket 
assemblies, which could result in failure of the seat system. This 
failure could lead to the pilot and co-pilot's reduced ability to 
control the airplane. This failure could also affect the proper 
function of the seat restrain system in the case of an emergency 
landing.

Compliance

    (e) To address this problem, you must do the following:

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            Actions                   Compliance           Procedures
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(1) For crew seat bucket        Initially replace upon  Replace
 assemblies with a recline       the accumulation of     following the
 system, P/Ns 959.30.01.111,     5,000 hours time-in-    procedures in
 959.30.01.112, 959.30.01.121,   service (TIS) or        the applicable
 and 959.30.01.122 (or FAA-      within the next 100     component
 approved equivalent P/Ns),      hours TIS after June    maintenance
 replace the backrest tubes.     2, 2006 (the            manual (CMM).
                                 effective date of
                                 this AD), whichever
                                 occurs later, unless
                                 already done.
                                 Thereafter, replace
                                 the backrest tubes
                                 upon the accumulation
                                 of 5,000 hours TIS
                                 (the life limit
                                 established in this
                                 AD).
(2) For crew seat bucket        Initially replace upon  Replace
 assemblies without a recline    the accumulation of     following the
 system, P/Ns 959.30.01.131,     10,000 hours TIS or     procedures in
 959.30.01.132, 959.30.01.133,   within the next 500     the CMM.
 and 959.30.01.134 (or FAA-      hours TIS after June
 approved equivalent P/Ns),      2, 2006 (the
 and with less than or equal     effective date of
 to 10,000 hours TIS replace     this AD), whichever
 the backrest tubes.             occurs later, unless
                                 already done.
                                 Thereafter, replace
                                 the backrest tubes
                                 upon the accumulation
                                 of 10,000 hours TIS
                                 (the life limit
                                 established in this
                                 AD).
(3) For crew seat bucket        Initially upon the      Replace
 assemblies without a recline    accumulation of         following the
 system, P/Ns 959.30.01.131,     10,500 hours TIS or     procedures in
 959.30.01.132, 959.30.01.133,   within the next 100     the CMM.
 and 959.30.01.134 (or FAA-      hours TIS after June
 approved equivalent P/Ns),      2, 2006 (the
 and with greater than 10,000    effective date of
 hours TIS replace the           this AD), whichever
 backrest tubes.                 occurs later, unless
                                 already done.
                                 Thereafter, replace
                                 the backrest tubes
                                 upon the accumulation
                                 of 10,000 hours TIS
                                 (the life limit
                                 established in this
                                 AD).
(4) Do not install:...........  As of June 2, 2006      Not applicable.
                                 (the effective date
                                 of this AD). The life
                                 limits specified in
                                 paragraphs (e)(1),
                                 (e)(2), and (e)(3) of
                                 this AD apply to all
                                 parts installed as
                                 spares.
    (i) Any crew seat bucket
     assembly with a recline
     system, P/N
     959.30.01.111,
     959.30.01.112,
     959.30.01.121, and
     959.30.01.122, (or FAA-
     approved equivalent P/
     Ns), with unknown hours
     TIS or which has
     accumulated 5,000 or more
     hours TIS; or
    (ii) Any crew seat bucket
     assembly without a
     recline system, P/N
     959.30.01.131,
     959.30.01.132,
     959.30.01.133, and
     959.30.01.134 (or FAA-
     approved equivalent P/
     Ns), with unknown hours
     TIS or which has
     accumulated 10,000 or
     more hours TIS.
(5) 14 CFR 21.303 allows for    Not applicable........  Not applicable.
 replacement parts through
 parts manufacturer
 approval(PMA). The phrase
 ``or FAA-approved equivalent
 part number'' in this AD is
 intended to signify those
 parts that are PMA parts
 approved through identicality
 to the design of the part
 under the type certificate
 and replacement parts to
 correct the unsafe condition
 under PMA (other than
 identicality). If parts are
 installed that are identical
 to the unsafe parts, then the
 corrective actions of the AD
 affect these parts also. In
 addition, equivalent
 replacement parts to correct
 the unsafe condition under
 PMA (other than identicality)
 may also be installed
 provided they meet current
 airworthiness standards,
 which include those actions
 cited in this AD.
(6) You must contact the type   As of June 2, 2006      Not applicable.
 certificate holder any time a   (the effective date
 modification or repair is       of this AD).
 done that affects the parts
 listed in paragraphs (e)(1),
 (e)(2), (e)(3), and (e)(4) of
 this AD to determine the
 effect, if any, the
 modification or repair may
 have on the life limits
 established in this AD.
------------------------------------------------------------------------



[[Page 20001]]

     Note 1: The FAA recommends that you return all replaced 
backrest tubes to Pilatus Aircraft Ltd., Structural Analysis Group 
ECE, Ch-6371 Stans, Switzerland. Include the following information: 
crew seat P/N and serial number, aircraft manufacturer serial 
number, aircraft flying hours, number of flights, and replacement 
date of the replaced backrest tubes.


    Note 2: Pilatus PC-12 Aircraft Maintenance Manual Revision 17/
Interactive Electronic Technical Publication (IETP) Revision 9, 
Chapter 4, section 04-00-00, references the crew seat bucket 
assembly replacements.

Alternative Methods of Compliance (AMOCs)

    (f) The Manager, Standards Office, Small Airplane Directorate, 
FAA, ATTN: Doug Rudolph, Aerospace Engineer, FAA, Small Airplane 
Directorate, 901 Locust, Room 301, Kansas City, Missouri 64106; 
telephone: (816) 329-4059; fax: (816) 329-4090, has the authority to 
approve AMOCs for this AD, if requested using the procedures found 
in 14 CFR 39.19.

Related Information

    (g) Swiss AD Number HB-2005-470, Effective Date: December 30, 
2005, also addresses the subject of this AD.

    Issued in Kansas City, Missouri, on April 12, 2006.
Kim Smith,
Manager, Small Airplane Directorate, Aircraft Certification Service.
[FR Doc. 06-3725 Filed 4-18-06; 8:45 am]
BILLING CODE 4910-13-P