
[Federal Register: December 28, 2009 (Volume 74, Number 247)]
[Rules and Regulations]               
[Page 68499-68501]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr28de09-7]                         

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2009-0938 Directorate Identifier 2009-CE-052-AD; 
Amendment 39-16140; AD 2009-26-05]
RIN 2120-AA64

 
Airworthiness Directives; PILATUS Aircraft Ltd. Model PC-7 
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 the 
products listed above. This AD results from mandatory continuing 
airworthiness information (MCAI) issued 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:

    This Airworthiness Directive (AD) is prompted due to the 
discovery of cracks caused by stress corrosion in the main-gear 
support struts. All the main-gear support struts that had cracks 
were made from material AA2024-T351 which has a lower resistance to 
stress corrosion cracking.
    Such cracks, if undetected, could lead to the failure of the 
strut during landing which could then cause the Main Landing Gear 
(MLG) to collapse.

We are issuing this AD to require actions to correct the unsafe 
condition on these products.

DATES: This AD becomes effective February 1, 2010.
    On February 1, 2010, the Director of the Federal Register approved 
the incorporation by reference of certain publications listed in this 
AD.

ADDRESSES: You may examine the AD docket on the Internet at http://
www.regulations.gov or in person at Document Management Facility, U.S. 
Department of Transportation, Docket Operations, M-30, West Building 
Ground Floor, Room W12-140, 1200 New Jersey Avenue, SE., Washington, DC 
20590.

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; e-mail: 
doug.rudolph@faa.gov.

SUPPLEMENTARY INFORMATION:

Discussion

    We issued a notice of proposed rulemaking (NPRM) to amend 14 CFR

[[Page 68500]]

part 39 to include an AD that would apply to the specified products. 
That NPRM was published in the Federal Register on October 9, 2009 (74 
FR 52156). That NPRM proposed to correct an unsafe condition for the 
specified products. The MCAI states:

    This Airworthiness Directive (AD) is prompted due to the 
discovery of cracks caused by stress corrosion in the main-gear 
support struts. All the main-gear support struts that had cracks 
were made from material AA2024-T351 which has a lower resistance to 
stress corrosion cracking.
    Such cracks, if undetected, could lead to the failure of the 
strut during landing which could then cause the Main Landing Gear 
(MLG) to collapse.
    In order to correct and control the situation, this AD mandates 
the identification of the main-gear support struts to check if they 
have rounded clevis lugs and a Non-Destructive Inspection (NDI) 
procedure on the main-gear support struts if they have chamfered 
clevis lugs.

For main-gear support struts with chamfered clevis lugs that show 
cracks during the NDI, the MCAI also requires replacing any cracked 
main-gear support struts with parts of improved design. You may obtain 
further information by examining the MCAI in the AD docket.

Comments

    We gave the public the opportunity to participate in developing 
this AD. We considered the comment received.
    PILATUS Aircraft Ltd. states that there is a typographical error in 
one of the affected part numbers (P/N) referenced in the proposed AD. 
The P/N should read 114.48.07.127 instead of 114.48.07.172.
    We agree with the commenter and will make that change in final rule 
AD action.

Conclusion

    We reviewed the available data, including the comment received, and 
determined that air safety and the public interest require adopting the 
AD with the changes described previously. We determined that these 
changes will not increase the economic burden on any operator or 
increase the scope of the AD.

Differences Between This AD and the MCAI or Service Information

    We have reviewed the MCAI and related service information and, in 
general, agree with their substance. But we might have found it 
necessary to use different words from those in the MCAI to ensure the 
AD is clear for U.S. operators and is enforceable. In making these 
changes, we do not intend to differ substantively from the information 
provided in the MCAI and related service information.
    We might also have required different actions in this AD from those 
in the MCAI in order to follow FAA policies. Any such differences are 
highlighted in a NOTE within the AD.

Costs of Compliance

    We estimate that this AD will affect 10 products of U.S. registry. 
We also estimate that it will take about 4 work-hours per product to 
comply with the basic requirements of this AD. The average labor rate 
is $80 per work-hour.
    Based on these figures, we estimate the cost of the AD on U.S. 
operators to be $3,200, or $320 per product.
    In addition, we estimate that any necessary follow-on actions will 
take about 20 work-hours and require parts costing $20,000, for a cost 
of $21,600 per product. We have no way of determining the number of 
products that may need these actions.

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 
rulemaking action.

Regulatory Findings

    We 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 this AD:
    (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.
    We prepared a regulatory evaluation of the estimated costs to 
comply with this AD and placed it in the AD Docket.

Examining the AD Docket

    You may examine the AD docket on the Internet at http://
www.regulations.gov; or in person at the Docket Management Facility 
between 9 a.m. and 5 p.m., Monday through Friday, except Federal 
holidays. The AD docket contains the NPRM, the regulatory evaluation, 
any comments received, and other information. The street address for 
the Docket Office (telephone (800) 647-5527) is in the ADDRESSES 
section. Comments will be available in the AD docket shortly after 
receipt.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Incorporation by 
reference, Safety.

Adoption of the Amendment

0
Accordingly, under the authority delegated to me by the Administrator, 
the FAA amends 14 CFR part 39 as follows:

PART 39--AIRWORTHINESS DIRECTIVES

0
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]

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

2009-26-05 Pilatus Aircraft Ltd: Amendment 39-16140; Docket No. FAA-
2009-0938; Directorate Identifier 2009-CE-052-AD.

Effective Date

    (a) This airworthiness directive (AD) becomes effective February 
1, 2010.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to Model PC-7 airplanes, manufacturer serial 
numbers 101 through 618 that are:
    (1) Equipped with main-gear support struts part number (P/N) 
532.10.09.039 or P/N 114.48.07.127; and
    (2) Certificated in any category.

Subject

    (d) Air Transport Association of America (ATA) Code 32: Landing 
Gear.

[[Page 68501]]

Reason

    (e) The mandatory continuing airworthiness information (MCAI) 
states:
    This Airworthiness Directive (AD) is prompted due to the 
discovery of cracks caused by stress corrosion in the main-gear 
support struts. All the main-gear support struts that had cracks 
were made from material AA2024-T351 which has a lower resistance to 
stress corrosion cracking.
    Such cracks, if undetected, could lead to the failure of the 
strut during landing which could then cause the Main Landing Gear 
(MLG) to collapse.
    In order to correct and control the situation, this AD mandates 
the identification of the main-gear support struts to check if they 
have rounded clevis lugs and a Non-Destructive Inspection (NDI) 
procedure on the main-gear support struts if they have chamfered 
clevis lugs.

For main-gear support struts with chamfered clevis lugs that show 
cracks during the NDI, the MCAI also requires replacing any cracked 
main-gear support struts with parts of improved design. You may 
obtain further information by examining the MCAI in the AD docket.

Actions and Compliance

    (f) Unless already done, do the following actions:
    (1) Within the next 30 hours time-in-service (TIS) after 
February 1, 2010 (the effective date of this AD) or within the next 
30 days after February 1, 2010 (the effective date of this AD), 
whichever occurs first, visually inspect the left and right main-
gear support struts to determine if they have rounded or chamfered 
clevis lugs. Do the inspection following paragraph 3.A. of Pilatus 
PC-7 Service Bulletin No. 32-024, Rev. No. 1, dated November 17, 
2008.
    (2) Based on the results of the inspection required in paragraph 
(f)(1) of this AD, if the main-gear support strut has rounded clevis 
lugs, no further action is required except the requirement specified 
in paragraph (f)(4) of this AD still applies. Make an entry in the 
airplane logbook to show compliance with this AD. Based on the 
reports of the results of the inspection required by this AD, 
further rulemaking action may be taken to mandate repetitive 
inspections or terminating action.
    (3) Based on the results of the inspection required in paragraph 
(f)(1) of this AD, if the main-gear support strut has chamfered 
clevis lugs, before further flight do a Non-Destructive Inspection 
(NDI). Do the NDI following paragraphs 3.B. through 3.E. of Pilatus 
PC-7 Service Bulletin No. 32-024, Rev. No. 1, dated November 17, 
2008.
    (i) If cracks are found during the inspection required in 
paragraph (f)(3) of this AD:
    (A) Before further flight after the inspection, replace any 
cracked main-gear support struts with new main-gear support struts, 
P/N 532.10.09.128. Do the replacement following Pilatus PC-7 Service 
Bulletin No. 32-025, Rev. No. 1, dated November 17, 2008.
    (B) Within the next 10 days after the inspection, report the 
cracks to Pilatus Aircraft LTD., Customer Liaison Manager, CH-6371 
STANS, Switzerland, using the Crack Report Form (Figure 4) in 
Pilatus PC-7 Service Bulletin No. 32-024, Rev. No. 1, dated November 
17, 2008.
    (ii) If no cracks are found during the inspection required in 
paragraph (f)(3) of this AD, no further action is required. Make an 
entry in the airplane logbook to show compliance with this AD.
    (4) As of 30 days after February 1, 2010 (the effective date of 
this AD), do not install any main-gear support struts, P/N 
532.10.09.039 or P/N 114.48.07.127, with chamfered clevis lugs.

    Note 1:  If you have any main-gear support struts, P/N 
532.10.09.039 or P/N 114.48.07.127, with chamfered clevis lugs held 
as spares, you may return them to Pilatus Aircraft Ltd., Customer 
Liaison Manager, CH-6371 STANS, Switzerland, for replacement with a 
new main-gear support strut, P/N 532.10.09.128.

FAA AD Differences

    Note 2:  This AD differs from the MCAI and/or service 
information as follows: No differences.

Other FAA AD Provisions

    (g) The following provisions also apply to this AD:
    (1) Alternative Methods of Compliance (AMOCs): The Manager, 
Standards Office, FAA, has the authority to approve AMOCs for this 
AD, if requested using the procedures found in 14 CFR 39.19. Send 
information to 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; e-mail: 
doug.rudolph@faa.gov. Before using any approved AMOC on any airplane 
to which the AMOC applies, notify your appropriate principal 
inspector (PI) in the FAA Flight Standards District Office (FSDO), 
or lacking a PI, your local FSDO.
    (2) Airworthy Product: For any requirement in this AD to obtain 
corrective actions from a manufacturer or other source, use these 
actions if they are FAA-approved. Corrective actions are considered 
FAA-approved if they are approved by the State of Design Authority 
(or their delegated agent). You are required to assure the product 
is airworthy before it is returned to service.
    (3) Reporting Requirements: For any reporting requirement in 
this AD, under the provisions of the Paperwork Reduction Act (44 
U.S.C. 3501 et seq.), the Office of Management and Budget (OMB) has 
approved the information collection requirements and has assigned 
OMB Control Number 2120-0056.

Related Information

    (h) Refer to MCAI Federal Office of Civil Aviation AD HB-2009-
011, dated September 10, 2009; and Pilatus PC-7 Service Bulletin No. 
32-024, Rev. No. 1, dated November 17, 2008; and Pilatus PC-7 
Service Bulletin No. 32-025, Rev. No. 1, dated November 17, 2008, 
for related information.

Material Incorporated by Reference

    (i) You must use Pilatus PC-7 Service Bulletin No. 32-024, Rev. 
No. 1, dated November 17, 2008; and Pilatus PC-7 Service Bulletin 
No. 32-025, Rev. No. 1, dated November 17, 2008, to do the actions 
required by this AD, unless the AD specifies otherwise.
    (1) The Director of the Federal Register approved the 
incorporation by reference of this service information under 5 
U.S.C. 552(a) and 1 CFR part 51.
    (2) For service information identified in this AD, contact 
Pilatus Aircraft LTD., Customer Service Manager, CH-6371 STANS, 
Switzerland; telephone: +41 (0)41 619 62 08; fax: +41 (0)41 619 73 
11; Internet: http://www.pilatus-aircraft.com/, or e-mail: 
snolan@pilatus-aircraft.com.
    (3) You may review copies of the service information 
incorporated by reference for this AD at the FAA, Central Region, 
Office of the Regional Counsel, 901 Locust, Kansas City, Missouri 
64106. For information on the availability of this material at the 
Central Region, call (816) 329-3768.
    (4) You may also review copies of the service information 
incorporated by reference for this AD at the National Archives and 
Records Administration (NARA). For information on the availability 
of this material at NARA, call (202) 741-6030, or go to: http://
www.archives.gov/federal_register/code_of_federal_regulations/
ibr_locations.html.

    Issued in Kansas City, MO, on December 8, 2009.
Margaret Kline,
Acting Manager, Small Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. E9-29983 Filed 12-24-09; 8:45 am]

BILLING CODE 4910-13-P
