AD 2008-02-03

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:

It has been found that some of the above mentioned MLG special bolts can be defective. The problem is only applicable to specific bolts with serial numbers that start with the letters AT or have the supplier code AT. Investigations revealed that there is a possibility for hydrogen embrittlement which occurs during the manufacture process.

Components in this condition can decrease the specific fatigue life and could lead to MLG collapse during operation with consequent loss of airplane control.

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

Final rule.

2008-02-03 Pilatus Aircraft Limited: Amendment 39-15333; Docket No. FAA-2007-0116; Directorate Identifier 2007-CE-082-AD.

Effective Date

(a) This airworthiness directive (AD) becomes effective February 20, 2008.

Affected ADs

(b) None.

Applicability

(c) This AD applies to PC-12, PC-12/45, and PC-12/47 airplanes, serial numbers 101 through 749, certificated in any category; that have not incorporated the actions in their entirety of PILATUS AIRCRAFT LTD. PC-12 Service Bulletin No: 32-020, dated July 24, 2007; and with one or more of the following installed:

(1) Main landing gear (MLG) assemblies delivered before December 31, 2006, with the following part numbers (P/N): 532.10.12.037, 532.10.12.038, 532.10.12.041, 532.10.12.042, 532.10.12.043, 532.10.12.044, 532.10.12.047, 532.10.12.048, 532.10.12.049, 532.10.12.050, 532.10.12.051, or 532.10.12.052;

(2) Special bolts P/N 532.10.12.110, 532.10.12.205, 532.10.12.077, or 532.10.12.202 delivered before December 31, 2006; or

(3) Modification kit numbers 500.50.12.267, 500.50.12.286, or 500.50.12.299 delivered before December 31, 2006.

Subject

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

Reason

(e) The mandatory continuing airworthiness information (MCAI) states:

It has been found that some of the above mentioned MLG special bolts can be defective. The problem is only applicable to specific bolts with serial numbers that start with the letters AT or have the supplier code AT. Investigations revealed that there is a possibility for hydrogen embrittlement which occurs during the manufacture process.

Components in this condition can decrease the specific fatigue life and could lead to MLG collapse during operation with consequent loss of airplane control.
In order to correct the situation, this AD requires the identification of all MLG special bolts to determine if the bolts have serial numbers that start with the letters AT or have the supplier code AT and the replacement of affected special bolts.

Actions and Compliance

(f) Unless already done, do the following actions:

(1) Within the next 100 hours time-in-service (TIS) after February 20, 2008 (the effective date of this AD) or within the next 3 months after February 20, 2008 (the effective date of this AD), whichever occurs first, inspect the special bolts that attach the MLG retraction actuators and the special bolts that attach the shock absorbers to the MLG assemblies to identify the serial numbers that start with the letters AT or have the supplier code AT following PILATUS AIRCRAFT LTD. PC-12 Service Bulletin No: 32-020, Rev. No. 1, dated November 22, 2007.

(2) If during the inspection required in paragraph (f)(1) of this AD any special bolts with the serial number starting with the letters AT or special bolts with the supplier code AT are found, before further flight, replace the specified bolts with new bolts with the new part numbers in all MLG assemblies following PILATUS AIRCRAFT LTD. PC-12 Service Bulletin No: 32-020, Rev. No. 1, dated November 22, 2007.

(3) As of February 20, 2008 (the effective date of this AD), do not install any of the special bolts that have serial numbers that start with the letters AT or have the supplier code AT on Models PC- 12, PC-12/45, and PC-12/47 airplanes as indicated in PILATUS AIRCRAFT LTD. PC-12 Service Bulletin No: 32-020, Rev. No. 1, dated November 22, 2007. MLG assemblies, special bolts, and modifications kits, as referenced in paragraphs (c)(1), (c)(2), and (c)(3) of this AD, delivered from PILATUS AIRCRAFT LTD. on or after December 31, 2006, will not incorporate the unsafe condition.

FAA AD Differences

Note: 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. 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 thePaperwork 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 Federal Office of Civil Aviation (FOCA) AD HB-2007- 382, dated August 27, 2007; and PILATUS AIRCRAFT LTD. PC-12 Service Bulletin No: 32-020, Rev. No. 1, dated November 22, 2007, for related information.

Material Incorporated by Reference

(i) You must use PILATUS AIRCRAFT LTD. PC-12 Service Bulletin No: 32-020, Rev. No. 1, dated November 22, 2007, 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 Support Manager, CH-6371 STANS, Switzerland; telephone: +41 41 619 6208; fax: +4141 619 7311; e- mail: SupportPC12@pilatus-aircraft.com.

(3) You may review copies at the FAA, Central Region, Office of the Regional Counsel, 901 Locust, Room 506, Kansas City, Missouri 64106; or 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/cfr/ibr-locations.html .

Discussion

We issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 to include an AD that would apply to the specified products. That NPRM was published in the Federal Register on October 31, 2007 (72 FR 61580). That NPRM proposed to correct an unsafe condition for the specified products. The MCAI states:

It has been found that some of the above mentioned MLG special bolts can be defective. The problem is only applicable to specific bolts with serial numbers that start with the letters AT or have the supplier code AT. Investigations revealed that there is a possibility for hydrogen embrittlement which occurs during the manufacture process.

Components in this condition can decrease the specific fatigue life and could lead to MLG collapse during operation with consequent loss of airplane control.

In order to correct the situation, this AD requires the identification of all MLG special bolts to determine if the bolts haveserial numbers that start with the letters AT or have the supplier code AT and the replacement of affected special bolts.

Comments

We gave the public the opportunity to participate in developing this AD. We considered the comment received.

Comment Issue: Revision of Service Bulletin No. 32-020

PILATUS AIRCRAFT LTD. comments they have revised the applicable service information, and the latest version is PILATUS AIRCRAFT LTD. Service Bulletin No. 32-020, Rev. No. 1, dated November 22, 2007. They request we incorporate the revised version of the service bulletin into our AD.

We agree that we should incorporate the revised version of the service bulletin into our AD. We have discussed the revised service bulletin with the Federal Office of Civil Aviation (FOCA), which is the aviation authority for Switzerland, and they also agree we should incorporate the revised version of the service bulletin into our AD.

We will change the final rule AD action to incorporatePILATUS AIRCRAFT LTD. Service Bulletin No. 32-020, Rev. No. 1, dated November 22, 2007.

Conclusion

We reviewed the available data, including the comment received, and determined that air safety and the public interest require adopting the AD

[[Page 2802]]

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 followFAA policies. Any such differences are highlighted in a NOTE within the AD.

Costs of Compliance

We estimate that this AD will affect 480 products of U.S. registry. We also estimate that it will take about .5 work-hour per product to comply with basic requirements of this AD. The average labor rate is $80 per work-hour.

Based on these figures, we estimate the cost of this AD to the U.S. operators to be $19,200, or $40 per product.

In addition, we estimate that any necessary follow-on actions would take about 4 work-hours and require parts costing $2,300, for a cost of $2,620 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.

Adoption of the Amendment

Accordingly, under the authority delegated to me by the Administrator, the FAA amends 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. The FAA amends Sec. 39.13 by adding the following new AD: