Airworthiness Directives; PILATUS AIRCRAFT LTD. Models PC-12, PC-12/45, PC-12/47 and PC-12/47E Airplanes

AGENCY:

Federal Aviation Administration (FAA), Department of Transportation (DOT).

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

We propose to adopt a new airworthiness directive (AD) for the products listed above that would supersede an existing AD. This proposed AD results from mandatory continuing airworthiness information (MCAI) originated by an aviation authority of another country to identify and correct an unsafe condition on an aviation product. The MCAI (two different MCAI) describe the unsafe conditions as:

FOCA AD HB 2002-271 was issued because the Nose Landing Gear (NLG) Right Hand (RH) upper drag link, Part Number (P/N) 532.20.12.140 was found broken on some aircraft due to fatigue cracking, and therefore a life limit of 4,000 landings was introduced.

Recent investigation of a new occurrence revealed that the replacement part NLG RH upper drag link P/N 532.20.12.289 also suffered fatigue cracking, however on a different location.

Complete failure of the NLG RH upper drag link could result in NLG collapse during landing.

and

This Airworthiness Directive (AD) is prompted by reports of several in-service cracked torque tubes. A reduced wall thickness produced during the manufacturing process has been determined to be the initial cause. Additionally, all the involved torque tubes have been found to show fatigue cracking problems.

Such a condition, if left uncorrected, could lead to failure of the torque tube and result in loss of the steering control on ground and consequent unsafe condition.

The proposed AD would require actions that are intended to address the unsafe conditions described in the MCAI.

DATES:

We must receive comments on this proposed AD by June 8, 2009.

ADDRESSES:

You may send comments by any of the following methods:

• Federal eRulemaking Portal: Go to http://www.regulations.gov. Follow the instructions for submitting comments.
• Fax: (202) 493-2251.
• Mail: U.S. Department of Transportation, Docket Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue, SE., Washington, DC 20590.
• Hand Delivery: U.S. Department of Transportation, Docket Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue, SE., Washington, DC 20590, between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays.

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 this proposed AD, 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.

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:

Comments Invited

We invite you to send any written relevant data, views, or arguments about this proposed AD. Send your comments to an address listed under the ADDRESSES section. Include “Docket No. FAA-2009-0437; Directorate Identifier 2009-CE-018-AD” at the beginning of your comments. We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects of this proposed AD. We will consider all comments received by the closing date and may amend this proposed AD because of those comments.

We will post all comments we receive, without change, to http://regulations.gov,, including any personal information you provide. We will also post a report summarizing each substantive verbal contact we receive about this proposed AD.

Discussion

On July 7, 2003, we issued AD 2003-14-07, Amendment 39-13226 (68 FR 41903; July 16, 2003). That AD required actions intended to address an unsafe condition on the products listed above.

Since we issued AD 2003-14-07, an investigation of a new occurrence of an upper drag link failure revealed that the replacement part NLG RH upper drag link P/N 532.20.12.289 also suffered fatigue cracking, however at a different location.

The European Aviation Safety Agency (EASA), which is the Technical Agent for the Member States of the European Community, has issued AD No.: 2009-0086 dated April 14, 2009, and AD No.: 2009-0060 dated March 11, 2009 (referred to after this as “the MCAI”), to correct the unsafe conditions for the specified products. The MCAI (two different MCAI) states:

FOCA AD HB 2002-271 was issued because the Nose Landing Gear (NLG) Right Hand (RH) upper drag link, Part Number (P/N) 532.20.12.140 was found broken on some aircraft due to fatigue cracking, and therefore a life limit of 4,000 landings was introduced.

Recent investigation of a new occurrence revealed that the replacement part NLG RH upper drag link P/N 532.20.12.289 also suffered fatigue cracking, however on a different location.

Complete failure of the NLG RH upper drag link could result in NLG collapse during landing. To address that condition, this AD is issued to mandate the implementation of the latest revision of the PC-12 Aircraft Maintenance Manual (AMM) chapter 4—airworthiness limitations section—by establishing repetitive inspections for the NLG RH upper drag links P/N 532.20.12.140 and P/N 532.20.12.289.

and

This Airworthiness Directive (AD) is prompted by reports of several in-service cracked torque tubes. A reduced wall thickness produced during the manufacturing process has been determined to be the initial cause. Additionally, all the involved torque tubes have been found to show fatigue cracking problems.

Such a condition, if left uncorrected, could lead to failure of the torque tube and result in loss of the steering control on ground and consequent unsafe condition.

For the reason described above, this new AD mandates the replacement of certain torque tubes by new ones of an improved design and the latest revision of chapter 4 `limitations' of the PC-12 Aircraft Maintenance Manual (AMM) which introduces the new life limit for torque tubes with Part Number (P/N) 532.50.12.047.

You may obtain further information by examining the MCAI in the AD docket.

Relevant Service Information

PILATUS AIRCRAFT LTD. has issued Service Bulletin No: 32-021, dated November 21, 2008. The actions described in this service information are intended to correct the unsafe condition identified in the MCAI.

FAA's Determination and Requirements of the Proposed AD

This product has been approved by the aviation authority of another country, and is approved for operation in the United States. Pursuant to our bilateral agreement with this State of Design Authority, they have notified us of the unsafe condition described in the MCAI and service information referenced above. We are proposing this AD because we evaluated all information and determined the unsafe condition exists and is likely to exist or develop on other products of the same type design.

Differences Between This Proposed 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 proposed 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 proposed AD.

Costs of Compliance

Based on the service information, we estimate that this proposed AD will affect 540 products of U.S. registry. We also estimate that it would take about 3.5 work-hours per product to comply with the basic requirements of this proposed AD. The average labor rate is $80 per work-hour. Required parts would cost about $300 per product.

Based on these figures, we estimate the cost of the proposed AD on U.S. operators to be $313,200, or $580 per product.

In addition, we estimate that any necessary follow-on actions would take about 6 work-hours and require parts costing $4,000, for a cost of $4,480 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 proposed AD would not have federalism implications under Executive Order 13132. This proposed AD 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.

For the reasons discussed above, I certify this proposed regulation:

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 regulatory evaluation of the estimated costs to comply with this proposed AD and placed it in the AD docket.

List of Subjects in 14 CFR Part 39

• Air transportation
• Aircraft
• Aviation safety
• Incorporation by reference
• Safety

The Proposed Amendment

Accordingly, under the authority delegated to me by the Administrator, the FAA proposes to amend 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.