AD 2008-16-03

We are adopting a new airworthiness directive (AD) for the products listed above. This AD results from mandatory continuing airworthiness information (MCAI) issued by the 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 cracked or broken leaf springs P/N 6232.0175.01 installed in the overhead flap-operating mechanism of some PC-6 aircraft. A broken leaf spring could lead to an uncommanded flap retraction which could lead to hazardous situations and subsequent loss of control of the aircraft.

This AD requires actions that are intended to address the unsafe condition described in the MCAI.

Final rule; request for comments.

2008-16-03 Pilatus Aircraft Limited: Amendment 39-15621; Docket No. FAA-2008-0822; Directorate Identifier 2008-CE-045-AD.

Effective Date

(a) This airworthiness directive (AD) becomes effective August 11, 2008.

Affected ADs

(b) None.

Applicability

(c) This AD applies to Models PC-6, PC-6-H1, PC-6-H2, PC-6/350, PC-6/350-H1, PC-6/350-H2, PC-6/A, PC-6/A-H1, PC-6/A-H2, PC-6/B-H2, PC-6/B1-H2, PC-6/B2-H2, PC-6/B2-H4, PC-6/C-H2, and PC-6/C1-H2 airplanes, manufacturer serial numbers (MSN) MSN 101 through MSN 999 and MSN 2001 through MSN 2092, certificated in any category, with mechanically operated flaps and leaf springs, part number (P/N) 6232.0175.01 installed in the overhead flap-operating mechanism.

Note: These airplanes may also be identified as Fairchild Republic Company PC-6 airplanes, Fairchild Heli Porter PC-6 airplanes, or Fairchild-Hiller Corporation PC-6 airplanes.

Subject

(d) Air Transport Association of America (ATA) Code 27: Flight Controls.

Reason

(e) The mandatory continuing airworthiness information (MCAI) states:
This Airworthiness Directive (AD) is prompted due to the discovery of cracked or broken leaf springs P/N 6232.0175.01 installed in the overhead flap-operating mechanism of some PC-6 aircraft. A broken leaf spring could lead to an uncommanded flap retraction which could lead to hazardous situations and subsequent loss of control of the aircraft.
This AD is published by Federal Office of Civil Aviation (FOCA) Switzerland, as State of production and because it is possible that the leaf springs were not manufactured properly.
In order to correct and control the situation, this AD requires the initial and repetitive inspections of the leaf springs in the flap operating mechanism and the replacement of broken parts.

Actions and Compliance

(f) Unless already done, do the following actions:
(1) Before the next flight after the effective date of this AD, do a visual inspection of theleaf springs installed in the overhead flap-operating mechanism for cracks following Pilatus Aircraft Ltd. Pilatus PC-6 Service Bulletin No. 27-002, dated July 2, 2008.
(2) If any cracks are found in the leaf springs installed in the overhead flap-operating mechanism, before further flight, remove the three leaf springs, P/N 6232.0175.01, installed in the overhead flap-operating mechanism, and replace with three new leaf springs, P/N 116.45.06.040, in the overhead flap-operating mechanism following Pilatus Aircraft Ltd. Pilatus PC-6 Service Bulletin No. 27-003, dated July 2, 2008.
(3) Repetitively inspect thereafter at intervals not to exceed 25 hours time-in-service following Pilatus Aircraft Ltd. Pilatus PC- 6 Service Bulletin No. 27-002, dated July 2, 2008, until the modification required in paragraph (f)(2) of this AD is done. If any cracks are found in the leaf springs installed in the overhead flap- operating mechanism, before further flight, remove the three leaf springs,P/N 6232.0175.01, and replace with three new leaf springs, P/N 116.45.06.040, following Pilatus Aircraft Ltd. Pilatus PC-6 Service Bulletin No. 27-003, dated July 2, 2008.
(4) As of the effective date of this AD, do not install any P/N 6232.0175.01 leaf spring in the overhead flap-operating mechanism.

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) AirworthyProduct: 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.

Special Flight Permit

(h) If cracks are detected during the inspection required in (f)(1) or (f)(3) of this AD, no further flight is permitted until the modification required in paragraph (f)(2) or (f)(3) of this AD is done.

Related Information

(i) Refer to MCAI FOCA EMERGENCY AD HB-2008-242, dated July 4, 2008, and Pilatus Aircraft Ltd. Pilatus PC-6 Service Bulletin No. 27-002 and Pilatus Aircraft Ltd. Pilatus PC-6 Service Bulletin 27- 003, both dated July 2, 2008, for related information.

Material Incorporated by Reference

(j) You must use Pilatus Aircraft Ltd. Pilatus PC-6 Service Bulletin No. 27-002 and Pilatus Aircraft Ltd. Pilatus PC-6 Service Bulletin 27-003, both dated July 2, 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 Liaison Manager, CH 6371 STANS, Switzerland; telephone: + 41 (0)41 619 6580; fax: + 41 (0)41 619 6576; e-mail: fodermatt@pilatus aircaft.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

The Federal Office of Civil Aviation (FOCA), which is the aviation authority for Switzerland, has issued FOCA EMERGENCY AD HB-2008-242
(referred to after this as "the MCAI''), to correct an unsafe condition for the specified products. The MCAI states:

This Airworthiness Directive (AD) is prompted due to the discovery of cracked or broken leaf springs P/N 6232.0175.01 installed in the overhead flap-operating mechanism of some PC-6 aircraft. A broken leaf spring could lead to an uncommanded flap retraction which could lead to hazardous situations and subsequent loss of control of the aircraft.
This AD is published by Federal Office of Civil Aviation (FOCA) Switzerland, as State of production and because it is possible that the leaf springs were not manufactured properly.
In order to correct and control the situation, this AD requires the initial and repetitive inspections of the leaf springs in the flap operating mechanism and the replacement of broken parts.

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

Relevant Service Information

Pilatus Aircraft Limited has issued Pilatus PC-6 Service Bulletin No. 27-002 and Pilatus PC-6 Service Bulletin 27-003, both dated July 2, 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 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 issuing this AD because we evaluated all information provided by the State of Design Authority and determined the unsafe condition exists and is likely to exist or develop on other products of the same type design.

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.
The MCAI allows for replacement parts with like parts that are prone to cracking. The reason for the 25-hour repetitive inspection is because the cracks are occurring quickly. We believe that allowing replacement with the same part numbers that are cracking when improved design part numbers exist allows the unsafe condition to continue. Therefore we are requiring replacement with the new improved part numbers if cracks are found.

FAA's Determination of the Effective Date

An unsafe condition exists that requires theimmediate adoption of this AD. The FAA has found that the risk to the flying public justifies waiving notice and comment prior to adoption of this rule because a broken leaf spring could lead to an uncommanded flap retraction and lead to loss of control during final approach. Therefore, we determined that notice and opportunity for public comment before issuing this AD are impracticable and that good cause exists for making this amendment effective in fewer than 30 days.

Comments Invited

This AD is a final rule that involves requirements affecting flight safety, and we did not precede it by notice and opportunity for public comment. We invite you to send any written relevant data, views, or arguments about this AD. Send your comments to an address listed under the ADDRESSES section. Include "Docket No. FAA-2008-0822; Directorate Identifier 2008-CE-045-AD'' at the beginning of your comments. We specifically invite comments on the overall regulatory, economic, environmental, andenergy aspects of this AD. We will consider all comments received by the closing date and may amend this AD because of those comments.
We will post all comments we receive, without change, to http:// www.regulations.gov, including any personal information you provide. We will also post a report summarizing each substantive verbal contact we receive about this AD.

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 theAdministrator 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 that 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.

List of Subjects in 14 CFR Part 39

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

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: