Federal Aviation Administration (FAA), DOT.
Final rule; request for comments.
We are adopting a new airworthiness directive (AD) for the products listed above that would supersede existing ADs. 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:
Findings of corrosion, wear and cracks in the upper wing strut fittings on some PC–6 aircraft have been reported in the past.
It is possible that the spherical bearing of the wing strut fittings installed in the underwing can be loose in the fitting or cannot rotate because of corrosion. In this condition, the joint cannot function as designed and fatigue cracks may then develop. Undetected cracks, wear and/or corrosion in this area could lead to failure on the upper attachment fitting. This could result in the failure of the wing structure with subsequent loss of control of the aircraft.
This AD requires actions that are intended to address the unsafe condition described in the MCAI.
This AD becomes effective September 26, 2007.
On September 26, 2007, the Director of the Federal Register approved the incorporation by reference of certain publications listed in this AD.
We must receive comments on this AD by October 22, 2007.
You may send comments by any of the following methods:
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You may examine the AD docket on the Internet at
Doug Rudolph, Aerospace Engineer, 901 Locust, Room 301, Kansas City, Missouri 64106; telephone: (816) 329–4059; fax: (816) 329–4090.
On January 24, 2007, we issued AD 2007–03–08, Amendment 39–14919 (72 FR 4635; February 1, 2007), and on July 19, 2007, we issued AD 2007–15–09, Amendment 39–15138 (72 FR 41436; July 30, 2007). Those ADs required actions intended to address an unsafe condition on the products listed above.
Since we issued AD 2007–03–08 and AD 2007–15–09, Pilatus reported that the right hand (RH) wing strut fitting of aircraft serial number 903 was found with one lug shoulder completely broken. The aircraft had accumulated 297 hours time-in-service since the RH wing strut fitting had been replaced in May of 2007. Based on this report, the foreign airworthiness authority has issued a new MCAI.
The European Aviation Safety Agency (EASA), which is the Technical Agent for the Member States of the European Community, has issued AD No. 2007–0241–E, dated September 5, 2007 (referred to after this as “the MCAI”), to correct an unsafe condition for the specified products. The MCAI states:
Findings of corrosion, wear and cracks in the upper wing strut fittings on some PC–6 aircraft have been reported in the past.
It is possible that the spherical bearing of the wing strut fittings installed in the underwing can be loose in the fitting or cannot rotate because of corrosion. In this condition, the joint cannot function as designed and fatigue cracks may then develop. Undetected cracks, wear and/or corrosion in this area could lead to failure on the upper attachment fitting. This could result in the failure of the wing structure with subsequent loss of control of the aircraft.
To address this problem the superseded FOCA Airworthiness Directives (AD) TM–L Nr. 80.627–6, HB–2006–400 and EASA AD 2007–0114 were issued to mandate specific inspections and to obtain a fleet status. Since the issuance of AD 2007–0114, the data reporting proved that it was necessary to establish repetitive inspections.
Thus, in addition to an extended applicability, the present AD mandates repetitive inspections of the upper wing strut fitting for cracks, wear and/or corrosion and examination of the spherical bearing and replacement of cracked fittings.
You may obtain further information by examining the MCAI in the AD docket.
Pilatus Aircraft Ltd. has issued Service Bulletin No. 57–005, dated August 30, 2007. The actions described in this service information are intended to correct the unsafe condition identified in the MCAI.
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.
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 have also required different actions in this AD from those in the MCAI in order to follow FAA policies. Any such differences are described in a separate paragraph of the AD. These requirements take precedence over those copied from the MCAI.
An unsafe condition exists that requires the immediate 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 it is possible that fatigue cracks exist on the wing strut fittings installed on the wing that are not detected during the inspections published in the aircraft maintenance manual or required by any previous service bulletin. Undetected cracks in this area could lead to failure of the fitting and consequent loss of control. 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.
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
We will post all comments we receive, without change, to
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.
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.
Air transportation, Aircraft, Aviation safety, Incorporation by reference, Safety.
49 U.S.C. 106(g), 40113, 44701.
(a) This airworthiness directive (AD) becomes effective September 26, 2007.
(b) This AD supersedes the following ADs:
(1) AD 2007–03–08; Amendment 39–14919; and
(2) AD 2007–15–09; Amendment 39–15138.
(c) This AD applies to:
(1) 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 (these airplanes are also identified as Fairchild Republic Company PC–6 airplanes, Fairchild Industries PC–6 airplanes, Fairchild Heli Porter PC–6 airplanes, or Fairchild-Hiller Corporation PC–6 airplanes);
(2) Manufacturer serial numbers (MSN) 101 through 999 and MSN 2001 through 2092;
(3) Airplanes that are equipped with left wing strut fitting part number (P/N) 6102.0041.00, P/N 111.35.06.055, P/N 111.35.06.184, or P/N 111.35.06.185; or equipped with right wing strut fitting P/N 6102.0041.00, P/N 111.35.06.056, P/N 111.35.06.184, or P/N 111.35.06.186, or FAA-approved equivalent part numbers; and
(4) Airplanes that are certificated in any category.
(d) Air Transport Association of America (ATA) Code 57: Wings.
(e) The mandatory continuing airworthiness information (MCAI) states:
Findings of corrosion, wear and cracks in the upper wing strut fittings on some PC–6 aircraft have been reported in the past.
It is possible that the spherical bearing of the wing strut fittings installed in the underwing can be loose in the fitting or cannot rotate because of corrosion. In this condition, the joint cannot function as designed and fatigue cracks may then develop. Undetected cracks, wear and/or corrosion in this area could lead to failure on the upper attachment fitting. This could result in the failure of the wing structure with subsequent loss of control of the aircraft.
To address this problem the superseded FOCA Airworthiness Directives (AD) TM–L Nr. 80.627–6, HB–2006–400 and EASA AD 2007–0114 were issued to mandate specific inspections and to obtain a fleet status. Since the issuance of AD 2007–0114, the data reporting proved that it was necessary to establish repetitive inspections.
Thus, in addition to an extended applicability, the present AD mandates repetitive inspections of the upper wing strut fitting for cracks, wear and/or corrosion and examination of the spherical bearing and replacement of cracked fittings.
(f) Unless already done, do the following actions:
(1)
(2)
(3)
(4)
(5)
This AD differs from the MCAI and/or service information as follows: No differences.
(g) The following provisions also apply to this AD:
(1)
(2)
(3)
(h) Refer to MCAI European Aviation Safety Agency (EASA) AD No: 2007–0241–E, dated September 05, 2007; Pilatus Aircraft Ltd. Service Bulletin No. 57–005, dated August 30, 2007; and Pilatus Aircraft Ltd. Service Bulletin No. 57–004, dated April 16, 2007, for related information.
(i) You must use Pilatus Aircraft Ltd. Service Bulletin No. 57–005, dated August 30, 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.,
(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: