Airworthiness Directive · Amendment 39-14919 · Pilatus Aircraft Ltd., PC-6 Series Airplanes
Pilatus Aircraft Ltd., PC-6 Series Airplanes
Superseded. A later AD replaced this one: AD 2007-19-14. Comply with the one in force.
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) 101 through 949, MSN 951, and MSN 2001 through 2092; that are certificated in any category. 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.
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 the discovery of exfoliation corrosion in the fittings of some PC-6 airplanes. These fittings are installed exterior to the bottom skin of the wing skin. If not corrected, undetected corrosion in this area could lead to failure of the fitting and subsequent loss of control of the airplane. We are issuing this AD to require actions to correct the unsafe condition on these products.
Unless already done, do the following actions.
(1) Within 12 months after the effective date of this AD and repetitively thereafter at intervals not to exceed 12 months, perform an inspection required by paragraph 3.B.(2) of PILATUS PC-6 Service Bulletin (SB) No. 57-003, dated June 13, 2006, of the fittings Part Number (P/N) 6102.0041.00, P/N 111.35.06.055 or P/N 111.35.06.056 for signs of corrosion. Repair of minor surface corrosion is permitted according to the Repair and Overhaul Manual (ROM) (Report No. 1391), Chap. 2 and 4. Corrosion outside these limits is not permitted.
(2) If during any of the inspections required by paragraph (e)(1) of this AD, any minor surface corrosion is found, prior to further flight, remove the minor surface corrosion (Ref. ROM. Chap. 2 and 4).
(3) If during any of the inspections required by paragraph (e)(1) of this AD, any corrosion out of limits is found (Ref. ROM, Chap. 2 and 4), prior to further flight, replace the fittings in accordance with paragraph 4 of PILATUS PC-6 SB No. 57-003, dated June 13, 2006, with new (retrofit) fittings P/N 111.35.06.185 and/or P/N 111.35.06.186.
(4) Replacement of the fittings with new (improved) fittings P/N 111.35.06.185 (left hand side) and/or 111.35.06.186 (right hand side) terminates the repetitive inspection for that side.
Note: This AD differs from the MCAI and/or service information as follows: (1) The FAA AD is requiring repetitive inspections, not just a one-time inspection as required in the MCAI. (2) The Service Bulletin specifies “subsequent inspections for corrosion will be included in Chapter 5 of the Aircraft Maintenance Manual (AMM).” The only way we (FAA) can mandate these repetitive inspections is through an AD.
The aircraft, engines and makers this AD names, by the model designations in its text. A model listed here may still be outside the AD's serial ranges.
