AD 2021-02-04 Airworthiness Directives; Pilatus Aircraft Ltd. Airplanes

Makes named: pilatus. Models named: PC-12/47E. Read the applicability below — it usually turns on serial or part numbers too.

This AD applies to Pilatus Aircraft Ltd. Model PC-12/47E airplanes, all serial numbers (S/Ns), certificated in any category.

(1) For airplanes with a S/N 1576 and higher, unless already done, within 100 hours time-in-service (TIS) after the effective date of this AD or within 6 months after the effective date of this AD, whichever occurs first, inspect the left-hand (LH) and right-hand (RH) IFFAs for correct shape and clearance with the LH and RH tension rods by following step 3.B.(1) and Figures 2 and 3 of the Accomplishment Instructions—Aircraft in Pilatus PC-12 Service Bulletin No: 27-026, dated July 10, 2019 (Pilatus SB 27-026). (i) If the shape of the LH or RH IFFA is incorrect or if the clearance between the IFFA and the tension rod is less than 5 mm (0.2 inch), before further flight, modify the IFFA and inspect the tension rods for chafing by following section 3.C. of the Accomplishment Instructions—Aircraft in Pilatus SB 27-026. (ii) If the shape of the LH and RH IFFAs is correct and the clearance between the IFFA and the tension rod is at least 5 mm (0.2 inch), before further flight, inspect the front inboard LH and RH tension rods for chafing by following step 3.C.(12)(a) of the Accomplishment Instructions—Aircraft in Pilatus SB 27-026. If the LH or RH tension rod has any chafing, before further flight, replace the tension rod by following step 3.C.(12)(b) of the Accomplishment Instructions—Aircraft in Pilatus SB 27-026. (2) For airplanes with a S/N 1001 through S/N 1575, inclusive, that have a tension rod part number (P/N) 527.52.12.135 installed, unless already done, within 100 hours TIS after the effective date of this AD or within 6 months after the effective date of this AD, whichever occurs first, inspect the front inboard LH and RH tension rods for chafing by following step 3.C.(12)(a) of the Accomplishment Instructions—Aircraft in Pilatus SB 27-026. If the LH or RH tension rod has any chafing, before further flight, replace the tension rod by following step 3.C.(12)(b) of the Accomplishment Instructions—Aircraft in Pilatus SB 27-026. (3) For all Model PC-12/47E airplanes, as of the effective date of this AD, do not install on any airplane an LH IFFA P/N 557.52.12.223, RH IFFA P/N 557.52.12.224, or tension rod P/N 527.52.12.135 unless the part has been inspected and all corrective actions have been taken as required by this AD. (g) Alternative Methods of Compliance (AMOCs) The Manager, International Validation Branch, FAA, has the authority to approve AMOCs for this AD if requested using the procedures found in 14 CFR 39.19. Send information to Doug Rudolph, Aviation Safety Engineer, General Aviation & Rotorcraft Section, International Validation Branch, FAA, 901 Locust, Room 301, Kansas City, Missouri 64106; phone: (816) 329-4059; fax: (816) 329-4090; email: doug.rudolph@faa.gov. 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.

This AD was prompted by 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 describes the unsafe condition as inboard flap fairings aft (IFFAs) having an incorrect shape. The FAA is issuing this AD to prevent chafing between the IFFA and the front inboard tension rod, and consequent corrosion of the bare rod aluminum tube and reduced aluminum thickness. This condition, if not corrected, could lead to failure of the inboard flap drive arm, asymmetric flap extension, and reduced control of the airplane.

None.