AD 2021-11-08 Requires An Eddy Current Inspection Of Each Fuselage Wing Fitting

The FAA is superseding Airworthiness Directive (AD) 2014-25-04 for all Pilatus Aircraft Ltd. (Pilatus) Model PC-6, PC-6-H1, PC-6-H2, PC-6/350, PC-6/350-H1, PC-6/350-H2, PC6/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.

AD 2014-25-04 required incorporating revised airworthiness limitations into the aircraft maintenance manual (AMM) for your FAA-approved maintenance program. This AD requires incorporating new airworthiness limitations and an eddy current inspection of each fuselage wing fitting if an earlier version of the service information was accomplished. This AD was prompted by a determination that the new life limits, revised airworthiness limitations, and new inspection procedures are necessary. The FAA is issuing this AD to address the unsafe condition on these products. This AD is effective July 12, 2021.

Supplementary Information: The FAA issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 to supersede AD 2014-25-04, Amendment 39-18045 (79 FR 73803, December 12, 2014) (AD 2014-25-04). AD 2014-25-04 applied to all Pilatus Model 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 and resulted 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. AD 2014-25-04 required incorporating revised airworthiness limitations into the AMM for your FAA-approved maintenance program.

The NPRM published in the Federal Register on October 2, 2020 (85 FR 62266). The NPRM was prompted by a MCAI issued by the European Union Aviation Safety Agency (EASA), which is the Technical Agent for the Member States of the European Union. EASA superseded its previous MCAIs on this unsafe condition with EASA AD 2020-0120, dated May 27, 2020 (EASA AD 2020-0120). The NPRM proposed to require revising the airworthiness limitation section of the existing maintenance manual or instructions for continued airworthiness to incorporate new airworthiness limitations, and performing an eddy current inspection of the fuselage wing fittings and wing to fuselage fittings.

After the FAA issued the NPRM, EASA superseded EASA AD 2020-0120 and issued EASA AD 2020-0278, dated December 14, 2020 (EASA AD 2020-0278) (also referred to after this as “the MCAI”). According to EASA AD 2020-0278, an installation procedure specified in the service information identified in the NPRM contained an error and, therefore, did not adequately address the identified unsafe condition. Pilatus revised the airworthiness limitations and issued corrected service information, which includes installing certain bushes using grease instead of a bonding agent and an additional one-time eddy current inspection of the fuselage wing fittings and wing-to-fuselage fittings if the last inspection was performed using an earlier version of the service information. You may examine the MCAI in the AD docket at https://www.regulations.gov by searching for and locating Docket No. FAA-2020-0857.

The FAA issued a supplemental notice of proposed rulemaking (SNPRM) to amend 14 CFR part 39 to supersede AD 2014-25-04. The SNPRM published in the Federal Register on March 8, 2021 (86 FR 13222). The SNPRM proposed to add an eddy current inspection of each fuselage wing fitting if an earlier version of the service information was accomplished. The FAA is issuing this AD to address reduced airplane controllability due to possible loss of structural integrity of certain parts.

FMI: www.regulations.gov