AD 2020-11-06 For Flap Actuator Taper Pins That Were Not Swaged During The Manufacturing Process

The FAA is adopting a new airworthiness directive (AD) for Pilatus Aircraft Ltd. Model PC-6, 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, PC-6/C1-H2, PC-6-H1, and PC-6-H2 airplanes.

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 flap actuator taper pins that were not swaged during the manufacturing process. The FAA is issuing this AD to require actions to address the unsafe condition on these products.

DATES: This AD is effective June 30, 2020.

Supplementary Information: The FAA issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 by adding an AD that would apply to Pilatus Aircraft Ltd. Models PC-6, 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/CH2, PC-6/C1-H2, PC-6-H1, and PC-6-H2 airplanes. The NPRM was published in the Federal Register on April 5, 2019 (84 FR 13571). The NPRM proposed to correct an unsafe condition for the specified products and was based on MCAI AD No. 2018-0235, dated November 5, 2018, issued by the European Aviation Safety Agency (EASA), which is the Technical Agent for the Member States of the European Community.

The MCAI states: During a recent overhaul, two new flap actuators were found to have taper pins installed that, apparently, had not been swaged. Investigation results identified that the taper pins had been incorrectly swaged during the manufacturing process.

This condition, if not detected and corrected, could lead to loss of one or both taper pins, consequent asymmetric flap deployment or flap surface flutter, possibly resulting in loss of control of the aeroplane. To address this potential unsafe condition, Pilatus issued the [service bulletin] SB to provide inspection instructions.

For the reason described above, this [EASA] AD requires a one-time inspection of the taper pins of the affected parts for correct installation and, depending on findings, accomplishment of applicable corrective action(s). This [EASA] AD also requires inspection of, and, depending on findings, corrective action(s) on, affected parts held as spare, prior to installation.

FMI: www.regulations.gov