AD 2021-06-01 Prompted By A Report That Electronic Circuit Breakers (ECBs) Were Found In A Locked State

The FAA is adopting a new airworthiness directive (AD) for all Pilatus Aircraft Ltd. (Pilatus) Model PC-24 airplanes.

This AD was prompted by a report that electronic circuit breakers (ECBs) were found in a locked state after maintenance, but before flight. This AD requires revising the airplane flight manual (AFM) to incorporate a procedure to check for the ECB status. The FAA is issuing this AD to address the unsafe condition on these products. This AD is effective May 4, 2021.

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 all Pilatus Model PC-24 airplanes. The NPRM published in the Federal Register on October 23, 2020 (85 FR 67465). The NPRM was prompted by MCAI originated by the European Union Aviation Safety Agency (EASA), which is the Technical Agent for the Member States of the European Community. EASA has issued EASA AD No. 2020-0096, dated April 29, 2020 (referred to after this as “the MCAI”), to correct an unsafe condition for Pilatus Model PC-24 airplanes.

The MCAI states:

• An occurrence was reported where, before take-off after maintenance of a PC-24 aeroplane, some electronic circuit breakers (ECB) were found in a “LOCKED” state.
• This condition, if not corrected, could lead to a loss of power supply to equipment, without indication to the flight crew before take-off.
• To address this potential unsafe condition, Pilatus issued the AFM [temporary revision] TR, as defined in this [EASA] AD, to provide operators with the necessary preflight check instructions.
• For the reason described above, this [EASA] AD requires amendment of the AFM.

You may examine the MCAI in the AD docket at https://www.regulations.gov by searching for and locating Docket No. FAA-2020-0917.

In the NPRM, the FAA proposed to require revising the AFM to incorporate a procedure to check for the ECB status. The FAA is issuing this AD to address the unsafe condition on these products.

FMI: www.regulations.gov