AD 2021-04-03 Identifies The Unsafe Condition As Improperly Manufactured Cockpit And Cabin Evaporator Filters

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

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 identifies the unsafe condition as improperly manufactured cockpit and cabin evaporator filters installed during production on some PC-24 airplanes. The FAA is issuing this AD to address the unsafe condition on these products. This AD is effective March 30, 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 Pilatus Model PC-24 airplanes with certain part-numbered evaporator filter assemblies installed. The NPRM published in the Federal Register on November 23, 2020 (85 FR 74627). 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 Union. EASA has issued EASA AD No. 2020-0160, dated July 16, 2020 (referred to after this as “the MCAI”), to address the unsafe condition on Pilatus Model PC-24 airplanes.

The MCAI states:

• An occurrence was reported where, during production, cockpit and cabin evaporator filters were installed on some PC-24 aeroplanes, which were not the proper parts for the affected configuration.
• This condition, if not corrected, could degrade the fire retardant properties of the filters, possibly resulting in an increase in smoke in the cockpit/cabin in case of electrical heater over-temperature.
• To address this potential unsafe condition, Pilatus issued the [service bulletin] SB to provide replacement instructions.

For the reason described above, this AD requires replacement of affected parts with serviceable parts, as defined in this [EASA] AD, and prohibits (re) installation of affected parts.

Due to a quality escape, the fire retardant used in the original filters installed in production is not sufficient for the conditions in this configuration, which is close to the heater and blowers.

The MCAI can be found in the AD docket at https://www.regulations.gov by searching for and locating Docket No. FAA-2020-0885.

FMI: www.regulations.gov