AD 2020-26-19 Requires Revising The ALS Of The Existing Aircraft Maintenance Manual

The FAA is adopting a new airworthiness directive (AD) for all Pilatus Aircraft Ltd. Model PC-7 airplanes. This AD results from mandatory continuing airworthiness information (MCAI) originated by an aviation authority of another country to identify and correct an unsafe condition on an aviation product.

This AD requires revising the Airworthiness Limitations section (ALS) of the existing aircraft maintenance manual (AMM) to introduce new mandatory repetitive inspections for the flap pivot arm assemblies and for certain wing angle brackets, and to implement a change to the Oxygen cylinder and pressure reducer task item. The FAA is issuing this AD to address the unsafe condition on these products. This AD is effective March 29, 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 Aircraft Ltd. Model PC-7 airplanes. The NPRM published in the Federal Register on September 24, 2020 (85 FR 60097). The NPRM was prompted by MCAI originated by the Federal Office for Civil Aviation (FOCA), which is the aviation authority for Switzerland. FOCA has issued FOCA AD HB-2020-007, dated July 23, 2020 (referred to after this as the MCAI), to correct an unsafe condition with new mandatory instructions for continued airworthiness for all Pilatus Aircraft Ltd. Model PC-7 airplanes.

The MCAI states:

• The airworthiness limitations and certification maintenance instructions for Pilatus PC-7 aeroplanes, which are approved by FOCA, are currently defined and published in the Pilatus PC-7 AMM Chapter 5. These instructions have been identified as mandatory for continued airworthiness.
• Failure to accomplish these instructions could result in an unsafe condition [discrepancies of life-limited and overhauled components, which could result in reduced structural integrity and system reliability of the airplane].
• Previously, FOCA issued AD HB-2019-004 (later corrected) to require implementation of the maintenance tasks and airworthiness limitations as specified in Pilatus PC-7 AMM Document Number 01715, or Document Number 02416, both at issue 44, as applicable. [These tasks included the added wing angle bracket at rib 23 repetitive inspections.]
• Since that AD was issued, Pilatus amended the ALS, as defined in this AD, to introduce new mandatory repetitive inspection for the flap pivot arm assemblies and a change to the Oxygen cylinder and pressure reducer task (Chapter 35–Oxygen) to remove the reference to the part numbers.
• For the reason described above, this [Swiss] AD retains the requirements of FOCA AD HB-2019-004 including its correction, which is superseded, and requires accomplishment of the actions specified in the ALS.

You may examine the MCAI in the AD docket at www.regulations.gov by searching for and locating Docket No. FAA-2020-0849.

The NPRM proposed to require revising the ALS of the existing AMM to introduce the new mandatory repetitive inspections for the flap pivot arm assemblies and for certain wing angle brackets, and to implement a change to the Oxygen cylinder and pressure reducer task item. The FAA is issuing this AD to address the unsafe condition on these products.

FMI: www.regulations.gov