EASA SIB CASA-2020-09
Pratt & Whitney Canada PW901A and PW901C Auxiliary Power Units - Fires
Summary
The Transport Canada Civil Aviation Safety Alert CASA 2020-09 addresses fire risks associated with Pratt & Whitney Canada PW901A and PW901C auxiliary power units (APUs). It highlights issues with the starter clutch mechanism that can lead to APU fires, affecting aircraft equipped with these APUs. The alert provides safety information relevant to owners, operators, and maintainers of these units.
What Changed
This safety alert introduces awareness of starter clutch re-engagement or failure to disengage after APU start-up, which has caused fires. It identifies potential maintenance discrepancies affecting lubrication and durability of the starter components. Pratt & Whitney Canada, Labinal Power (Safran), and Boeing have implemented improvements to the Instructions for Continued Airworthiness to address these issues.
Why It Matters
This alert is critical for aviation professionals because improper maintenance of PW901A and PW901C APU starters can lead to overheating and fires, posing safety risks. Operators and maintenance organizations must understand and apply updated maintenance instructions to prevent these hazardous events and ensure continued airworthiness. Compliance helps reduce risk and maintain operational safety.
What To Do
Operators and maintainers should review and follow the instructions in Pratt & Whitney Canada Service Information Letter PW900-24R1, available on the Pratt & Whitney website. They must maintain the PW901A and PW901C APUs according to the latest Instructions for Continued Airworthiness. For further information, stakeholders can contact Transport Canada or the designated continuing airworthiness office.