AD/PA-42/2 - Nacelle Fuel Tank Check Valve - Installation - CANCELLED

This document officially cancels a previous aviation safety rule that applied to owners of Piper PA-42 Cheyenne III aircraft.

What it used to require: Previously, the Civil Aviation Safety Authority (CASA) mandated that owners install special one-way valves (called check valves) in the nacelle fuel tanks (the fuel tanks housed in the streamlined engine coverings) within 100 flight hours after June 1983. This was to prevent fuel from flowing backward or draining improperly.

What changed: As of 9 April 2009, this requirement is completely cancelled. Aircraft owners no longer need to install these valves to comply with this specific rule.

Why it matters: If you own or operate a Piper PA-42 Cheyenne III, this cancellation means one less regulatory requirement to track. However, you must still comply with other applicable airworthiness directives and the manufacturer’s latest guidance.