EASA AD CF-2019-05
Engine Control - Fuel Control Unit Galvanic Corrosion Contamination
Summary
Canadian Airworthiness Directive CF-2019-05 addresses galvanic corrosion contamination in the Fuel Control Unit (FCU) of Pratt & Whitney Canada PT6B-37A engines, serial number PCE-PU0289 and earlier. The directive mandates replacement of affected FCUs to prevent engine control loss and potential inflight shutdowns. This AD aims to enhance engine reliability and safety for operators using these specific engines.
What Changed
CF-2019-05 introduces a mandatory replacement of FCUs susceptible to galvanic corrosion as detailed in Pratt & Whitney Canada Service Bulletin 39107. It establishes compliance requirements based on FCU service hours and age, ensuring affected units are replaced within specified timeframes to mitigate unsafe conditions.
Why It Matters
This directive is critical for aviation professionals because galvanic corrosion in the FCU can lead to engine over-speed and inflight shutdown, posing serious safety risks especially for single-engine helicopters. Compliance helps maintain engine performance and prevents emergency autorotation landings, thereby protecting passengers and crew. Maintenance and compliance teams must track FCU service times closely to meet regulatory requirements.
What To Do
Operators of PT6B-37A engines with FCUs of pre-Service Bulletin 39107 configuration must replace the FCU within six months if it has accumulated 1500 hours or six years since new or overhaul. For FCUs with less than 1500 hours or six years, replacement must occur before reaching these limits. All replacements must follow the instructions in P&WC SB PT6B-72-39107R1 or later approved revisions.
Your fleet's weekly compliance brief
AI-summarized regulatory changes, compliance deadlines, and action items — filtered to your aircraft, every Monday.
AI-generated summary from official EASA source document. Always verify against the original.