Guide Rod Corrosion May Lead To Inability To Adjust Prop Pitch

The FAA has released a Special Airworthiness Information Bulletin (SAIB) warning of the potential for corrosion of the guide rods on various Hartzell propellers. The FAA says the corrosion could lead to the inability to adjust the pitch of the propellers. A detailed list of effectivity can be found in Hartzell Propeller Alert Service Bulletin (ASB) HC-ASB-61-351.

At this time the FAA says the airworthiness concern is not an unsafe condition that would warrant the issuance of an AD.

The FAA says it has received reports of Hartzell guide rods, P/N A-717, which have developed extensive corrosion. The corrosion on these guide rods may cause binding in the guide collar, which reduces or prevents the propeller from changing pitch to a full feather angle. The inability to feather may lead to decreased aircraft performance in cases where an engine shuts down in flight and may be particularly dangerous if the engine is shut down during takeoff.

The agency recommends that owner, operators, and maintenance personnel follow the instructions in Hartzell ASB HC-ASB-61-351 to remove the affected part.

FMI: SAIB