Pushrods

The number 3 cylinder exhaust pushrod broke, due to a valve stuck in the closed position. The valve was not stuck at the time of the investigation. No marks were seen on the top of the piston as viewed through a borescope. The lifter came apart as a result of the broken push rod but appears to have been operating properly prior to the event.

Editorial Staff

Wednesday, May 17, 2017 at 12:00 AM ET

Verified

Key Takeaways:

Multiple aircraft types reported various pushrod failures, encompassing abnormal wear, breakage, bending, and manufacturing defects.
Common cylinder pushrod issues included extensive wear, often affecting rocker arms and sometimes linked to insufficient lubrication.
Specific incidents highlighted a broken exhaust pushrod caused by a stuck valve and bent aileron control rod ends lacking proper maintenance guidance.
A critical manufacturing defect was identified where pushrods were not drilled, preventing essential oil flow to engine components.