Lycoming engine owners spared expensive piston pin plug AD through cooperative AOPA/FAA efforts
Thousands of Lycoming engine owners have been spared an expensive piston pin plug airworthiness directive (AD) thanks to a cooperative effort between Federal Aviation Administration aircraft certification services and the Aircraft Owners and Pilots Association.
Instead of an AD, the FAA has issued a special airworthiness information bulletin (SAIB)—requested by AOPA—recommending that owners of Textron Lycoming engines manufactured or overhauled within the past five years take steps to check for excessive piston pin wear.
“Thousands of owners have been spared the potential expense and aggravation of having to tear down their engines to inspect or replace piston pin plugs because the FAA opted for an SAIB instead of an airworthiness directive,” said Douglas C. Macnair, AOPA director of certification and regulatory policy.
“The FAA’s New England Engine and Propeller Directorate and the New York Aircraft Certification Office are showing a real willingness to use non-regulatory means to solve service problems efficiently and inexpensively. That’s a tremendous benefit to AOPA members.”
The problem is an unusually high wear rate on piston pin plugs in Textron Lycoming engines manufactured (or overhauled with Lycoming cylinder kits) after 1994. The problem is even more pronounced in engines shipped after October 1997. There have been two engine failures due to excessive wear.
Embry-Riddle Aeronautical University recently grounded their fleet of new Cessna 172s with Lycoming engines following evidence of excessive wear and an engine failure. That prompted the FAA to consider issuing an AD.
AOPA agreed with the FAA that excessive piston pin plug wear constituted a potential safety hazard. But AOPA suggested that an owner could detect a wear problem long before it caused engine failure. Therefore, an AD requiring an engine tear down wasn’t necessary.
The FAA reviewed AOPA and industry supplied data. It concluded that there was a low probability of engine failure if owners followed a proactive maintainence plan.
A SAIB outlining that maintenance plan has been sent to all affected owners. It recommends that the owner make frequent oil changes (first oil change at 10 hours, next at 25 hours, and subsequent oil changes every 50 hours), inspect the oil filter for aluminum or iron particles, and use spectroscopic oil analysis to monitor engine component wear rates.
“Compliance with an SAIB is not legally mandatory,” said Macnair, “but AOPA strongly encourages owners of affected Textron Lycoming engines to follow the procedures outlined in the SAIB.”
The 345,000-member Aircraft Owners and Pilots Association is the world’s largest pilot organization. Its watch on airworthiness issues is part of AOPA’s efforts to control the cost of flying.
April 9, 1999