The Federal Aviation Administration has proposed a $60,000 civil penalty against Lycoming Engines, the Williamsport, Pennsylvania piston engine manufacturer, over alleged violations of federal aircraft maintenance rules. The agency announced the action on August 26, 2026.
The allegations center on work the company's repair station performed on four Lycoming TEO-540-C1A engines in September 2024. According to the FAA, the shop departed from the manufacturer's own maintenance manual while servicing the units. The agency alleges specifically that the Exhaust Bypass Valve Assemblies went unreplaced before the four engines were approved for return to service, a step the manual requires.
The FAA did not indicate whether the alleged lapses led to any in-service incident or safety event involving the affected engines. Lycoming has 30 days from receipt of the enforcement letter to respond, a standard window that allows a company to contest the findings, submit additional records, or negotiate a reduced amount.
Return-to-service documentation sits at the center of most FAA repair station enforcement cases. Part 145 certificate holders are required to perform maintenance according to current manufacturer instructions and to record each step before releasing a component back into the fleet. Actions of this size take the form of civil penalties and stop short of certificate suspension. They typically follow a routine surveillance audit or a records review rather than an accident investigation. Lycoming builds piston powerplants used widely across the general aviation fleet, and the TEO-540 line is a turbocharged, electronically controlled variant aimed at newer airframe programs.
Source: FOX56 - https://fox56.com/news/local/faa-proposes-60k-fine-against-lycoming-engines-over-maintenance-violations