Lycoming Boosts Time Between Overhaul to 2,600 Hours

Lycoming Engines has released Service Instruction (SI) 1009BF, which outlines increased recommended time between overhaul (TBO) intervals for a variety of piston aircraft engines. While SI 10009BF expands many engines’ TBO hours from 2,000 hours to 2,600 hours, Lycoming retained its recommendation for 12-year calendar TBO intervals.

The longer 2,600-hour TBO applies to O‑320, IO‑320, O‑360, IO‑360, IO‑390, O‑540, and IO‑540 series engines “when operated and maintained in accordance with all applicable Lycoming technical publications and FAA airworthiness requirements.” This means, according to SI 10009BF, the TBO extensions do no apply to engines that incorporate “other than genuine Lycoming parts” or parts or engines that “have been maintained or overhauled using methods other than Lycoming-approved procedures.”

It appears that Lycoming no longer addresses the possibility of using parts manufactured under FAA parts manufacturer approval (PMA) regulations. The latest version of the service instruction removes language in the previous version (SI 1009BE) that mentions “FAA-PMA parts [that] have not been approved for use by Lycoming (contact Lycoming for information regarding FAA-PMA parts approved for use by Lycoming).”

According to Lycoming, “Extended intervals are backed by endurance testing and fleet data confirming strong durability under compliant operating conditions.”

There is a growing movement among owners and maintainers of piston aircraft engines to run engines well beyond manufacturers’ recommended TBOs, based on continuous monitoring of engine health indications, including oil analysis and borescope inspections. Engine manufacturer TBOs are not regulatory mandates, unless incorporated in operating specifications for certain types of commercial operations.

cHowever, South Africa recently changed its policies and now requires compliance with TBO limitations for all operators. Lycoming’s 2,600-hour TBO should provide some relief for aircraft owners in South Africa, although the 12-year limit still would apply.

“Lycoming’s updated TBO schedule represents our ongoing focus on delivering maximum value, reliability, and performance to aircraft owners, operators, and maintainers,” said Lycoming Engines senior v-p Jim Wright. “This enhancement reflects decades of engineering experience combined with the latest fleet data.”