There comes a time in the life of every piston aircraft when its engines must be overhauled. There’s no exception to this rule. Based on their TBO (Time Between Overhaul) ratings, every piston engine must be removed, taken apart, checked, serviced, have components repaired or replaced as needed, and then be reassembled and reinstalled by trained professionals in order to remain in service.

Piston engine TBO is predominantly predetermined by their manufacturers, based on a combination of their hours of service and their age. Each engine manufacturer has their own specific requirements, as far as what has to be done to an engine, in order to qualify as an engine overhaul.  Whatever is specified by engine OEMs such as Teledyne Continental Motors and Lycoming, the bottom line is that a piston engine will be removed from the aircraft and shipped to an engine facility. Once there, the engine will be completely disassembled and assessed for its overall condition. Different components of the engine will also be checked to see whether they meet new tolerance standards, serviceable tolerance standards, or are unserviceable.”