Engine Overhaul (OHL) & Rebuilt

Time between overhaul (abbreviated as TBO or TBOH) is the manufacturer’s recommended number of running hours or calendar time before an aircraft engine or other component requires overhaul.

On rotorcraft many components have recommended or mandatory TBOs, including main rotor blades, tail rotor blades and gearboxes.

For engines the time between overhauls is generally a function of the complexity of the engine and how it is used. Piston-based engines are much more complex than turbine-powered engines, and generally have TBOs on the order of 1,200 to 2,000 hours of running time. They tend toward the lower number if they are new designs, or include boosting options like a turbocharger. In comparison, jet engines and turboprops often have TBOs on the order of 3,000 to 5,000 hours.

Since overhauling needs the engine to be taken apart, it is typically expensive. The value of a used engine decreases if it is close to needing an overhaul, so used engines (and aircraft) typically list their time since overhaul or TSOH.

The TBO is a time ‘recommended’ by the manufacturer and, depending upon what rules the aircraft operates under, overhauling the engine at this time is not necessarily mandatory. For aircraft used non-commercially overhauls are not mandatory, but highly recommended. Likewise, overhaul at the recommended TBO does not guarantee that the engine will last that long.

Overhauled Engines

We, Aircraft Supports, LLC is a company who built your engine knows it best. We tests overhauled engines to manufacturer’s standards, not just the minimum accepted values. With Aircraft Supports, LLC overhauled engines you can fly with confidence knowing we built your engine to manufacturer’s reliability standards.

Rebuilt Engines

We built your engine, so we know it best. We offer piston engine services at a level of reliability, durability, and support in which others cannot compete.

Get an absolute zero-time engine from Aircraft Supports, LLC; we use only the original engine manufacturer that can rebuild your engine to meet the exact, new engine specifications that a rebuilt engine requires. Our rebuilt engines are built on the same assembly line as new and overhauled engines, following the same quality processes and manufacturing standards.

Commonly Used Engines

Lycoming Aero Engines

Lycoming is a major American manufacturer of aircraft engines. Headquartered in Williamsport, Pennsylvania, Lycoming produces a line of horizontally opposed, air-cooled, four-, six- and eight-cylinder engines including the only FAA-certified aerobatic and helicopter piston engines on the market.

The company has built more than 325,000 piston aircraft engines and powers more than half the world’s general aviation fleet, both rotary and fixed wing. The company is currently part of Textron’s Avco Corporation.

Continental Aero Engines

Continental Motors, Inc. is an aircraft engine manufacturer located at the Brookley Aeroplex in Mobile, Alabama, United States. It was originally spun off from automobile engine manufacturer Continental Motors Company in 1929 and owned by Teledyne Technologies until December 2010.

The company is now part of Aviation Industry Corporation of China, which is owned by the government of the People’s Republic of China.

Williams Aero Engines

The Williams FJ44 is a family of small, two-spool, turbofan engines produced by Williams International/Rolls-Royce for the light business jet market. Until the recent boom in the very light jet market, the FJ44 was one of the smallest turbofans available for civilian applications.

Although basically a Williams design, Rolls-Royce was brought into the project, at an early stage, to design, develop and manufacture an air-cooled high-pressure (HP) turbine for the engine. The FJ44 first flew on July 12, 1988 on the Scaled Composites/Beechcraft Triumph aircraft.

The Williams FJ33 is a smaller engine based on the basic FJ44 design.

Rotax Aero Engines

Rotax supplies aircraft engines for ultralight aircraft, light aircraft and unmanned aerial vehicles. Rotax engines designed specifically for light aircraft include both four-stroke and two-stroke models.
Current models are:

Rotax 912 series, four-stroke

Rotax 914 series, four-stroke

Rotax 915 series, four-stroke

Rotax 582 UL, two-stroke

The Rotax 914 is a turbo-charged, four-stroke, four-cylinder, horizontally opposed aircraft engine with air-cooled cylinders and water-cooled cylinder heads. It is designed and built by the Austrian company BRP-Powertrain, owned by BRP, as part of its Rotax brand. The engine commonly powers certified light aircraft, homebuilt aircraft, autogyros and military UAVs such as the MQ-1 Predator.