Time between overhaul
Encyclopedia
One important measure of an aircraft engine
's overall economics is how often it has to be overhauled, the so-called time between overhaul, typically seen as TBO or TBOH.
The time between overhauls is generally a function of the complexity of the engine. Piston-based engines are much more complex than their turbine-powered cousins, and generally have TBO's 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 engine
s and turboprop
s often have TBO's on the order of 3,000 to 5,000 hours.
Since the overhaul process requires the engine to be taken apart, it is typically an expensive process. The value of a used engine decreases if it is close to requiring 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 how the aircraft is being operated, overhauling the engine at this time is not necessarily mandatory. For aircraft used for non-commercial purposes overhauls are not mandatory, but highly recommended. Likewise, the TBO time recommended doesn't guarantee that the engine will last that long.
Aircraft engine
An aircraft engine is the component of the propulsion system for an aircraft that generates mechanical power. Aircraft engines are almost always either lightweight piston engines or gas turbines...
's overall economics is how often it has to be overhauled, the so-called time between overhaul, typically seen as TBO or TBOH.
The time between overhauls is generally a function of the complexity of the engine. Piston-based engines are much more complex than their turbine-powered cousins, and generally have TBO's 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
Turbocharger
A turbocharger, or turbo , from the Greek "τύρβη" is a centrifugal compressor powered by a turbine that is driven by an engine's exhaust gases. Its benefit lies with the compressor increasing the mass of air entering the engine , thereby resulting in greater performance...
. In comparison, jet engine
Jet engine
A jet engine is a reaction engine that discharges a fast moving jet to generate thrust by jet propulsion and in accordance with Newton's laws of motion. This broad definition of jet engines includes turbojets, turbofans, rockets, ramjets, pulse jets...
s and turboprop
Turboprop
A turboprop engine is a type of turbine engine which drives an aircraft propeller using a reduction gear.The gas turbine is designed specifically for this application, with almost all of its output being used to drive the propeller...
s often have TBO's on the order of 3,000 to 5,000 hours.
Since the overhaul process requires the engine to be taken apart, it is typically an expensive process. The value of a used engine decreases if it is close to requiring 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 how the aircraft is being operated, overhauling the engine at this time is not necessarily mandatory. For aircraft used for non-commercial purposes overhauls are not mandatory, but highly recommended. Likewise, the TBO time recommended doesn't guarantee that the engine will last that long.