METHODOLOGY TO EVALUATE AIRCRAFT PISTON ENGINE DURABILITY

A main problem in aircraft engines is the evaluation of residual life to TBO. The algorithm described in this paper calculates with good reliability the residual life to TBO of a petrol piston engine. The method was tested on small last-generation naturally-aspirated-avio piston engine, and has demonstrated to be effective in several experimental tests. This method is implemented directly in the FADEC or ECU of the engine with very few lines of C-Code. The method can be used also in many industrial engines. This innovative method assumes that only two main factors (load and wear) affect engine durability or Time Between Overhauls (TBO). These two factors are considered as separate and combined with the worst case criteria. The load is assumed to follow a logarithmic law and a formula similar to the Miner‟s law for material fatigue is used, making possible to calculate the “load curve” with the knowledge of only two points. The “wear” curve is related to elapsed engine cycles, and is easy to implement since it is related to technological. The resulting algorithm is very simple and can be implemented in very few software lines with data collected from the already existing sensors.