Aircraft piston engines on-condition exploitation

Abstract

PurposeCurrently, in many countries, aviation safety regulations allow piston engines exploitation above Time Between Overhaul (TBO) recommended by manufacturers. Upon fulfillment of certain requirements, which are already included in the manufacturers’ documentation, TBO extension is granted. National Aviation Authority has approved exploitation of piston engines to something like quasi on-condition maintenance, which has no technical proof behind. This leads to the conclusion that the current, simple way of the engine’s life extension is not the best solution for maintaining flight safety. Aircraft piston engines TBO extension requires changes in the current exploitation system.Design/methodology/approachThe paper provides methodology for aircraft piston engines on-condition exploitation based on engine flight parameters (from cruise and takeoff) and engine oil particles analysis. The paper describes a method of diagnostic limits for certain engine parameters and elements in the oil assignation assuming that they come under rules of normal distribution.FindingsIt has been found that piston engines installed on maximum takeoff mass <5,700 kg class aircraft are the second biggest contributor as a source of aviation events, thereby having a significant impact on aviation safety. Engine flight parameters and elements content in the oil meet Gaussian rules.Practical implicationsIntroduction of the engine on-condition exploitation into operation practices reduces the operator’s engine direct maintenance cost and increases technical knowledge of the employees and has a positive impact on flight safety.Originality/valueIt is the first scientific description in Poland, which proposes an empirically proved methodology of the aviation piston engines on-condition exploitation.