The main objective of this study is to establish a method for deriving engine mission duty cycles.Seven typical training profiles of a trainer engine are recorded.The flight mission mix is obtained from statistics of the trainer engine operations on fields.Based on the typical flight mission profiles and the mission mix

the mission duty cycles of the trainer engine are derived which can be used as a design load requirements for a new trainer engine.This study showes that due to short average flight time

a great difference exists between the mission duty cycles of the trainer engine and the design requirements of Engine Structural Integrity Standard (MIL-STD-1783).