Patent ID: 9696239
Date: 2017-07-04
CPC Classifications: F01D,F02C,F05D,G01M,G07C,Y02T

Claim:
1. A method for monitoring performance of an Auxiliary Power Unit (APU) turbine efficiency of an aircraft, comprising: obtaining APU messages of multiple time points within a period; obtaining APU startup parameters including at least a rotation speed at a peak of gas temperature (EGT) according to the APU messages; calculating a percentage (NPA) of the rotation speed when the exhausting gas temperature EGT reaches its peak in the APU startup stage relative to the rotation speed in the APU normal operation; calculating an average of NPAs of the multiple time points within the period; and determining the APU turbine efficiency is in one of the stable, decline and failure phases according to the average of the NPAs.