Aircraft Propulsion System Flight Test: Analysis and Evaluation Challenges and Solutions

Abstract

The paper describes the challenges and solution methodologies associated with the flight test and evaluation of the propulsion system for a twin engine military legacy aircraft. Recent flight-test programs evaluated the effects of temperature distortion and biased engine inlet total temperature measurement (TT2) on engine scheduling and compressor stability margin. The challenges are associated with the limited instrumentation and the repeatability of the flight-test points. During the test program it was necessary to employ techniques to extend the usefulness of the data beyond that provided by the acquired and reduced data sets to address the challenges associated with flight-test analysis. The challenges were addressed using mathematical models, engine cycle decks, uninstalled ground-test data, computational fluid dynamics, or some combination of these. Several specific challenges and solutions are described in detail in the paper.