Evaluation of an ARMA flutter boundary prediction method based on discrete-time structural responses to turbulence excitation in flight-tests

Aeroelastic flutter is a destructive instability phenomenon for which dedicated flight test campaigns are considered compulsory according to airworthiness regulations. In these tests, the dynamic characteristics of the aeroelastic system are interpreted from measurements of the aircraft's structural responses to external excitations. Over the years, several flutter identification and prediction techniques have been suggested in order to increase the efficiency of flutter flight tests and to enable better prediction of the flutter boundary. While most of the methods rely on external mechanical excitation accessories, the Autoregressive Moving-Average (ARMA) flutter prediction method attempts to identify the aeroelastic system based on the aircraft structural response to random air turbulence excitation. The current study evaluates the ARMA flutter prediction method using flight test data of three operational platforms, namely an Unmanned Air Vehicle (UAV), and the F-16 and F-15 fighter aircrafts. A post-processing procedure for the identification and treatment of poorly evaluated data samples is also outlined.