Oscillation mode flight data analysis based on FFT

Purpose: The purpose of this paper is to propose an identification method of acquiring aircraft mode characteristics based on fast Fourier transform and half-power bandwidth method, aiming at the common oscillation met in flight test. Design/methodology/approach: The feasibility of this method is demonstrated through derivation; the robustness analysis is conducted through three examples, and finally the method was applied on a set of sideslip angle record from flight test. Findings: The derivation and numerical analysis both show that the presented method can have high accuracy and good robustness under coupled mode and noise condition. Practical implications: The method proposed is of robustness, and it is concise and easy to apply on flight data record. Originality/value: This paper demonstrates the feasibility of half power bandwidth to be applied on oscillation mode characteristics identification from flight data record, which is different from other method applied.