Cockpit Voice Analysis and Diagnostic Based on Conditional Rules &amp; Fault Tree Analysis

Lin Zhang Ji

doi:10.4172/2168-9792.1000104

Abstract

The characteristics of cockpit voices (sounds) recorded by Cockpit Voice Recorder (CVR) are key evidences in investigating accident causes for wrecked airplane. In order to analyzing and diagnosing wrecked airplane causes through cockpit voices in CVR, some researchers are made as followings in this paper: Firstly, some typical background sounds of cockpit voices, such as wind shear audio, near-earth audio warning, take-off form of audio warning, fire alarm and so on, are obtained and classified through listening and distinguishing by adobe audition audio software in laboratory. Then, the characteristics of these background sounds are extracted by signal analyses methods such as Fourier Transform (FT), Wavelet Transform (WT), and so on. Through these methods, the special characteristics are depurated, such as frequency value, spectral density, and frequency line numbers. Thirdly, as the key part of the paper, conditional rules and fault trees principles focuses on and applied in order to distinguish and diagnose these special characteristics for approximate or different background sounds of cockpit voices. And some available results are obtained finally. Through all these above researches, new analyzing and diagnosing approaches are put forward, which are suitable for accurate grasping the cause of flight accident and analyses and diagnose flight accident. All the researches and conclusions have a certain reference for analysis and diagnosis of flight accidents, and protect flight security.

Highlights

Both CVR and Flight Data Recorder(FDR) are composed the Aircraft Black Box (Figure 1) [1], which is essential airborne equipment for modern commercial aviation aircraft, and plays an irreplaceable role in the aircraft accident investigation and wrecked airplane’ cause analyses.The Cockpit Voice Recorder (CVR) records many kinds of sounds during flight, which is called as cockpit voice in the professional
It is very important for us to obtain and accurately analyze the different characteristics of background sounds in the investigation of flight accidents and incidents, which are directly related to the safety of aircraft flight
Building fault trees based on conditional rules: Here, some typical cockpit voice background are chosen, such as wind shear audio, near-earth audio warning, take-off form of audio warning, fire alarm and so on

Summary

Introduction

Both CVR and Flight Data Recorder(FDR) are composed the Aircraft Black Box (Figure 1) [1], which is essential airborne equipment for modern commercial aviation aircraft, and plays an irreplaceable role in the aircraft accident investigation and wrecked airplane’ cause analyses.The Cockpit Voice Recorder (CVR) records many kinds of sounds during flight, which is called as cockpit voice in the professional. Through the figure 2, listening & distinguishing, and above timefrequency analysis principle under the environment of MATLAB, we can get the information of a variety of cockpit voice background sound characteristics (Table 1). It is very important and focused on how to distinguish the similarities and differences of characteristics of typical cockpit voice、contrast to the standard cockpit voice samples, in order to analyze & diagnose unknown cockpit voice、and provide the basis for analysis and diagnosis the causes of aircraft accidents.

Results

Conclusion