Communication to : AGARD/FDP Joint International Conference on 'Aircraft Flight Safety - Actual Problems of Aircraft Development', Zhukovsky (Russia), August 31 - September 5, 1993SIGLEAvailable at INIST (FR), Document Supply Service, under shelf-number : 22419, issue : a.1993 n.138 / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc