All the present operational philosophies put the flight crew at the top of the safety system.
The Crew has the final authority in the airplane and is often considered as the primary contributor in all accident investigations.
However, airplane accidents result very often from the combination of various interrelated causes and circumstances.
The figure below illustrates possible relationship between different causes.

| THALES coordinated the second formal review of the FLYSAFE project on 8 and 9 March 2006 at NLR in... |
| On the 1st of February 2005, the FLYSAFE project has started, and SKYSOFT, as one of its active... |
