Since most avionics manufacturers see software as a way to add value without adding weight, the importance of embedded software in avionic systems is increasing.
In many of these systems, failure is unacceptable. The reliability of the software running in airborne vehicles (civil or military) is shown by the fact that most air borne accidents occur due to manual errors
Unfortunately reliable software is not necessarily easy to use or intuitive, poor user interface design has been a contributing cause of many aerospace accidents and deaths