Much is being said about the crash of Germanwings’ flight 4U9525, including the fact that the co-pilot was somehow responsible for this. It is not always possible to exactly identify the cause in accidents of this sort, but there is fairly strong evidence in several instances which have not been highlighted in the press so far. This list appears to be more exhaustive:
This seems to draw mainly from the site: http://aviation-safety.net/ One can also see the Wikipedia articles for more details of the respective incidents.
There is even one from India which did not get much publicity as it was not a commercial flight:
And of course, something of this sort might have happened in the case of MH 370 although there are several other theories which can explain its disappearance.