@ txl : Excellent informative post , alwas nice to hear how other work., even if I do not necessarily agre with your conclusion.
We have no idea if MH370 was a suicide or not , probable, yes but there are dozen of other hypothesies and in any case both pilots did not have any issiues with their manageent . . Silk air was about debts if I recall well, .the morrocan one was a girl friend issue, etc..on Germanwings/Lubitz , I know a bit more that the average and it had nothing to do with his employer or his working conditions , but about the fear of losing his licence and failing in his only goal in life .
Mental illness is a difficult subject to get into..
Also it would seem that taking a gun and shooting people as a form of suicide is more a US thing . In other contries people with a grunge at their management and being mentally ill , generally commit suicide on their worklplace , e.g. lots of police officers do this, or taking theFrance Telecom /Orange example in France , jumping out ow their office window. a bit of additional info here :
https://hbr.org/2009/10/why-are-france-telecom-workers in English .