Military mental health troubles are not confined to flying. A close relative, serving in Royal Navy submarines, tells me that at least one crew member, and sometimes more, goes 'wibble' ( as he calls it) on most deployments. And easy direct contact with the outside world (and thus help) is not usually allowed or even practically possible from a submarine. Violence and suicide on board are not unknown. (eg the shooting of the first lieutenant on HMS AMBUSH)