Work and rest
It is is tempting to sell productivity (in terms of hard earned extra pilot agreements of the past) for a new pay or pension deal.
The result can be a two pilot operation on sectors of 10 to 12 hours or more.
This can lead to a creeping fatigue that builds up over the work pattern.
A pilot with stress (domestic or otherwise and sometimes difficult to detect when it is yourself) is already headed for a breakdown.
He is like a teapot that is nearly full of domestic stress and / or relationship problems before he starts. Add to this lack of sleep and fatigue because of a two crew operation and then the teapot overflows ... a classic nervous breakdown when irrational behaviour starts to happen.... the flow is reversed.
Airlines need to consider duty hours and crewing very carefully.
Retired 747 P1