But my field of interest happens to be Human Performance in Aviation, or the lack of it.
This person should never have been near an aircraft , never mind flying one!
Some knew this but chose to turn the blind eye, that is a crime.
His father must have known or should have.
I don't speak German well enough to appreciate Lubitz senior's perspective. But speaking generally, a very high proportion of people suffer from psychiatric problems at some point in their lives and few go on to kill themselves, let alone anyone else. The lifetime prevalence of major depression is 20-30% depending on which figures you look for.
Now, there are clearly several types of depression (and related illnesses). Certainly some stories about Lubitz suggest that his illness was unusual and should have raised red flags
if they are true as reported. However speaking more generally, people who kill themselves often do surprise friends and family. Also, the brighter you are, the more unwell you can get whilst still seemingly holding things together. And even if families know about a person's low mood, it's not uncommon for it to seemingly improve shortly before they decide to kill themselves - presumably due to the newfound sense of purpose.
And , no, I am not privy to any information You dont have.
In that case I'm afraid I find your comments both ignorant and disrespectful - not so much to Lubitz' father about whom I know very little, but with regard to the bereaved relatives of people who have killed themselves in general. The writing isn't always on the wall, and even when it is, it can sometimes only be read in retrospect.