I thought suicide was the main theory from day one.
What other possibility was there?
The other possibilities revolved around (1) someone else among the crew or passengers on board taking control, (2) a 240th individual being onboard and seizing control via the equipment area, (3) a depressurization issue taking out the pilot/co-pilot. All were weak in nature.
The key thing I believe is that when they came to the pilots house....they found that he’d set up one room with various monitors and a computer simulator system. So they went to see what flight patterns had been deleted and found that the route noted by radar....was one of the patterns that he’d flown on several occasions with the simulator.
He had become ‘depressed’ in nature over a court case in the country....involving a Muslim Mullah character, and there is some belief that he’d lost his reasoning capability with this depression.
If you take this episode and the German Airwings (2015) episode (another pilot...non-Muslim....heavily affected by depression)...it’s obvious that the stress factor is great upon these people and their jobs.