Man tries to open up a door aboard a flight from Vietnam to Australia | Reference http://www.smh.com.au/nsw/drama-on-vietnam-airlines-as-man-tries-to-open-door-midflight-20141106-11hooa.html
His fear reacted to something , something he calculated to being 'realistic' to him at time, if this was 'rational' or not is the next matter ; though may also be rational based on events experienced by him that form irrationality or perceived irrationality to some extent, or events too fearful of authorities to disclose to them for calculated reasons or how it may be perceived by them, as typically happens when interviewed by police ; most generally considering their future .
The news states the man was 'clearly mentally ill' - Perhaps delusional, though delusion is usually based on references the mind forms/follows on/calculates, be it they are true or not .
In this case it sounded like he was pacing up and down isles or agitated to some degree, which means memories were impacting which tends to show that he has calculated them to realistic .
If he was on medication that was sedating they tend to alter reality which would not of helped, they can also at same time treating mental illness cause anxiety and many other problems, they are typically restricting on the body/mind and can cause displacement (you are typically displaced/disrupted normally by a plane flight to some regard varying with time spent etc.) , neural tranquilisation (anti-psychotics) can be forceful and create fear from feeling out of control or being 'altered' or fear of future impairment as mental health are also typically seen as 'impaired or be it weak' .
His memories or past events and calculation of future events/points left him having to resort to this level of 'escape' (perhaps fear of 'height' be it possibly the government or law) Fear reaction based on act committed 'is' another possibility, use of 'media distraction' as well or 'snapping point' and wanted a 'status' to perhaps be treated better or perceived in better light .
His living and surroundings could of also impacted, some are left with a bad turn of events .
I assume they would of checked him thoroughly for drugs, so calculation of 'height to 'avoid being scanned or drug check may not be an issue . He could of also engaged in illegal sex over there as can happen and was a manifestation of fear regarding it (child exploitation etc.)
