I am a airline pilot who wants to observe fasting in Ramadan. At times I am unable to fast on a a long flight due to not being 100% mentally present during critical phases of flight god forbid there is an emergency. My question is that if the flight starts at 5:00 pm and two hours remain for iftar for example can I break my fast before starting the flight to be mentally aware before takeoff, or I have to wait after takeoff to break my fast and avail the travellers concession. This is because if I wait till after takeoff I have been fasting since morning and hence may not be able to perform 100% in case of an emergency since the lives of my passengers also depend on my alertness? I would appreciate an answer on this.