Originally Posted by
Swanhunter
Anywhere between 5 mins and hours depending on time of day, the terminals, the weather. Anything between terminals (like your T4 to T3) is always a bit painful as to requires a bus transfer which in this case actually goes under one of the main runways. 90mins should be OK but won't leave a huge amount of time.
So there's a chance that we might miss the flight if everything doesn't go off without a hitch? How much of a time margin are they leaving here?