As far as I remember, the Air India 747 which was brought down by the terrorists off Shannon way back in 1985, was ferrying a fifth inoperative engine. I think the extra time takebn for this procedure while on ground at YYZ
(or was it during the stop pver at YMQ?) ultimately proved disastrous l as the subsequent delay meant the aircraft exploded off Shannon. If it was running on time, then the explosion would have happened while on ground at LHR
(which seemrd to be the terrorists intention - as another bomb exploded at Narita on the same day while the bags were being transferred from a CP
Air flight to an Air India one).
[Edited 2005-02-10 07:42:45]