Tuesday i spent the whole day at the Montreal/Dorval Int'l airport and something starnge happened. During the morning a 747-(200?) landed I could not see if he went to the gate or not to get his passengers off. But I have seen it in the early afternoon parked in the middle of the maintenance center, near the Royal hangar. Maybe he had some problems during his cruise to YUL and needed to be fix. Later in the day an Olympic A340 landed this one going to a gate. maybe the 747 would spend a night or more in CYUL so the airline send off another one. But the starnge thing is when that during the evening i have seen another Olympic 747 landing in montreal. Wow now that makes 3 Olympic aircrafts in YUL when they (I think) have only 1 or less flight a day in YUL. How's that there's 3 flights? Well I understand for the A340, he was a back up for the 747 at maintenance but what did the other 747 was doing there?