The inbound flight was AC 879, an A320 from YYZ. Sitting on the taxiway C were (in order) UAL 1, a B787-900 bound for Singapore; PAL 115; an A340-300 bound for Manila; UAL 863, a B787-900 bound for Sydney; and UAL 1118, a B737-900 bound for Cancun. If all five planes had been involved, it could easily have been the greatest aviation disaster in history.