New flight recorder data says Air Canada flight 759 (ACA759), an Airbus A320, descended as low as 59 feet above ground level and the 55-foot tall 787 on taxiway C before beginning to climb out on its go-around—coming potentially as close as 4 feet from a collision. At four minutes to midnight on July 7, ACA759, which had been cleared to land on Runway 28R at San Francisco International, instead lined up on taxiway C, on which three aircraft were holding for takeoff. After prompting by the one of the pilots of United flight 1 (UA1), the first in line for takeoff on taxiway C, who was well positioned to see that ACA759 was not headed towards a runway, the tower controller instructed ACA759 to go-around.
Source: avwebAir Canada Flight Misses By Four Feet