The U.S. National Transportation Safety Board says the Air Canada A320 that lined up on a taxiway at San Francisco Airport last month instead of a runway descended to 59 feet AGL before climbing out of danger. The tails of the airliners on the taxiway would have been close to that height as the SFO tower called a go around and the Air Canada crew hit the power. According to a preliminary report from the NTSB, Flight 759 from Toronto to San Francisco was 88 feet above the runway when the throttles were advanced and it sunk a further 29 feet before recovering from the descent.
Fortunately, the perilously low descent happened in a gap between the second and third of four airliners getting ready to take their turns for takeoff. According to the NTSB, the Air Canada crew thought they were lined up for Runway 28R and that the runway they intended to land on was Runway 28L, which was actually closed at the time. “(The flight crew) also stated that they did not recall seeing aircraft on taxiway C but that something did not look right to them,” according to the NTSB. A United Airlines crew alerted the tower to the error and a Philippine Airlines crew flashed landing lights at the approaching Airbus in a last ditch warning.