Air Canada Flight 759 descended less than 100 feet above planes taxiing next to the runway at San Francisco International Airport before pilots abandoned the landing, as revealed in pictures released Wednesday by federal investigators.
Air Canada's Airbus A320 had been cleared to land July 7 just before midnight, but the pilots lined up and descended on the adjacent taxiway that ran parallel to the runway, according to a progress report from the National Transportation Safety Board.
On the taxiway were four planes waiting to take off: United Airlines flights 1, 863 and 1118, and Philippine Airlines Flight 115.
"Where's this guy going?" a United pilot asked.
At the last second, the Air Canada pilots advanced the plane’s thrusters when about 85 feet off the ground, to abandon their landing and circle the airport for a safe landing, according to investigators.
The Air Canada plane was as low as 59 feet off the ground at its lowest point, about 2.5 seconds after the pilots advanced the thrusters, according to the flight-data recorder.
Two of the United planes, Boeing 787 Dreamliners, have tails about 56 feet tall. The Philippine Airbus A340's tail is 55 feet tall.
Federal investigators haven’t come to any conclusions about what caused the near catastrophe, and their review could last another year. But if the planes had collided, it could have ranked among the worst aviation disasters in history.
The worst catastrophe involved a plane taking off. In March 1977 in the Canary Islands, two Boeing 747 aircraft collided while one tried to take off in thick fog, killing 583.
Missing from the Air Canada case will be a recording of the Air Canada pilots during the incident. The NTSB was notified about the incident July 9 and by then, the plane’s cockpit recording had already been overwritten.
In interviews after the incident, both pilots said that during their approach they believed they were lined up for Runway 28R. The pilots also told investigators they didn’t recall seeing aircraft on the taxiway, “that something did not look right to them,” according to the NTSB report.