The National Transportation Safety Board (NTSB) issued an investigation update on Wednesday, detailing that Air Canada Flight 759, a 190-seat Airbus 320, came within 59 feet of the ground at one point. Had it descended for just a few more seconds, it would have collided with four other taxiing planes and likely killed or injured thousands.
The Air Canada plane began a descent to land at SFO, but for reasons that are still unclear the pilot descended on the taxiway (instead of the runway he was cleared for). On the taxiway were four planes waiting to take off: United Airlines flights 1, 863 and 1118 (two of which were Boeing 787 Dreamliners that can seat between 242 and 335 passengers depending on variant), and Philippine Airlines Flight 115 (a 375-seat Airbus A340).
The Philippine Airlines jet switched on its emergency lights, alerting air traffic control that something was wrong. By the time the message got across and Flight 759 became aware that it was about to crash, it was 85 feet off the ground.
The pilot activated the plane's thrusters and hastily abandoned the landing. The plane continued to descend for a couple of seconds and reached a low of 59 feet before beginning its ascent and averting disaster.
Federal Aviation Administration (FAA) and NTSB investigators are in the midst of looking into the incident, but the review process could last until mid-2018. One major obstacle in the path of the investigation is that the Air Canada plane's cockpit recordings were overwritten, as NTSB's investigation didn't begin until two days after the incident.
During interviews, both pilots claimed to believe they were lined up for a landing on the runway during the approach, and they didn't see the taxiway aircraft underneath them. Both pilots were veterans, with more than 30,000 hours of flying time between them.
Air Canada declined to comment on the incident, citing the ongoing investigation.
Forty-seven percent of all aviation fatalities occur during final approach and landing, according to an analysis of aviation accidents between 2006 and 2015 by Boeing.