The U.S. Federal Aviation Administration is investigating what could have been a disastrous incident for an Air Canada plane landing in San Francisco.
The flight nearly landed on a taxiway, just before midnight Friday, where four other planes were waiting to take off.
According to the FAA, Air Canada flight 759 was cleared to land on a runway but the pilot inadvertently lined up for a taxiway which runs parallel to the runway.
In air traffic control audio, the pilot appears confused. He says he sees lights and asks control whether he is clear to land on the runway. He's told he is.
Another voice can then be heard saying, "Where's this guy going? He's on the taxiway."
The pilot was told to circle around and try again before landing safely.
One aviation expert told the San Jose Mercury News the incident, if true, "probably came close to the greatest aviation disaster in history."
Retired United Airlines Capt. Ross Aimer, CEO of Aero Consulting Experts, told the paper, "If you could imagine an Airbus colliding with four passenger aircraft wide bodies, full of fuel and passengers, then you can imagine how horrific this could have been.”
Air Canada says it is also investigating the incident.