Officials are investigating why a jet nearly landed on a taxiway holding four other planes instead of a runway at San Francisco International Airport.
US Federal Aviation Administration spokesman Ian Gregor said the pilot of the Air Canada Airbus A320 inadvertently lined up to land on Friday night on a taxiway that runs parallel to the runway.
An air traffic controller ordered the jet to pull up and circle for another approach, and it landed without further incident.
According to air traffic control audio posted online, a United pilot on the taxiway says the jet "flew directly over us."
Air Canada says it is also investigating the flight from Toronto, which had 135 passengers and five crew members.