SAN FRANCISCO — Federal safety officials are investigating why an Air Canada jet nearly landed on a taxiway holding four other planes instead of a runway at San Francisco International Airport.
The pilot of the Airbus A320 with 140 people aboard had lined up to land Friday on a taxiway that runs parallel to the runway when an air traffic controller ordered the jet to pull up and circle for another approach. The plane touched down without further problems.
It wasn't immediately clear how close Air Canada Flight 759 from Toronto came to disaster. Federal Aviation Administration spokesman Ian Gregor only gave basic details, citing an ongoing investigation.
A United Airlines pilot on the taxiway says the jet "flew directly over us," according to archived air traffic control audio posted on liveatc.net.
That pilot's plane was waiting for clearance to take off with three others on a taxiway — the aviation equivalent of side roads that planes use to move between runways and terminals. They do not have the same distinctive markings that appear on runways.
The incident, which Air Canada says it also is investigating, was first reported by the Bay Area News Group on Monday.
Safety experts said it is rare for planes to land on a taxiway instead of a runway, and when it happens it usually involves small planes at smaller airports.
Earlier this year, actor Harrison Ford flew over an airliner and landed his small plane on a taxiway in Southern California. The FAA did not sanction Ford.
In December 2015, an Alaska Airlines Boeing 737 landed on a central taxiway at Seattle-Tacoma International Airport. No one was injured.
Aviation-safety consultant Todd Curtis called the incident "definitely a serious event since a landing on an active taxiway could lead to a catastrophic accident."
Curtis said it was impossible to know how often commercial pilots line up their landing for a taxiway instead of a runway because government databases only capture that if there is an accident or serious incident. Many instances could go unreported, and many times they involve smaller planes at smaller airports, he said.
"They are much less common at large airports like SFO," Curtis said.
A spokesman for San Francisco's airport declined to comment.