NTSB data: Air Canada plane barely missed taxiing airliner

An Air Canada Airbus 320 attempting to land last month in San Francisco very narrowly avoided hitting another plane, data released Wednesday by the National Transportation Safety Board shows.

As it approached San Francisco International Airport to land on July 7, Air Canada Flight 759 mistakenly lined up with a taxiway where four planes were waiting, instead of a runway. The captain of the Airbus A320 aborted the landing. Air Canada did not immediately respond to a CNN request for comment.

At its lowest point, the Air Canada plane was 59 feet above the ground, the NTSB data says, barely higher than the height of the typical airliner's tail.

The Air Canada plane flew over the first plane, a Boeing 787, in the taxi queue. The second airliner on the taxiway -- an Airbus 340 -- had switched on its landing lights, apparently to make itself visible to the inbound jet.

As Flight 759 passed over the first airliner, the Air Canada crew used thrusters to get the plane to climb. At that point, it was just 85 feet above the ground. It dipped to 59 feet before climbing.

The pilots told NTSB investigators they thought they were lined up for runway 28R as they came in to land around midnight PDT. Runaway 28L was closed for construction and was unlit except for a 20-foot X on it. The Air Canada flight was instead headed for taxiway C, parallel to 28R.

The pilots said they didn't recall seeing any other planes, but they broke off the landing because something did not look right to them.

A few seconds after they started the process to climb, an air traffic controller told the Air Canada flight to go around.

The NTSB also said that during their approach, the Air Canada pilots flew too far right and caused the plane to disappear from radar for about 12 seconds, only reappearing as it passed over the 787.

The Air Canada captain has more than 20,000 flight hours and almost 4,800 as a captain of an Airbus 320. The first officer has 10,000 flight hours.

The Air Canada's cockpit voice recorder was overwritten, the NTSB said.

The NTSB is still investigating the incident and said this update contains no conclusions for what caused the near-miss.

Such incidents are incredibly rare, but can end in disaster. Runways and taxiways have specifically demarcated lighting to provide visual cues to pilots to avoid such incidents, but dangerous mix-ups do happen.

In 2009, a Delta Air Lines flight landed on a taxiway in Atlanta's Hartsfield-Jackson International Airport, and in 2015 an Alaska Airlines jet landed on one at Seattle-Tacoma International Airport. No one was hurt in either incident.

Runway incidents at takeoff and landing still account for the largest portion of aviation accidents.

Nearly 47% of fatalities occur during final approach and landing, according to an analysis of accidents from 2006 to 2015 by Boeing. The newest generation of aircraft now include moving airport maps on their displays to alert the pilot of the aircraft's position relative to a runway or a taxiway.

Companies like Honeywell Aerospace have also developed systems to advise pilots on the ground and in the air if they're approaching a taxiway or a runway, but such equipment is an optional feature on many aircraft.