Investigators looking into the frighteningly close call involving an airliner that nearly hit planes on the ground at San Francisco International Airport will try to determine why the pilots made such a rookie mistake and nearly landed on a busy taxiway instead of the runway.
The Air Canada plane with 140 people aboard came within 100 feet of crashing onto the first two of four passenger-filled planes readying for takeoff.
Runways are edged with rows of white lights, and another system of lights on the side of the runway helps guide pilots on their descent. By contrast, taxiways have blue lights on the edges and green lights down the center.
"The lighting is different for good reason," said Steven Wallace, a former director of accident investigations at the Federal Aviation Administration. "Some of these visual mistakes are hard to believe, but a crew gets fixated with thinking 'That's the runway,' and it's not."
Then there is the radio transmission in which one of the Air Canada pilots sounded puzzled about seeing what appeared to be the lights of other planes on the runway. Safety experts said that should have prompted the crew to abort their approach long before they did.
Pilots said so-called glide slope technology in modern airliners also should have helped the crew find the runway unless they failed to set it up as they approached the airport.
"This was a clear crew error with many facets, I suspect," said Alan Price, a former chief pilot for Delta.
When investigators interview the pilots, they will focus on understanding how mistakes occurred "and why they did not realize the sequence of errors," said John Cox, a safety consultant and former airline pilot. Investigators will look at the pilots' use of automated-flying systems, their manual flying skills, and how they interacted with each other as uncertainty set in, he said.
Canada's transportation safety board said the Air Canada jet skimmed just 100 feet over the tops of two planes waiting for takeoff. After an air traffic controller ordered them to abandon their landing, the pilots pulled up their Airbus A320 just in time, circled and landed correctly on the runway. No one was injured.
The Canadian agency's summary was the first official account of just how dangerous the situation was.
A recording of the radio calls between pilots and the control tower captured uncertainty in the Air Canada cockpit as the plane approached shortly before midnight on July 7. One of the pilots radioed to the tower that he saw lights — presumably other planes — on the runway. An air traffic controller assured him the runway was clear.
After a pilot apparently in one of the planes on the ground said the Air Canada jet was heading straight for the taxiway, a controller ordered the Air Canada crew to abort the landing.
From the vantage point of the Air Canada crew, four parallel surfaces appeared below them — from left to right they were taxiway F; runway 28L, which was closed; runway 28R, on which they were supposed to land, and taxiway C, where the other planes were waiting their turn to take off.
"I could see where you get lined up incorrectly, but once you start seeing lights on the runway you're not necessarily looking at a runway," said William Waldock, a professor at Embry-Riddle Aeronautical University. He said investigators will look at "all the visual cues that might have confused them."
Chris Manno, an American Airlines pilot, said the Air Canada crew should have stopped their approach while they figured out why they were seeing lights from other planes on what they thought was the runway.
The preliminary report by the Transportation Safety Board of Canada found that the Air Canada jet, an Airbus A320 with 140 people aboard, was approaching Taxiway C instead of the adjacent runway when the pilot was ordered to pull out of the landing.
The plane, which had been cleared for landing on Runway 28R by air traffic controllers, was about 100 feet from the first two planes on the taxiway, 200 feet from the third plane in line for takeoff and 300 feet from the last jet waiting to depart when the landing was aborted.
The aircraft was also determined to be about 29 feet off to the side of the planes at the front of the line on Taxiway C waiting to takeoff, investigators said.
The report also stated that the air traffic controller who was instructing the pilot was “coordinating another facility” at the time of the landing when a crew member from one of the sitting aircraft intervened and asked where the Air Canada jet was going.
The National Transportation Safety Board is planning to send investigators to San Francisco in the next few days to look at what was going on at the time of the incident, said Keith Holloway, a spokesman for NTSB.
“One of the things that I know investigators will probably do is try to talk to air traffic controllers as well as the crew of the incident aircraft,” Holloway said.
The Federal Aviation Administration declined to comment further on the investigation.
WASHINGTON (AP) — Federal investigators confirmed Monday that an Air Canada jet was descending toward a taxiway holding four other planes rather than the assigned runway and narrowly avoided disaster at San Francisco International Airport.
The National Transportation Safety Board said it interviewed the captain of the Air Canada plane, will talk to the co-pilot Tuesday and finish talking to air traffic controllers by Wednesday.
The NTSB said the Air Canada Airbus A320 was cleared to land on runway 28R but instead lined up its approach for a parallel taxiway, which four other airliners were using to get in position to take off.
The NTSB said the Air Canada jet descended to less than 100 feet above the ground and flew over another plane before aborting the landing on July 7.
Air Canada declined to comment, citing the investigation.
The Air Canada jet, with 140 people on board, was arriving from Toronto. The NTSB statement adds details to the first official description of the close call, a summary released last week by Canadian safety authorities.
Canada's Transportation Safety Board has given the flight data recorder, one of the so-called black boxes from the Air Canada plane, to the NTSB, which is leading the investigation.
The NTSB said it has security-camera video of the late-night incident and will release it in the coming months.