The terrifying moment an Air Canada jet nearly landed on four passenger planes on Friday has been captured in audio.
Pilots and the control tower at San Francisco International Airport (SFO) can be heard remarking in astonishment as the AC759 narrowly misses them on the packed taxiway.
The dramatic moment, which could have claimed more than 1000 lives, was very nearly a history-making catastrophe, the Daily Mail reports.
"If it is true, what happened probably came close to the greatest aviation disaster in history," retired United Airlines Captain Ross Aimer, CEO of Aero Consulting Experts told the Mercury News.
The near-miss occurred at 11:56pm on Friday, as the Air Canada jet - an Airbus A320 that can carry up to 220 people - was coming into land at SFO.
Typically, incoming international planes air directed to runways 28L or 28R, referred to verbally as "28-Left" or "28-Right".
In the audio, the Air Canada pilot can be heard asking SFO control if he's heading towards the right runway.
"Tower control, I just want to confirm that - this is Air Canada 759, I can see some lights on the runway there, across the runway, can you confirm we're good to land?"
"Canada 759, confirmed to land on runway 28-Right, there is no one on 28-Right but you."
But what the tower doesn't know is that the pilot isn't lined up for runway 28R at all.
Instead, he's heading for Taxiway C, which lies parallel to it, and on which four passenger planes were waiting to get into position for takeoff.
As the Air Canada jet thanks airport control, another pilot, audibly agitated buzzes in: "Where is this guy going? He's on the taxiway!"
Tower quickly tells the plane to "go around" and it peels off, narrowly avoiding a massive collision.
"Air Canada flew directly over us," another pilot says.
"Yeah, I saw that guys," replies the tower.
Captain Aimer said that if the tower hadn't been able to swiftly redirect the Air Canada plane, disaster would have followed.
"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," he remarked.
It's not yet known what types of planes were on the taxiway, but "wide body" planes are the large, two-aisle planes capable of transporting hundreds of people internationally.
Wide bodies can carry between 200 and 480 passengers, plus crew.
Even if the other planes were at the lower end of the scale, and only half full, a collision could well have killed several hundred people.
Aimer added that the near-miss had become the talk of pilots everywhere.
"This is pretty huge," he said. "My buddies called and asked if I knew about it. They're a sitting duck on the taxiway. They can't go anywhere."
It is not known if any action has been taken against the pilot; Air Canada has been contacted for comment.
San Francisco International Airport has also been contacted.
The FAA have launched an investigation, as has Air Canada.
History's worst aviation disasters
At present it's unclear how many people were on the planes involved in Friday's near-miss.
However, all planes were reportedly wide-bodies - or jumbo jets - that could contain hundreds of people each. The Air Canada plane was capable of holding as many as 220 passengers, plus crew.
Had all five planes had just 150 passengers each, the total would have eclipsed the worst disasters to date - the details of which follow.
Tenerife, Spain, 1977: 583 people killed
While trying to take off from Los Rodeos Airport in dense fog without clearance from air traffic control, a KLM Boeing 747 collided with a taxiing Pan Am 747.
The resulting crash spilled jet fuel onto the runway, which then ignited in a fireball that could not be put out for several hours.
Everyone aboard the KLM flight was killed; 61 of the 396 passengers on the Pan Am flight survived.
Ueno, Japan, 1985: 520 people killed
A Japan Airlines Boeing 747SR explosively decompressed when its bulkhead gave way while the plane was at cruising altitude - at 33,000ft.
It then crashed into Mt Takamagahara in Ueno, Gunma Prefecture, about 100km from Tokyo.
It remains the worst single-aircraft disaster in history - though, extraordinarily, four people survived and were found in the wreckage.
An investigation later revealed that the plane had been involved in a collision at an airport seven years earlier and not repaired to Boeing standard, leaving its bulkhead compromised and liable to rupture.
Charkhi Dadri, India, 1996: 349 people killed
The world's deadliest mid-air collision happened when the pilot of Kazakhstan Airlines Flight 1907 flew lower than he had clearance for.
Just before the collision, the Kazakh plane attempted to ascend, causing its tail to clip that of Saudia Flight 763, severing both tails.
All passengers and crew aboard both planes died.