A terrifying near miss Friday involving an Air Canada pilot apparently unfamiliar with the runways at SFO could have led to the "greatest aviation disaster in history" according to one aviation expert contacted by the Mercury News. Mistaking the airport's Taxiway C — which had four full wide-body aircraft on it waiting to take off — for runway 28R, the pilot can be heard asking air traffic control to confirm that he's cleared to land. They confirm that there is no one on the runway, but as the Air Canada flight is making the approach an unknown voice, possibly that of one of the pilots on the taxiway, says, "Where is this guy going? He’s on the taxiway!"

Immediately, as transcripts obtained by CBS 5 show, air traffic control tells the Air Canada pilot to "go around" — a rare move in which the pilot is told to pull up out of the descent and circle back around to land. The air traffic controller says, "Air Canada looks like you were lined up for Charlie there," referring to Taxiway C. (See a map of the runways here.)

You then hear one of the other pilots on the taxiway, a United pilot, say, "United One, Air Canada just flew directly over us."

This all happened around 11:45 p.m. Friday night.

The main SFO runways are lined with very bright lights, including some new LEDs, while the taxiway in question, as ABC 7 notes, is lined with dim lights.

As the Mercury News reports, "the apparent pilot error already has the aviation industry buzzing" given the implications of the mistake. Retired United Airlines Capt. Ross Aimer, who is the CEO of Aero Consulting Experts, tells the paper he's already gotten numerous calls and messages from pilot friends about it, saying "what happened probably came close to the greatest aviation disaster in history," given the fact that a crash was narrowly avoided that would have involved not just five planes full of people, but four planes full of fuel on that taxiway. Referring to pilot friends who witnessed the incident, he says, "They're a sitting duck on the taxiway. They can't go anywhere."

The FAA is investigating, and has already noted that fog was not to blame — it was a clear night, and the pilot was landing the plane manually.

Via ABC 7 we get the following statement issued Monday by Air Canada: "Air Canada flight AC759 from Toronto was preparing to land at SFO Friday night when the aircraft initiated a go-around. The aircraft landed normally without incident. We are still investigating the circumstances."

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