It was indeed a very close call, and both the Federal Aviation Administration (FAA) and the National Transportation Safety Board (NTSB) are investigating. Ultimately, it took the air traffic controller and the pilots of both those planes to spring into action to avoid a deadly mid-air collision.
The frightening moments in the skies over the San Francisco Airport begins shortly after the takeoff of the United Airlines jumbo jet. Flight 889 is bound for China with 268 passengers and crew. The pilot acknowledges a routine clearance for takeoff:
United Pilot: “Cleared for take off. United, um, triple 889.”
But as the United jet is climbing through 1,100 feet, the airport controller, who is also in contact with the pilot of the small Cessna, realizes the planes are too close and closing. He tells the Cessna pilot to go behind the United plane.
Controller: “7-echo maintain zero separation… pass behind that aircraft.”
Cessna Pilot: “7-0 will pass behind him.”
And he has orders for the United crew as well.
Controller: “889 – start heading to your right, maintain visible separation.”
Michael Barr of the USC Aviation Safety & Security Program said, “The light airplane turned away from the United Airline. That’s how the captain saw the underside of that airplane, so it was pretty darn close.”
So close, in fact, the planes are just 300 feet apart vertically and 1,500 feet apart horizontally. In the cockpit of the United jet, a collision avoidance alarm sounds, warning the pilots to descend to avoid a mid-air crash. It is called a TCAS alert. The United crew, as it noses the plane down, is clearly not happy.
United Pilot: “Okay, that set off that TCAS… that was… we need to talk.”
And, in fact, it was United Airlines that asked the NTSB to investigate this incident. The close call occurred on Saturday morning, but we are just learning about it at this time. And at this very early stage, it appears it may have been an error by the air traffic controller that put those planes too close.