Near mid-air collision over San Francisco

A China-bound passenger jet carrying 268 people nearly collided with a small plane shortly after taking off from San Francisco on the weekend, AFP reported today.

United Airlines flight 889, a Boeing 777-222, took off from San Francisco International Airport about 11.15am on Saturday.

The jet had climbed to an altitude of about 1,100 feet when a collision warning alarm sounded and pilots saw a small private plane turning hard, AFP reported.

The Boeing's traffic collision avoidance system "issued an 'ADJUST VERTICAL SPEED' alert, followed by a "DESCEND, DESCEND" alert," the National Transportation Safety Board said in a statement.

The pilots quickly levelled off the jet and saw the underside of the propeller-powered plane pass over them, with only 60-90 metres of separation between the two aircraft.