U.S. safety officials said on July 13 that they were investigating a runway incident in Florida that week in which two jetliners -- one landing and another that wandered into its path -- missed each other by less than 100 feet (30 metres).

The U.S. National Transportation Safety Board said the near collision at Fort Lauderdale-Hollywood Airport on July 11 involved an Airbus A320 operated by United Airlines and a Delta Air Lines' Boeing 757.

According to a preliminary safety board report, United Flight 1544 heading to Dulles International Airport near Washington, D.C., was given taxi clearance for an afternoon takeoff and told to stop short of Runway 9L.

But an air controller noticed the jet was going too fast to stop, with Delta Flight 1489 from Atlanta bearing down.

"UAL 1544 stop, stop, stop," the controller called into the radio.

But the United plane with 138 people aboard continued to roll before stopping 30 feet short of the runway's center line.

Controllers had instructed the inbound Delta flight with 167 aboard to go around. But the plane's main landing gear had touched the ground on 9L, the safety board said.

With the Delta plane's back wheels down and its nose still elevated, it would have been difficult for the pilots to see immediately down the tarmac, investigators believe. However, the crew "noted the urgency in the controller's voice" and managed to get the jet back in the air, the safety board said.

The U.S. Federal Aviation Administration said the Delta plane then cleared the United aircraft by less than 100 feet.

According to the FAA, the United crew said they had missed a turn that would have put them on another taxiway where they were to wait before takeoff.

A United spokeswoman said the carrier was reviewing the matter with investigators.

Officials at Delta referred additional questions about the incident to the FAA.

The Delta plane landed safely and no one was hurt. The United flight took off and completed its flight to Washington without incident.

Unlike some bigger U.S. airports, Fort Lauderdale is not equipped with a radar system to monitor aircraft and other traffic on the ground.

Skies were partly cloudy at the time, officials said.