Controllers in Fort Lauderdale said it was the closest call they had ever seen, reports CBS News correspondent Nancy Cordes.
Air traffic controllers noticed a plane entering a runway Wednesday as Delta Flight 1489 approached the same runway for a landing, Federal Aviation Administration spokeswoman Kathleen Bergen said.
The controllers alerted the Delta crew to pull up and circle the airport to avoid United Flight 1544, which had missed a turn onto another taxiway, Bergen said.
Controllers estimate the Delta crew missed the United plane by less than 30 feet – close enough to hit the jet's tail, had the plane not rolled to a stop, reports Cordes.
Investigators were focusing on what caused the United flight to veer into Delta's right of way, Bergen said.
The United flight went on to its destination at Washington's Dulles Airport with 133 passengers on board, said Megan McCarthy, spokeswoman for Chicago-based UAL Corp.'s United Airlines. She declined further comment.
The Delta flight was arriving from Atlanta with 167 passengers, said Betsy Talton, a spokeswoman for Atlanta-based Delta Air Lines Inc. She declined further comment.
The near-miss, or "runway incursion" in FAA terminology, is under investigation, Bergen said.
The Fort Lauderdale-Hollywood airport had three runway incursions during the 12 months that ended May 31, according to FAA records. Two were blamed on pilot error and the third was ruled an air traffic control error. Nationwide, the FAA reported 330 runway incursions in fiscal year 2006.
One of the worst runway incursions was in 1991, when a US Air jet was mistakenly allowed to land on a Los Angeles runway while a twin-engine turbo-prop plane was taking off, killing thirty-four people, reports Cordes.
Meanwhile, a federal reportof covering up mistakes by air traffic controllers at one of the nation's busiest airports and sometimes shifting the blame to pilots.
The problems at Dallas-Fort Worth International Airport included planes that flew too close together and a controller who did not notify a colleague when a plane was cleared for takeoff.
The allegations came from the U.S. Office of Special Counsel, an independent investigative agency responsible for protecting government whistle-blowers. The office's report renewed accusations that were made in 2005 but, according to the investigator, never fixed.