By David Shepardson
(Reuters) -The Federal Aviation Administration and the U.S. National Transportation Safety Board are investigating an aborted landing in Austin, Texas, on Saturday morning by a FedEx cargo plane that had been set to land on a runway on which a Southwest Airlines jet was also cleared to depart from, the agencies said.
The two planes came close to colliding in an extremely serious safety incident, two sources briefed on the matter told Reuters. The incident occurred in poor visibility conditions in Austin.
"Shortly before the FedEx aircraft was due to land, the controller cleared Southwest Flight 708 to depart from the same runway," the Federal Aviation Administration (FAA) said.
The NTSB separately said it was investigating "a possible runway incursion and overflight involving airplanes from Southwest Airlines and FedEx."
The FAA said FedEx Flight 1432, a Boeing 767 cargo plane, which had departed from Memphis, was cleared to land on Runway 18-Left around 6:40 a.m. while the aircraft was several miles from the airport. The Southwest plane had not yet departed when the FedEx was nearing the runway.
"The pilot of the FedEx airplane discontinued the landing and initiated a climb out," the FAA said.
It was not clear precisely how close the two airplanes came to colliding.
The Cancun, Mexico-bound Southwest flight, a Boeing 737-700, safely departed and landed at 9:47 a.m. ET.
Southwest declined to comment. FedEx did not immediately respond to a request for comment.
(Reporting by David Shepardson; Editing by Sandra Maler and Leslie Adler)