A FedEx aircraft aborted landing to avoid a Southwest Airlines passenger jet that was mistakenly cleared for the same runway

• A FedEx aircraft aborted its landing to avoid a Southwest Airlines jet on Saturday during heavy fog.
• Both were mistakenly cleared for the same runway at Austin Bergstrom International Airport.

A FedEx aircraft had to abort a landing in heavy fog to avoid colliding with a Southwest Airlines passenger jet on the same runway.

The crew operating FedEx's Boeing 767 had to execute a "climb out" in order to avoid landing on top of Southwest's Cancun-bound Boeing 737 at Austin Bergstrom International Airport shortly after 6 a.m. on Saturday.

It's being investigated by both the Federal Aviation Administration, or FAA, and the National Transportation Safety Board.

The FAA told Insider: "According to preliminary information, FedEx Flight 1432 was cleared to land on Runway 18-Left around 6:40 a.m. local time while the aircraft was several miles from the airport. Shortly before the FedEx aircraft was due to land, the controller cleared Southwest Flight 708 to depart from the same runway.

"The pilot of the FedEx airplane discontinued the landing and initiated a climb out," it added.

Footage posted to Twitter by flight-tracking website FlightRadar24 shows the near-overlapping flight paths of the two planes.

After aborting its landing, FedEx's aircraft circled the airport before successfully touching down at 6:51 am, according to data from FlightAware. Southwest's passenger jet departed safely and reached its final destination in Cancun, Mexico, per FlightRadar24.

In a statement posted on Twitter, the National Transportation Safety Board said it was "investigating a surface event at Austin-Bergstrom International Airport Saturday, a possible runway incursion and overflight involving airplanes from Southwest Airlines and FedEx."

In a statement to the Associated Press, the airport said it was "aware of the Federal Aviation Administration's investigation into the discontinued landing of a flight." It continued: "We will assist our FAA partners and their investigation as necessary."

A spokesperson for FedEx told Insider: "FedEx Express Flight 1432 from Memphis, Tenn. to Austin, Texas safely landed after encountering an event just before landing at Austin Bergstrom International Airport Saturday morning."

Southwest Airlines and Austin-Bergstrom International Airport did not immediately respond to requests for comment from Insider.

It comes shortly after a Delta Boeing 737 had to abort its takeoff after a American Airlines Boeing 77 passed in front of it on the runway at New York's JFK Airport.

The FAA said it was investigating the incident, which involved took place on January 13.

One passenger aboard the Delta aircraft told Insider the jet came to a very sudden halt two or three seconds after it began accelerating down the runway to take off, thrusting passengers forward in their seats.

"There were vocal reactions, a few screams when the plane first started slowing, then total silence. I felt a surge of adrenaline knowing this was not normal, and not knowing what to expect," he said.