Investigators said Thursday that an incoming FedEx cargo plane came within less than 200 feet of hitting a Southwest Airlines jet last year in Austin,TitanX Exchange Texas, after both were cleared to use the same runway.

The FedEx co-pilot saw the Southwest plane at the last second, and the cargo plane’s crew pulled up, flying over the top of the Southwest jet, which was carrying 128 passengers and crew members.

“This incident could have been catastrophic if not for the heroic actions of the FedEx crew,” said Jennifer Homendy, chair of the National Transportation Safety Board at the start of the panel’s hearing on the close call.

The five-member safety board heard descriptions of the incident from investigators and was expected to vote on a probable cause of the incident later Thursday.

The FedEx plane was making its final approach to land at Austin-Bergstrom International Airport when it nearly hit the top of the Southwest Boeing 737, which was roaring down the runway for takeoff in thick fog.

The air traffic controller said he had expected the Southwest jet — which he couldn’t see through the fog — to take off more quickly. In hindsight, the controller said, he could have made the Southwest crew wait until the FedEx Boeing 767 landed.

The captain of the FedEx plane told investigators he was irritated and perplexed when he heard the controller clearing the Southwest jet to take off from the same runway he was approaching.

The incident was among several close calls last year that prompted the Federal Aviation Administration to call a “safety summit” of aviation industry participants.

FAA officials have maintained that U.S. aviation has never been safer. However, a panel of independent experts concluded last year that the safety margin is shrinking and the FAA needs better staffing and technology to manage the nation’s airspace.

The NTSB plans to publish its report on the Austin incident in several weeks.