In what Federal Aviation Administration (FAA) officials say will probably rank in the most serious category of runway close calls, two airplanes came within 100 feet of colliding on a runway at Los Angeles International Airport (LAX) Saturday, September 30th, according to authorities.

A SkyWest regional jet with more than 30 passengers on board was about to take off from runway 25 Right at about 6 p.m. and had accelerated to 115 miles an hour, when a smaller Gulfstream business jet traveled onto the same runway.

The SkyWest pilot saw the Gulfstream jet and immediately slammed on the brakes, stopping only about 100 feet short of the business jet, FAA spokesman Ian Gregor said.

No one was injured in the incident, which Gregor said appears to be the most serious near-collision at LAX in six years.

Mike Foote, a National Air Traffic Controllers Association spokesman, said the controllers who witnessed the incident described it as the closest they had ever seen two planes come to colliding.

If it hadn’t been for the SkyWest pilot, who quickly put on the brakes when he did, the two planes would have most likely crashed, Foote said.

“It was as close as it possibly could’ve been,” Foote said of the near-collision. “(The SkyWest pilot) did a hell of a job.”

The eight-passenger Gulfstream jet, which was taxiing to another runway for takeoff, had approached runway 25 Right when air traffic controllers instructed the pilot to “hold short” of the runway and to not cross, Gregor said.

The controllers repeated the instructions and the Gulfstream pilot twice read back the instructions to hold short but the pilot “crossed anyway,” Gregor said.

The business jet crossed into the runway as the SkyWest jet, bound for San Antonio, was accelerating for takeoff, forcing the regional jet pilot to immediately take action, he said.

The force on the SkyWest plane’s brakes caused them to become so hot that the plane had to wait 15 minutes for them to cool off, he said.

FAA officials have not yet classified the seriousness of the runway close call, but Gregor said it would most definitely be rated in either the “A” or “B” category.

An “A” designation is when a pilot “takes extreme action to narrowly avoid a collision” or the event results in a collision. A “B” incident is when there is “significant potential for collision.”

The last incident at LAX that received an “A” rating was in March 2000, Gregor said.

The airport has now experienced eight runway close calls this year, including a “B”-rated incident in July, when a plane had to pull up to avoid another plane on its runway.

But Gregor added that six of the close calls at LAX were classified as “D” ratings, where there is no potential for collision.

After the September 30th incident, the Gulfstream pilot reportedly told officials that he thought he was cleared by controllers to cross both runways, even though he earlier repeated the instructions to not cross, Gregor said.

While the air traffic controllers executed their job correctly during the incident, they are having more difficulty catching pilot mistakes because they have been understaffed and are working more hours, Foote said.

Gregor said all of the safety systems at the airport worked correctly during the near-collision.

An alarm that warns air traffic controllers of impending runway collisions sounded, and the controllers in the tower and the SkyWest pilot saw the business jet cross onto the runway, he said.

“All of the safety systems worked as they should but the [Gulfstream] pilot made a mistake,” Gregor said.

“You never want to see an incident like this occur, but the response that we saw is exactly what we want to see when this does happen.”