NTSB report on the latest LAX runway incursion

You may have seen some news reports about the most recent runway incursion at LAX. The incident happened on August, 16, 2007, and involved aircraft operated by WestJet and Northwest Airlines. No one was injured, but it certainly was a close call. After a preliminary investigation, the National Transportation Safety Board (NTSB) estimates that the two aircraft may have missed each other by less than 40 feet.

Here is a description of what happened, drawn from the NTSB's preliminary incident report:

On August 16, 2007, at approximately 12:57 Pacific daylight time, a runway incursion occurred involving West Jet (WJA) 900, B737 and Northwest Airlines (NWA) flight 180, an A320, at Los Angeles International Airport, Los Angeles, California.

WJA900 landed on runway 24R and exited at taxiway Y then changed to ground control frequency without authorization while the airplane was holding between the parallel runways.

The tower controller cleared NWA180 for takeoff from runway 24L. Meanwhile, the pilot of WJA900 contracted ground control and said, "Ground, WJA900 with you on reverse [taxiway] yankee for gate 35." The ground controller assumed that the tower controller had instructed the flight to cross runway 24L and responded, "WJA900, Los Angeles tower, taxi [via taxiway] echo to the gate."

Ten seconds later, the pilot of WJA900 confirmed that the flight was cleared to cross runway 24L. The ground controller asked who called and the pilot again asked whether or not they were cleared to cross the runway. The ground controller then realized that WJA900 had not been instructed to cross runway 24L and told WJA900 to stop.

According to the FAA and WJA, the airplane crossed the hold short line but did not enter the runway.

According to the FAA, the two aircraft missed colliding by 37 feet (wingtip of A320 to the nose of the B737) as NWA180 departed runway 24L. [NTSB Report No. OPS07IA009A]

The NTSB notes that the Airport Movement Area Safety System (AMASS) at LAX was operational at the time of the incident, but it is unknown whether or not it activated.