Incident Overview
On August 16, 2007, at approximately 1257 Pacific daylight time, a runway incursion occurred at Los Angeles International Airport in Los Angeles, California, involving WestJet (WJA) flight 900, a Boeing 737, and Northwest Airlines (NWA) flight 180, an Airbus A320.
Sequence of Events
WJA900 landed on runway 24R and exited at taxiway Y. The flight then changed to ground control frequency without authorization while holding between the parallel runways. The tower controller cleared NWA180 for takeoff from runway 24L.
Meanwhile, the pilot of WJA900 contacted ground control, stating, "Ground, WJA900 with you on reverse [taxiway] yankee for gate 35." The ground controller believed that the tower controller had instructed WJA900 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 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.
Aftermath
According to the FAA and WestJet, 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, measured from the wingtip of the A320 to the nose of the B737, as NWA180 departed runway 24L. The Airport Movement Area Safety System (AMASS) activated on this incident.