12-second runway near-miss revealed
- A newly resurfaced National Transportation Safety Board finding detailed a Los Angeles runway incursion in which Asiana Flight 204 overflew Southwest Flight 440 after a relief controller cleared both aircraft onto runway 24L. - The controller realized the conflict only after an Airport Movement Area Safety System alarm, when the Asiana Boeing 747 was about 12 seconds from impact and the Southwest 737 had just entered the runway. - The case remains a reference point in U.S. runway-safety debates over controller workload, handoff errors and surface-alert technology gaps. (ntsb.gov)
A Los Angeles runway incursion left an arriving Asiana Boeing 747 about 12 seconds from colliding with a Southwest 737 after both were cleared for runway 24L. (ntsb.gov) The National Transportation Safety Board report says the incident happened at Los Angeles International Airport on August 19, 2004, during a controller relief change at the local-control position. (ntsb.gov) The outgoing controller had already cleared Asiana Flight 204 to land on 24L. About two minutes later, the relief controller told Southwest Flight 440 to taxi into position and hold on that same runway. (ntsb.gov 1) (ntsb.gov 2) Twelve seconds after that, the relief controller cleared Southwest for takeoff. Radar data showed the Asiana 747 was 1.26 miles from the runway and about 35 seconds from the threshold. (ntsb.gov) That timing meant the Southwest crew had less than 35 seconds to enter runway 24L, start the takeoff roll and cover 6,000 feet before the 747 arrived. The NTSB said that was impossible. (ntsb.gov) The Southwest captain said he saw the Asiana jet on final approach but believed it was landing on parallel runway 24R. The relief controller later said he also believed the Asiana flight was landing on 24R, not 24L. (ntsb.gov) The controller became aware of the conflict only when the Airport Movement Area Safety System, a surface-alert system that warns of runway conflicts, generated an alarm. By then, the NTSB said, the Asiana jet was about 12 seconds from colliding with Southwest. (ntsb.gov) The Asiana crew initiated a go-around and passed about 200 feet over the Southwest jet. The NTSB said a collision would likely have occurred without the Asiana pilots’ prompt action. (ntsb.gov) The case still sits inside a broader runway-safety push. The NTSB says avoiding runway collisions often comes down to “just a few seconds” and has called for direct cockpit alerts and clearer runway-crossing protections. (ntsb.gov) More recent NTSB investigations have reached similar conclusions. In Austin in 2023, a Southwest departure and a FedEx arrival came within about 150 to 170 feet after a controller assumption and the lack of surface-detection equipment. (ntsb.gov 1) (ntsb.gov 2) In New York in 2023, an American Airlines Boeing 777 crossed JFK runway 4L without clearance, forcing a Delta 737 to reject its takeoff after an ASDE-X alert. The NTSB blamed crew distraction, concurrent tasks and late runway-status lights. (ntsb.gov 1) (ntsb.gov 2) The Los Angeles incident is old, but the clock in it is modern: one mistaken mental picture, one late alarm, and 12 seconds left to stop a runway collision. (ntsb.gov)
