2,300 Feet: The JFK Runway Incursion Between American 106 and Delta 1943

An American Airlines 777 crossed an active JFK runway without clearance while a Delta 737 was in its takeoff roll on that same runway — and the only reason 298 people didn't end up in a runway collision was a surface-radar alert and a Delta crew that rejected the takeoff at 105 knots, roughly 2,300 feet short of where the two aircraft's paths crossed.

A Missed Turn Becomes a Runway Crossing

American Airlines Flight 106, a Boeing 777-200 taxiing out for a flight to London Heathrow, was instructed to turn onto Taxiway K. Instead, the crew continued straight on Taxiway B, then turned onto Taxiway J — a routing that put the aircraft on a path to cross Runway 4L. They crossed it without ATC clearance to do so.

A Runway That Wasn't Clear

Runway 4L was not free at that moment. Delta Air Lines Flight 1943, a 737-900ER bound for Santo Domingo, had just begun its takeoff roll on that same runway. Two widebody and narrowbody jets, one taxiing across a runway without clearance and one accelerating down it for takeoff, were now converging.

The Save

JFK tower's ASDE-X surface detection system — radar built specifically to catch exactly this kind of conflict — alerted the controller to what was developing. The controller canceled Delta 1943's takeoff clearance. The Delta crew rejected the takeoff immediately, a maneuver that gets progressively more demanding on the airframe and brakes the faster the aircraft is going; they were at approximately 105 knots when they did it, and the aircraft stopped about 2,300 feet short of the runway intersection where American 106 was crossing. American 106 continued across; Delta exited the runway safely afterward. None of the 298 people aboard either aircraft were hurt, and neither aircraft was damaged.

What the Investigation Found

The NTSB placed the primary cause on the American crew: a surface-navigation error rooted in distraction from performing multiple cockpit tasks at once during taxi, which cost them situational awareness of where they actually were relative to their cleared route. But the board's finding didn't stop there. It also cited the tower team's failure to catch the deviation before ASDE-X did, the runway status light system activating too late to stop the crew from crossing the hold-short line in the first place, and American Airlines' own lack of procedural safeguards against exactly this kind of concurrent-task distraction during taxi. The same finding credited the ASDE-X alert and the controller's fast reaction — canceling Delta's clearance the moment the conflict was detected — with reducing the severity of the incursion and likely preventing a collision outright.

This reconstruction was researched from official investigation records where they exist, the original air traffic control recording, and contemporary reporting. The aircraft movement, timeline and written account were assembled independently by Flight Follower. Where an investigation is open or no probable cause has been published, the account says so rather than offering one.

Timeline

Sources and investigation material

• https://www.ntsb.gov/investigations/Pages/DCA23LA125.aspx

Accident Facts

Sources

• NTSB docket DCA23LA125 (probable cause quoted verbatim)