Truck Cleared to Cross Runway 20 Seconds Before Impact

A critical piece of safety tech was missing from the fire truck struck by an Air Canada jet at LaGuardia Airport, federal investigators say. The National Transportation Safety Board on Tuesday said the Port Authority fire vehicle did not have a transponder, meaning it couldn't be seen by the surface tracking system that can help controllers monitor ground movements and generate alerts, per USA Today. Two pilots were killed and dozens of passengers and two firefighters were injured when the Air Canada Express CRJ-900 and the truck collided on Runway 4 late Sunday night.

NTSB Chair Jennifer Homendy said that even without the truck's transponder, the monitoring system, known as ASDE-X, also failed to generate an alert because of closely spaced emergency vehicles merging and separating near the runway, which prevented it from establishing a reliable track. The fire truck had been dispatched to check out a United Airlines plane that aborted takeoff after reporting an odor. One of two air traffic controllers on duty cleared it to cross Runway 4 just 12 seconds before the Air Canada jet touched down and 20 seconds before impact, per CTV News. Homendy said investigators have yet to speak with the firefighters, so it's unclear if they heard an order to stop, reportedly coming nine seconds before impact.