NEW YORK (AP) — A firefighter whose truck collided with an Air Canada Express jet last month on a runway at New York's LaGuardia Airport, killing both pilots, heard an air traffic controller warn “stop, stop, stop” but didn't know who it was for, federal investigators said Thursday.

Just seconds earlier, the controller had cleared the fire truck to cross the runway, but the truck started moving while warning lights that act as a stop sign for crossing traffic were still lit, the National Transportation Safety Board said in a preliminary report on the March 22 crash.

Because the truck lacked a transponder, a crash prevention system in the control tower was unable to reliably determine its position, “did not predict a potential conflict” with the plane and did not generate an audio or visual alert, the report said, pointing to a series of failures that contributed to the crash.

“There were so many opportunities where this accident could have been prevented,” aviation safety expert Jeff Guzzetti said after reviewing the report.

In addition to the control tower and truck driver, he said the report suggests the pilots had a chance to recognize the danger and pull up. But, he said, they may have been too dialed into landing.

After the air traffic controller's initial stop warning, the fire truck's turret operator heard the controller say, “Truck 1, stop, stop, stop,” and realized he was telling the truck to halt, the report said. By then, the truck was already on the runway as Air Canada Express Flight 8646 was landing and speeding toward it.

The turret operator, one of two crew members in the fire truck, recalled to investigators that as the vehicle turned left, he saw the airplane’s lights on the runway, the report said. The plane registered a speed of 104 mph (167 kph) just before the collision. The truck was going about 30 mph (48 kph).

The fire truck was leading a convoy of vehicles, including four fire trucks, a police car and a stair truck, responding to an emergency involving a strong odor that was making flight attendants feel ill aboard a departing United Airlines jet.

The air traffic controller cleared the truck to cross the runway just 12 seconds before the plane touched down, investigators said. About eight seconds later, the controller frantically began calling for the truck to stop.

Pilots killed, 39 people hurt, including fire crew members

Source: WPLG