Federal investigators on Thursday detailed a series of problems and failures that led to last month’s fatal collision between a regional jet and a fire truck at New York’s LaGuardia Airport.
According to A Preliminary report From the National Transportation Safety Board, the truck ran through the airport’s version of a stop light and the vehicle lacked a transponder, which hampered the collision warning system. There was also very heavy air traffic and an emergency involving another aircraft at the time.
Air Canada Express Flight 8646, a regional jet from Montreal with 76 people on board, collided with a fire engine seconds after landing on March 22. Pilots Antoine ForestA 30-year-old man and Mackenzie Gunter, 24, were killed, and 39 people were taken to hospitals with injuries, including the two people in the fire engine.
It was the first fatal accident at LaGuardia in 34 years. Here are some key points from the NTSB report.
Two air traffic controllers were on duty the night of the accident, consistent with the normal schedule.
But LaGuardia Airport was busier than usual because flight delays led to more than double the number of arrivals and departures after 10 p.m., according to aviation analytics firm Cirium.
The planes were landing every few minutes in the period leading up to the accident. At the same time, controllers had to change their duties due to an emergency involving a strong odor on a departing United Airlines plane. The fire truck involved in the accident was leading a convoy of emergency response vehicles.
While the senior controller coordinated the United emergency response, the other controller directed the vehicles on the ground while maintaining authorized takeoffs and landings.
“These controllers were very busy, very busy,” aviation safety expert Jeff Guzzetti said.
LaGuardia Airport is one of 35 major U.S. airports with an advanced surface surveillance system that combines radar data with information from transponders inside aircraft and ground vehicles to help prevent collisions. The consoles have a display in the tower that is supposed to display the location of each aircraft and vehicle.
The fire engine involved in the incident — and others in the convoy — were not equipped with transponders that would enable the system, known as ASDE-X, to accurately track their movements.
The system’s radar had difficulty distinguishing between a fire truck and other vehicles, and radar targets were intermittently integrated on the screen. As a result, no alarm was issued to alert the controllers.
According to an air traffic control broadcast, the Air Canada flight was cleared to land at 11:35 p.m. and about two minutes later, 25 seconds before the plane crashed, the fire crew requested to cross the same runway.
The flight was about 100 feet (30 m) above the ground when the air traffic controller allowed the fire truck to cross. At the time, the red light system on the runway that served as a warning to crossing traffic was still on.
It remained lit until the truck reached the edge of the runway, about three seconds before impact. By design, the lights go out two or three seconds before the plane reaches the runway intersection, the report said.
The truck should never have entered the runway while the warning lights were on, although the controller allowed it to cross, according to former airline pilot John Cox, chief executive of Safety Operations Systems.
“This is an automated system, so even though the controller says you’re cleared to cross, the lights mean there’s a plane either on the runway or about to arrive,” Cox said.
Guzzetti said it may have been difficult to see the runway lights before the accident because it was dark and the pavement was wet.
Nine seconds before the crash, the controller realized the plane and truck were about to collide and told the fire crew: “Whoa, whoa, whoa, whoa. Truck 1. Whoa, whoa, whoa, whoa.”
The fire truck tower operator told investigators he remembered hearing the phrase “Whoa, whoa, whoa” but did not know whose words were intended until he later heard “Truck 1.”
Then he noticed that the truck had already entered the runway. As they turned left, he said he could see the plane’s lights on the runway.
Cox said it was understood the driver did not realize the controller’s initial stop call was specific to the truck, because he was giving instructions to several different vehicles in succession.
“We now know who he’s talking to, but the first three whoa, whoa, whoa, there’s ambiguity, if you’re listening to him, who he’s talking to,” Cox said.
But Cox said he wasn’t sure the truck would have been able to stop in time even if the driver had hit the brakes at the first call to stop, because the NTSB said it reached 29 mph (47 km/h) before entering the runway.
Given the truck’s speed and weight, the vehicle “wouldn’t stop on a dime,” Cox said.