Key takeaways from a report into the deadly plane crash at LaGuardia Airport

Federal investigators detailed Thursday a series of problems and failures that led to last month’s deadly collision between a regional plane 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 stop light and the vehicle did not have a transponder, which interfered with 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 plane from Montreal with 76 people on board, hit the fire truck seconds after landing on March 22. Pilots Antoine Forest, 30, and Mackenzie Gunther, 24, were killed and 39 people were taken to hospital with injuries, including the two people on board the fire truck.

This is the first fatal accident at LaGuardia in 34 years. Here are some key points from the NTSB report.

Busy air traffic controllers

Two air traffic controllers were on duty the night of the accident, according to their normal schedule.

But LaGuardia was busier than usual as flight delays caused the number of arrivals and departures after 10 p.m. to more than double what was expected, according to aviation analytics firm Cirium.

Planes were landing every few minutes before the crash. At the same time, controllers had to modify their tasks due to an emergency related to a strong odor on a departing United Airlines plane. The fire truck involved in the collision was leading a convoy of vehicles responding to the emergency.

While the senior controller coordinated United’s emergency response, the other controller took over directing ground vehicles while continuing to authorize takeoffs and landings.

“These controllers were just very busy, just too busy,” said Jeff Guzzetti, an aviation safety expert.

No transponder on the fire truck

LaGuardia 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 controllers have a screen in the tower that is supposed to show the location of each plane and vehicle.

The fire truck involved in the crash — and other members of the convoy — were not equipped with transponders that would have allowed the system, known as ASDE-X, to accurately track their movements.

The system’s radar had difficulty distinguishing the fire truck from other vehicles, and radar targets intermittently merged on the screen. As a result, no alarm was triggered to alert the controllers.

The red lights were on

According to air traffic control transmissions, the Air Canada plane was cleared to land at 11:35 p.m. About two minutes later, 25 seconds before the accident, firefighters requested to cross the same runway.

The flight was about 30 meters above the ground when an air traffic controller cleared the fire truck to cross. At the time, a red light system on the runway serving as a warning to crossing traffic was still on.

They remained illuminated until the truck reached the edge of the track, approximately three seconds before the collision. By design, the lights turn off two or three seconds before a plane reaches a runway intersection, the report said.

The truck should never have entered the runway while the warning lights were on, even if the controller had cleared it to cross, according to former airline pilot John Cox, CEO of Safety Operating Systems.

“It’s an automated system, so even if the controller says you’re cleared to cross, the lights mean there’s an airplane that’s on the runway or about to be,” Cox said.

Guzzetti said it may have been difficult to see the runway lights before the crash because it was dark and the roadway was wet.

‘Stop, stop, stop’

Nine seconds before the accident, the controller realized the plane and truck were about to collide and told firefighters: “Stop, stop, stop, stop. Truck 1. Stop, stop, stop, stop.”

The fire truck’s turret operator told investigators he remembered hearing “stop, stop, stop” but didn’t know who the words were intended for until he next heard “Truck 1.”

He then noticed that the truck had already entered the track. As they turned left, he said he could see the plane’s lights on the runway.

It’s understandable that the driver didn’t realize the controller’s initial stop call was for the truck, Cox said, since he was giving instructions to several different vehicles in succession.

“Now we know who he’s talking to, but the first three stop, stop, stop are ambiguous, if you listened 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 braked suddenly at the first call to stop, because the NTSB said he reached 29 mph (47 kph) before entering the track.

Given the speed and weight of the truck, Cox said, the vehicle “is not going to stop on a dime.”