Audio reveals final three minutes inside cockpit of Air Canada flight as investigators hone in on overlapping errors that led to fatal collision

Audio obtained from the Air Canada cockpit recorder indicates overlapping errors at LaGuardia International Airport in the minutes before the plane crashed into a fire truck.

Among the significant errors revealed Tuesday was that an air traffic controller allowed Flight 8646 from Montreal to land on Runway 4, while another controller allowed a fire truck to continue on the same runway.

Cockpit voice recordings revealed that the truck’s surface safety system also failed to trigger alerts for controllers after the initial miscommunication occurred around 11.40pm on Sunday.

There were two air traffic controllers working in the tower at night: a local controller and a controller in charge. One of them was also serving as ground controller.

Controllers had to plead for the fire truck to stop seconds before it crashed into a Bombardier CRJ-900 traveling down the runway at 150 mph.

Due to the impact, both pilots on the plane died and 41 people were injured.

“We rarely investigate a major accident that results in a single failure,” said NTSB chair Jennifer Homendy. Wall StreetJournal.

‘Our aviation system is incredibly safe because there are so many layers of defense built in to prevent an accident. So when something goes wrong, it means a lot of things have gone wrong.’

National Transportation Safety Board investigators are currently working to determine what caused the fatal crash and are focusing on possible problems with both the air traffic control tower and the fire truck at the scene.

National Transportation Safety Board investigators are also looking into the possibility that the fire truck (pictured) did not have a working transponder.

But data from the cockpit recorder shows Air Canada Flight 8646’s descent to LaGuardia airport began normally, according to senior aviation investigator Doug Brazy.

In the first two minutes and four seconds before impact, the pilots followed procedure and radioed air traffic control for permission to land.

An air traffic controller later stated that the flight was cleared to land on Runway 4, which would be second in line to land on the runway.

Approximately 30 seconds later, Air Canada’s flight crew lowered the aircraft’s landing gear, adjusted the wing flaps for final descent, and confirmed that the landing checklist had been completed.

Two Port Authority firefighters responding to reports of a ‘bad smell’ on another plane radioed the tower themselves about a minute before the collision.

But the transmission had been ‘stepped down’; This meant that while the fire truck was radioing the tower, either a microphone was turned on or someone else was communicating on the same frequency and the transmission was interrupted.

“This is important because it could mean that someone might not be able to hear the other part of the communication,” Homendy said at a news conference Tuesday.

Meanwhile, the Air Canada flight continued to descend and one of the pilots reported to air traffic control that the aircraft had reached 500 ft above the ground and was on a steady approach.

Just 14 seconds later, the controller asked which vehicle should cross the track, officials said.

Someone from inside the fire truck intervened and the air traffic controller was heard directing the emergency vehicle to ‘pass Runway 4 at the taxiway delta’.

Senior Aviation Accident Investigator Doug Brazy reveals the timeline for the final landing of an Air Canada flight Sunday night

It remains unclear whether it was the same air traffic controller who gave permission for both the Air Canada plane and the fire truck to take to the runway. LaGuardia’s air traffic control tower pictured in 2011

Almost simultaneously, inside the Air Canada cockpit, an advanced ground proximity alert reads altitudes of 100, 50, 30, 20 and just 10 ft above the ground.

Just nine seconds before impact, the air traffic controller appeared to realize his mistake and ordered the fire truck to stop.

A second later, the landing gear touched down on the runway, and soon First Officer Mackenzie Gunther handed over control of the plane to captain Antoine Forest, officials said.

As the plane sped down the runway, the air traffic control tower was heard once again ordering the fire truck to stop before the recording abruptly ended.

It now remains unclear whether it was the same air traffic controller who gave both the Air Canada plane and the fire truck permission to enter the runway.

Two controllers were on duty at the time; one managed the active runways and LaGuardia’s airspace, while the ‘controller in charge’ was responsible for the safety of operations.

One of them also acted as a ‘ground controller’, directing all movements on taxiways rather than active runways, but Homendy said it was unclear which of the two controllers handled this position.

He noted that combining positions during the night shift is standard practice at LaGuardia, one of the nation’s largest airports.

Air Canada plane crashed onto the runway at 150 miles per hour Sunday night

The two controllers worked a shift that typically started at 10:30 p.m. and lasted until 6:30 a.m., when air traffic controllers have historically experienced fatigue.

‘The midnight shift, as a reminder, is an issue where we have repeatedly raised concerns about fatigue at the NTSB,’ Homendy said.

‘We have no indication that this is a factor here, but it is a change we have focused on in past research.’

At least one of the air traffic controllers continued to work for several minutes after the fatal crash.

“Normally they would be relieved,” Homendy said at a news conference. ‘We have questions about this. Was there anyone to remove that controller? ‘We don’t know that yet.’

Investigators are also looking into the possibility that the fire truck did not have a working transponder; This would leave controllers without an important warning about the danger on the track.

An initial investigation showed the truck’s Airport Surface Detection Equipment (ASDE-X) surface security system failed to trigger alerts for controllers, Homendy said at the press conference.

The system that allows an airport controller to monitor the movements of planes and vehicles did not alert during the crash between Air Canada and Air Canada on Sunday night.

LaGuardia is one of 35 major U.S. airports with an advanced surface surveillance system that helps eliminate dangerous runway incursions and prevent accidents.

Controllers at these airports have an ASDE-X display in the tower that is supposed to show them the location of each aircraft and vehicle.

As recently as last May, the FAA called on airports with advanced surface surveillance systems like LaGuardia’s to equip their vehicles with transponders.

Passengers departing from New York’s LaGuardia Airport had to take a taxi past the wreckage, which was still visible

Although the NTSB does not recommend that vehicles on airport grounds have transponders, they should be standard equipment, Homendy said.

‘Air traffic controllers must know what is ahead of them, whether on the airport surface or in the airspace. “They need to have this information to ensure security,” he said.

The Port Authority of New York and New Jersey, which operates the airport, said it “could not comment due to the ongoing investigation” when asked about the lack of a transmitter on the fire truck.

While the investigation into the fatal crash continues, passengers landing at New York airport were shocked to see debris still lying on the runway.

‘At first I was shocked by the closeness, it was right there. “It’s shocking, you land and that’s the first thing you see when you get onto the tarmac,” said Sherrie Katanach, who was flying from Chicago. he told the New York Post.

“This was incredible to me,” added Sherman Criner, returning from a longshoremen’s convention in New Orleans. ‘I thought they would get it off the runway as quickly as possible, but from the plane you could see it was still sitting there.’

The scene will not be cleared until the NTSB investigation is completed, officials said.