The collision of the commercial American Airlines plane and a Black Hawk helicopter at the end of January resulted in the deaths of everyone involved.

The plane was coming to land at Ronald Reagan National Airport, while the Black Hawk was in the progress of doing a training exercise.

Both aircraft crashed into the Potomac River and investigations were launched to discover what were the causes of the crash.

Authorities were able to confirm that 64 passengers on the plane died along with the 3 individuals on the helicopter.

Investigators into the incident at the time found that the helicopter crew may have had bad information on their altitude before it was struck by the plane.

One of the pilots reportedly thought they were at 400 feet and the other thought they were at 300 feet. However, the NTSB is not yet prepared to say at what exact altitude the helicopter was at the point of impact.

Air traffic control asked about whether the helicopter had seen the plane seconds before collision (Chip Somodevilla/Getty Images)

National Transportation Safety Board Chairman Jennifer Homendy said: “We are looking at the possibility of there may be bad data.

“In addition to this, the transmission from the tower, that instructed the helicopter to go behind the plane, may not have been heard by the crew the pilot may have keyed her radio at the same second and stepped on the transmission from ATC.”

This has since been confirmed as the New York Times reported seconds before the collision the pilot failed to heed her flight instructor’s warning.

Around 8:46 p.m., when co-pilot Andrew Eaves requested approval for the helicopter’s pilots to use their own visuals instead of air-traffic control in order to avoid other air traffic. This was approved as it’s common practice to help speed things up, however, with that comes the risk of human error.

Rebecca Lobach also missed an order from Eaves, who was overseeing her training mission.

As well as this, officials found that the pilots ‘stepped on’ some of the air traffic controller’s instructions, this term means they inadvertently cut off Eaves when pressing the button to talk over the radio. This is believed to have contributed to them missing important information.

Many errors are thought to have contributed to the crash (Kayla Bartkowski/Getty Images)

Seconds before the crash, an air-traffic controller asked the helicopter if it spotted American Airlines Flt. 5342.

This was the last communication between the plane and the air traffic control.

Technology on the Black Hawk helicopter that would normally help air traffic control better track the helicopter was also turned off, which would be normal protocol if the training mission had been for real.

Brig. Gen. Matthew Braman, the Army’s director of aviation has made it clear that multiple things ultimately contributed to the crash.

He said: “I think what we’ll find in the end is there were multiple things that, had any one of them changed, it could have well changed the outcome of that evening.”