Tragic footage has surfaced that captures the final moments of doomed C-130 Hercules bomber carrying hero firefighters.

Confronting footage has emerged of the moment a large air tanker crashed while fighting raging bushfires in NSW, killing the three US firefighters on board.

Captain Ian McBeth, first officer Paul Clyde Hudson and flight engineer Rick DeMorgan Jr were on board the C-130 Hercules aircraft when it crashed near Peak View, northeast of Cooma, last week.

Footage taken moments before the crash shows the water bombing aircraft dropping pink fire retardant over a bushfire burning in the area.

“There he goes! He has done that one and he’s going to do the other one,” a man filming the plane can be heard saying.

The air tanker then disappears into a thick cloud of smoke for a few seconds before an explosion is heard and a large ball of flames can be seen crashing to the ground.

A NSW Police spokesman today said the force was aware of the video “and it will form part of the coronial brief of evidence”.

The video has emerged as the families of the men who died prepare to visit the crash site today.

The three men, who previously worked with the US military in war zones around the world, were brought in to help fight bushfires that have devastated large parts of NSW and Victoria.

The RFS lost contact with the large air tanker about 1.30pm, with a panicked call coming in not long after that saying the plane had crashed.

The audio of the call was broadcast by Nine News.

“Fire comms … message red speak to your captain. Message this is red,” a man could be heard saying.

The man says the word “crashed” before the audio cuts out briefly.

“Yeah fire comms … it’s just a ball of flames. Over.”

Coulson Aviation, the company that operated the C-130 Hercules, temporarily grounded all their large air tankers following the crash.

Chief executive officer of the company, Wayne Coulson, visited the crash site on Sunday and said his feelings of grief were “indescribable”.

“To see our aircraft on the ground, knowing we have had such loss of life, was devastating,” he told reporters in Sydney on Monday.

The Australian Transport Safety Bureau (ATSB) on the weekend began downloading data from the plane’s cockpit voice recorder although this is yet to provide any insights on the cause of the crash.

There were hopes the recordings would shed some light on what happened in the moments before the tragic incident.

“It generally records the last two hours of a flight. It will record the pilot, co-pilot and the flight engineer’s discussion in the cockpit,” ATSB boss Greg Hood previously said.

“Without knowing what exactly happened we don’t know how useful it is.”

Investigators have been interviewing witnesses in Cooma and using a drone to produce a three-dimensional map of the wreckage.