Coulson Aviation boss visits wreckage

Steven Trask
The boss of Coulson Aviation has visited the NSW site of a fatal crash of the air tanker plane

The boss of Coulson Aviation has made an emotional visit to the southern NSW site where one of the company's water-bombing planes crashed killing three US airmen.

Captain Ian McBeth, first officer Paul Clyde Hudson and flight engineer Rick DeMorgan Jr were killed when their plane crashed and exploded during a bushfire mission on Thursday.

Coulson Aviation owner Wayne Coulson visited the crash site northeast of Cooma on Sunday as the company continues its search for answers.

"To see our aircraft on the ground, knowing we have had such loss of life, was devastating," he told reporters at the NSW Rural Fire Service headquarters on Monday.

Mr Coulson said his feelings of grief as he toured the site were "indescribable".

Coulson Aviation is a Canadian-based company while the three dead crew members were all from the United States.

The Australian Transport Safety Bureau on Sunday began downloading data from the plane's cockpit voice recorder.

This data had not yet provided any insight on what caused the C-130 Hercules plane to crash, Mr Coulson said.

"These are world-class flight crews flying a world-class and well-maintained aircraft."

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

The families of the three men who died will visit the crash site on Wednesday.