The bodies of two US airmen killed in a plane crash while fighting bushfires in southern NSW will begin their journey home today as investigations continue into the tragic accident.

There were sombre scenes in Sydney today as the bodies of two of the United States airmen, killed when their firefighting plane crashed in southern New South Wales last month, were loaded onto a plane.

Captain Ian McBeth, first officer Paul Clyde Hudson and flight engineer Rick DeMorgan Jr died when their waterbombing tanker crashed northeast of Cooma on January 23.

Two coffins, draped in the US flag, passed through a guard of honour as they were placed on a United Airlines flight at Sydney’s Kingsford Smith Airport on Wednesday morning bound for Houston, Texas.

The bodies of Mr McBeth and Mr Hudson were to be repatriated.

Devastated family and friends attended a memorial service for the men on January 30 at the Richmond RAAF base, where the trio were posthumously awarded a commissioner’s commendation for service by the NSW Rural Fire Service.

The RFS had leased the aircraft from Coulson Aviation in the US, who identified the victims.

“Without dwelling on the enormity of loss, what I do need to say is: that loss would’ve been considerably worse if not for the thousands of men and women on the front line, and these special aviators that look after them from above,” RFS Commissioner Shane Fitzsimmons said.

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Mr Fitzsimmons said Mr Hudson was a humble man and an absolute professional, while Mr DeMorgan Jr was a committed and studious aviator.

Captain McBeth’s father, Bill, struggled to contain his grief as he addressed the memorial.

“A few minutes ago the chaplain asked us to describe Ian in a few words. His wife Bowdie, who loved him dearly, said he was 100 per cent. A 100 per cent man,” he said.

NSW Premier Gladys Berejiklian said earlier she was “heartbroken” for the men’s families.

“The tragic accident, the loss of their lives demonstrated the risks that all of our firefighters put themselves in front of every single day,” she said.

The flight, taking almost 16 hours, is scheduled to arrive around 10am Wednesday local time.

With AAP