It was revealed on Monday the defence helicopter crew took 45 minutes to alert the ESA to the location of the blaze after it was sparked by the aircraft's landing light.

The Canberra Times has revealed at least one official inside the agency's incident management team had concerns about the military's presence in Namadgi on January 27.

ESA commissioner Georgeina Whelan said the helicopter pilot's first priority was to ensure the safety of himself and his crew.

Defence has defenced the crew's actions, saying the location of the blaze was handed to the ESA after it made an emergency landing at Canberra Airport.

"What I do understand from reading the report was the primary responsibility of the pilot would have been to the safety of his crew, and himself," she told ABC Radio Canberra.

"It certainly would have required [contacting] the authorities, I'm not an expert with regard to the communication protocols they would have had in the aircraft."

Commissioner Whelan said ACT authorities had found the blaze within 20 minutes of ignition, and firefighting aircraft had been at the scene within half-an-hour.

"It did take 45 minutes and certainly I am sure that is something Defence will consider and and will continue to consider into the future," she said.

"What I do know is our towers in particular, three of our towers identified the fire very readily, as did the community and we responded within 20 minutes of the incident occurring."

The commissioner said she did not blame "any one individual" for the fire that tore through 80 per cent of Namadgi National Park in "inaccessible" and "challenging" terrain.

"We have subsequently walked that fire ground ... it's only when you actually see the point of ignition you realise how inaccessible that countryside was," she said.

READ MORE: How the ACT's Orroral Valley fire grew

The Canberra Times has revealed a senior member in the ACT's bushfire response questioned the need for the helicopter mission.

Commissioner Whelan said it was common for aircraft to undertake operations like this one during bushfires to identify fire trails and potential landing zones.

"It is heartbreaking that we've lost 80 per cent of Namadgi National Park, I don't hold any one individual responsible, like every commissioner across the country, I am just very grateful from an ACT perspective we did not lose any lives, we did not lose homes," she said.

"We have some significant damage to our rural land holders but I'm very grateful for the support and resources the ADF did provide for us because it also prevented a number of major fires from crossing our borders.

"For that, I think we all have to be grateful. We have certainly learnt a lot from last season."