ACT Chief Coroner Lorraine Walker has tested positive for COVID, resulting in the hearings being postponed until 2023.

The inquest was announced in July 2021, but the wait for information on how it took 45 minutes for an army helicopter's crew to alert the ACT Emergency Service Agency they had started a fire will continue.

On Monday, the court heard the crew on board the MRH-90 Taipan helicopter were landing for a toilet break when they inadvertently ignited the monster blaze.

They were scouting remote helipads in preparation for bushfire season, when they landed with their searchlight still on and started the fire in the Orroral Valley.

An on-board recording heard one of the helicopter's passengers yell "Come up, come up, we've started a fire, turn the searchlight off".

The helicopter only stopped for about one minute before returning to Canberra airport, but neither the pilots nor their passengers contacted emergency services to let them know they had started a fire, which one pilot estimated was already "200m by 200m" when they evacuated.

The pilot insisted he was "concerned we were going to fall out of the sky" because of aircraft damage.

The fire, which burned for five weeks, was declared out of control after 6pm when more than 1000ha were alight and would eventually grow to burn 87,923ha throughout the ACT.

Ms Walker opened proceedings by saying the inquest wasn't about "crucifying any individual or decision made in the heat of the moment".

"We're here to explore how we can learn from it with a view to enhancing everyone's safety in the future," she said.

Australian Associated Press