In one crash, a water airplane went down in rugged terrain while fighting a fire in Budawang National Park Thursday, police confirmed.
Reports indicated one of the aircraft's wings fell off before the plane crashed and fires burned near the wreckage, forcing water-bombing aircraft to fly sorties to keep flames under control as teams tried to reach the pilot's body, the Australian Broadcasting Corp. reported.
The second pilot's plane crashed as it ferried spare parts for helicopters used in the firefighting operation, officials said.
On Thursday, rescuers found the wreckage of the single-engine Cessna that had been reported missing on a flight between Moruya in New South Wales to Mangalore in Victoria state Wednesday, the ABC said.
The pilots' deaths raised to three the number of people killed from the bushfires burning in New South Wales.
News of the pilots' deaths came as the Defense Ministry apologized for the State Mine fire, which was sparked by a live-fire army exercise at the Marrangaroo Army Range last week.
Air Marshal Mark Binskin confirmed a training exercise led to the fire, which had burned thousands of acres and destroyed at least three homes at the foot of the Blue Mountains.
"The fire scale was on the lower end of the scale and there wasn't a fire ban. But when the activity occurred there was small fire that started," Binskin said. "I do apologize, because it has been identified that this fire was the start of this mine fire."
The bushfires -- Australia's worst since February 2009 fires that killed 173 people and destroyed more than 2,000 homes in Victoria state -- have destroyed at least 248 homes and other structures and damaged more than 150 others since Thursday, the Rural Fire Service said.
Two other recent bushfires were linked to Defense Ministry training activities, the ABC said.
A grass fire Saturday at the Cultana Training Area on South Australia's Eyre Peninsula was started during an artillery exercise involving smoke grenades and simulated explosions.
Live-fire exercises also were suspected to be the cause of a fire at the Townsville Field Training Area in Queensland in August, the ABC said. That fire destroyed the historic Dotswood Station homestead, built in the 1860s.