Another 15,000 employees will continue to be stood down without pay over the coming months, particularly those associated with its international operations, as the pandemic prevents almost all international travel.
Chief executive Alan Joyce said the decision was painful to make, but also necessary if the airline was to survive the impact of the pandemic.
In a release to the Australian Stock Exchange, Qantas said about 100 of its aircraft would be grounded for up to 12 months, with some for longer.
The airline will permanently retire its remaining six Boeing 747 aircraft six months ahead of schedule, and defer deliveries of new Airbus A321neo and Boeing 787-9 aircraft.
Joyce said that the fallout from the pandemic would affect the airline sector for many years to come.
"Right now all airlines are in the middle of the biggest crisis our industry has ever faced," he said.
He said the crisis had hit Qantas "very hard" and that "the impact will be felt for a long time".
Joyce said the airline planned to get back to 40 percent of its pre-crisis domestic flying from July, and "hopefully more in the months that follow".
He said he hoped that about half of its 15,000 workers that had been stood down would be working again by the end of the year.
The company was having "good discussions" with the federal government about possibly extending JobKeeper or some other form of support for workers in the aviation industry stood down for an extended period, he said.
"We're also in dialogue with state and territory governments about their border openings because, once that happens, we can get more of our people back to work," he said.
The moves are designed to reduce costs by $15 billion during an expected three-year period of lower activity, and then result in $1 billion per year of ongoing cost savings from the 2023 financial year.
Qantas also announced plans to raise up to $1.9 billion from investors.
Joyce said it was the company's first equity raising in a decade "and once we have recovered, this capital will help us take advantage of opportunities that emerge".
The moves mirror those taken by Air New Zealand, which is in the process of sacking 4,000 staff, and is rumoured to be ready to raise hundreds of millions of dollars to strengthen its finances.