The military branch has announced retention bonuses of up to $600,000 to keep pilots in the service. It’s also giving them more flexibility over where they are based and which assignments they get.

The program, which is set to run through the end of 2028, comes as more and more pilots are opting to leave the service when their tour is done, moving into the private sector, where they can earn a higher salary (thanks in part to that industry’s own shortages). The bonus comes as the service faces a “tsunami” of pilot retirements.

The incentives will also apply to manned aircraft and drone pilots, combat systems operators, and air battle managers.

“The requirement to preserve critical skills in our Air Force has never been more important,” Maj. Gen. Adrian Spain, the training and readiness director at Air Force headquarters, said in a statement. “Retaining these professional aviators’ experience and expertise…is imperative in order to outpace future challenges.”

The amount of the bonuses will vary depending on how long the airmen are willing to stay on board.

Fighter and bomber pilots, mobility, search-and-rescue, and special operations pilots can earn between $30,000 to $35,000 a year on three- to four-year contracts. Signing up for another five to seven years could earn an extra $37,500 to $42,500 per year. And those who stay an extra eight to 12 additional years can pocket bonuses of $45,000 to $50,000 a year.

The USAF is asking Congress for $250 million to fund the pool.

The bonuses come as the Air Force has missed its annual recruiting target for pilots for eight consecutive years. And they seem to be facing a warm reception: The Air Force Times reports 210 airmen signed up for the program in its first 10 days.