Although Congress is poised to boost the maximum annual pilot retention bonus to $35,000, that would still fall far short of the $48,000 per year the Air Force says is necessary to keep fighter pilots from leaving to fly for commercial airlines.

In conference to iron out differences between the House and Senate versions of the defense authorization bill, lawmakers tentatively agreed to cap the Aviator Retention Pay bonus at $35,000 for each year pilots agree to stay with the Air Force, according to the conference report released Nov. 30. This means they could receive up to $315,000 for a maximum nine-year contract.

The bonus for pilots of manned aircraft has been capped at $25,000 since 1999, allowing pilots who continue serving to receive up to $225,000 over nine years. But this summer, Air Force Secretary Deborah Lee James and Chief of Staff Gen. David Goldfein began sounding the alarm about the exodus of fighter pilots from the service, which Goldfein termed a "quiet crisis." James and Goldfein said that nearly doubling the retention bonus to $48,000 — which would give pilots as much as $432,000 extra — could help stem the losses.

When asked whether the reduced amount of the bonus increase would be enough to hold on to pilots, the Air Force said it could not comment on pending legislation

Airmen flying remotely piloted aircraft also became eligible this year for a maximum $35,000 annual retention bonus, though they could only sign up for a maximum five-year extension.

In keeping with the Air Force's current practice of offering pilots anywhere from $10,000 to $25,000 for every year they extend their contracts, not every pilot will get the maximum possible bonus proposed in the defense authorization bill. In the joint explanatory statement accompanying the bill, lawmakers said that Goldfein told them the bonus will be tailored by platform, based on the Air Force's requirements.

In an op-ed for Defense One in July, James and Goldfein said the shortage of fighter pilots was expected to grow from 500 to 700 by the end of the year, which would represent a 21 percent shortfall. Maj. Gen. Scott Vander Hamm, assistant deputy chief of staff for operations at Air Force headquarters, said in August that the shortage could swell to about 1,000 pilots by 2022 unless the Air Force takes steps to reduce the departure of pilots.

James and Goldfein said a major problem contributing to the pilot shortage is that 17 years of inflation has blunted the effectiveness of the pilot retention bonuses, and the "take rates" of pilots accepting them are disappointing. The Air Force usually hopes to have an overall pilot take rate of 65 percent, but in fiscal 2015, that had fallen to 55 percent.

At the same time, a generation of Vietnam-era pilots is retiring from flying commercial airliners. Private airlines are eager to recruit experienced, proven military pilots, and are offering hefty salaries to entice them.

In addition to boosting monetary bonuses, the Air Force needs to take other steps to improve pilots' quality of life and quality of service, Air Force leaders said. For example, Goldfein said, high operations tempos have strained fighter pilots by keeping them away from their families.

To help fix that problem, Vander Hamm said, the Air Force must be smarter about how it schedules training exercises so they do not take pilots away from home once again after they return. The Air Force also needs to give pilots some flexibility to choose their next assignments.

Pilots are also disappointed when budget and other shortfalls keep them from flying as much as they'd like to, Goldfein said.

Lawmakers signaled they intend to hold the Air Force to those promises.

"The conferees also expect the services to continue developing and implementing policies to tackle non-monetary reasons for low aviator retention rates," the joint explanatory statement said.