The Pentagon admits the U.S. military is taking a risk by proposing the retirement of 29 legacy tankers in the fiscal 2021 budget while the successor Boeing KC-46A Pegasus is not considered operationally viable.

The Air Force is proposing the retirement of 13 KC-135s and 16 KC-10s in fiscal 2021, according to its budget request.

“We do have a requirement out there to keep 479 tankers, and we will continue to do that. The budget funds that,” Navy Vice Adm. Ron Boxall, resources and assessment director for the Joint Staff, said Feb. 10 during a Pentagon briefing.

Boxall said the Pentagon will watch the KC-46 program closely and adjust the tanker fleet as necessary to maintain the 479-tanker requirement.

The Air Force framed the KC-10 and KC-135 retirements as a tough choice but worth the risk. “We can’t continue to fund everything today that we have in our force today” because the service must pay for equipment the military will need in 2030, Maj. Gen. John Pletcher, deputy assistant Defense secretary for budget, said during a separate Feb. 10 Pentagon briefing.

The KC-46A program still faces unresolved Category 1 deficiencies revolving around the remote vision system (RVS) and the boom telescope actuator. A Category 1 deficiency means the government has identified a risk that jeopardizes lives or critical assets. The problem with the RVS is what the Air Force calls a “rubber sheet” effect that distorts the image on the visual display used by the boom operator during refueling operations. The actuator on the boom needs to be more sensitive to smaller receiver aircraft, such as A-10s and F-16s. Boeing has agreed to pay for the RVS design fix, while the Air Force will finance the design change to the actuator.

“It’s really hard for us to consider the KC-46 part of our operational capacity,” Lt. Gen. Jon Thomas, deputy Air Mobility Command chief, told Aerospace DAILY.

Air Force Chief of Staff Gen. David Goldfein voiced his displeasure to Boeing and asked the company’s CEO to focus on the KC-46 program even as it is fixing the 737 MAX. “The Air Force continues to accept deliveries of tankers incapable of performing their primary operational mission,” Goldfein wrote in a January letter.

“The tanker is not capable of all of its missions and won’t be until the problems with the remote vision system are fixed,” Thomas said.