WASHINGTON — Gen. Mark Welsh, the outgoing Air Force Chief of Staff, is confident the F-35A joint strike fighter will be declared operational before the end of the year, but remains "disappointed" that Boeing has been unable to develop the KC-46 tanker on time.

In an exclusive interview with Defense News, Welsh also described the idea of new F-22 production as "cost prohibitive," throwing water on the idea of a Raptor restart.

During his tenure as chief of staff, Welsh has consistently identified three major modernization programs for the service: the F-35A, KC-46A and what is now known as the B-21 bomber. And during his tenure, all three programs hit major milestones.

Of those three, the biggest challenge at the moment is the Boeing made KC-46A Pegasus tanker.

Last month, the Air Force announced Boeing would miss a deadline to have 18 tankers ready to go by August of 2017. Instead, those 18 aircraft will be ready come January 2018, barring any further delays. The company has already been hit with $1.5 billion in cost overruns; the development contract it is operating under caps the Air Force's liability at $4.9 billion, with the company having to eat the rest.

Speaking to Defense News June 13, Welsh said he was "disappointed" by the KC-46 delays, but expressed confidence the current issues with the refueling system would be worked out.

"The problems they are having that are causing the delay in the aircraft are things we can fix," he said. "We know how to fix axial loads and booms. We know how to fix drogue systems. It will get done. I'm just very disappointed it will not get done in the timeline we agreed to."

Asked whether the Air Force would seek either damages from Boeing for the delay or reparations in the next round of contract negotiations, Welsh said "clearly, it's something we're going to have to talk to Boeing about in great detail."

"We believe there should be consideration for not meeting that. Exactly what that means for details will have to be negotiated," Welsh said. "I think the negotiations that will start here pretty quickly, and the [discussions] that are ongoing now, will lead to the details on that. I don't have any idea where that will go."

Despite the delay, Welsh said he believes the KC-46 design remains solid, and will prove to be "a great plane for the Air Force."

Boeing Flight Test & Evaluation - Boeing Field - KC-46, VH004, EMD2, Initial Contacts with F-16, Boeing KC-46 Pegasus Tanker Refueling F-16, Edwards AFB 412th TW,
Boeing Flight Test & Evaluation - Boeing Field - KC-46, VH004, EMD2, Initial Contacts with F-16, Boeing KC-46 Pegasus Tanker Refueling F-16, Edwards AFB 412th TW,

Boeing's KC-46 tanker marked a key milestone on Jan. 24, 2016, by successfully completing its first aerial refueling test.

Photo Credit: Boeing

The tanker issues crop up as the F-35, long seen as the problem child for both the Air Force and Pentagon, is scheduled to declare initial operational capability (IOC) in the next few months.

The F-35A can go operational when the first squadron is equipped with 12 to 24 aircraft, and airmen are trained, manned and equipped to conduct three basic missions: close-air support, interdiction, and suppression and destruction of enemy air defenses.

The service has a five-month window, between a target date of Aug. 1 and a terminal date of Dec. 30, to go operational; the Marines declared their F-35B operational last year.

Asked about his confidence in the F-35 hitting that Dec. 30 deadline, Welsh was direct.

"Very confident. It'll happen this fall," Welsh said, adding: "It will bring a capability we don't have today. It will be the beginning of really modernizing our fighter fleet, which needs modernization badly."

Welsh also weighed in on the question of whether it makes sense to restart production on the F-22 Raptor, which was ended early after producing just 187 of a planned 749 buy.

Legislation from the House, released in April, would order the Air Force to look into whether such a restart made sense. Asked about the language in May, Welsh said it was not a "wild" idea, but clarified this week that he believes it's a flawed one.

"We think it is cost prohibitive," Welsh said about an F-22 restart. "I was asked recently if it was a wild idea from a crazy man – well, no. It was worth thinking through. But we believe it is cost prohibitive, so we don't think it's a solution to the problem of not enough capacity in the fighter wing."

For more from our exclusive interview with Welsh, keep an eye on Defense News and Defense News TV.

Twitter: @AaronMehta