DAYTON, Ohio — The U.S. Air Force expects to release its formal request for information for a KC-135 tanker recapitalization in September, which will pave the way for an official acquisition strategy for the program it previously referred to as a “bridge tanker.”

In a roundtable discussion with reporters at the service’s Life Cycle Industry Days event in Dayton, Ohio, the deputy program executive officer for mobility aircraft, Scott Boyd, outlined the force’s plan for the next two stages in a major overhaul of its tanker fleet.

But, Boyd cautioned, much remains undecided over how to eventually field an advanced refueling aircraft it now calls the next-generation aerial refueling system, or NGAS.

The Air Force originally referred to its two final stages as KC-Y, or the bridge tanker, and KC-Z, following its procurement in recent years of the KC-46. Those three modernization stages are to replace the service’s legacy KC-135 Stratotanker fleet.

The Air Force initially had loose plans for KC-Z to arrive in the 2040s. The service originally planned to buy about 150 tankers as an interim step until then — possibly more KC-46s, although Lockheed Martin is pitching its LMXT strategic tanker, based on Airbus’ A330 Multi Role Tanker Transport, as an alternative.

However, in March the Air Force shifted course on its future tanker modernization effort. Top leaders announced plans to speed up the acquisition of its most advanced future tanker, which was redubbed NGAS, to the mid- to late-2030s, and to cut in half the number of interim tankers it would buy.

Top service officials worry China’s advancing air capabilities will make it increasingly difficult for existing tankers to survive in highly contested airspace, and that a more advanced, survivable refueling aircraft able to operate in combat zones will need to hit the fleet sooner than anticipated. Air Force Secretary Frank Kendall said in March that NGAS would require a new design, not derived from a commercial aircraft, and that a blended wing design is a possibility for its body.

During Monday’s roundtable, Boyd stressed the service’s acquisition strategy is not set in stone.

“Doesn’t matter what any person, senior leader, otherwise has said: We don’t know what our acquisition strategy is,” Boyd said. “We’ve engaged with Congress on that as well to try to make clear that we still don’t know what our strategy is.”

But Boyd said the Air Force is working through a process on joint capabilities, integration and development in order to get the final requirements for the interim tanker approved by the Pentagon.

That should be finished by the end of September, he said, and the Air Force expects to release the request for information around the same time or shortly afterward, including what requirements the Air Force wants from industry.

“That will be the first time anyone in industry has seen the formal Air Force requirement and can have a chance to respond,” Boyd said. “Everything we’ve done prior to this, with engaging with industry, has been based on draft documents, draft requirements, ideas of requirements. That’s why that’s sort of a milestone event, to finally engage with a real requirement.”

Industry will then respond to the Air Force’s solicitation with data including estimates on how quickly a company could deliver an aircraft if selected, Boyd said. The Air Force will then use all that information from industry to finish its business case analysis and settle on its long-awaited acquisition strategy.

Boyd said the Air Force expects to have its strategy finalized and approved around the third quarter of fiscal 2024. He noted the service is leaving that window for finalizing the strategy as wide as possible because there are potential unknown factors.

Top Air Force leaders, such as Kendall and acquisition chief Andrew Hunter, have repeatedly suggested the service might forgo a competition for this wave of tanker recapitalizations and instead go straight to buying more KC-46A Pegusus tankers from Boeing.

Boyd said Monday that the Air Force needs to study market research, evaluate feedback it collects from industry and complete a business case analysis. All those steps will happen no matter what path the Air Force takes, he explained, and the service will consider all life cycle costs as part of this business case analysis.

The Air Force’s requirements for the recapitalization won’t make a KC-46 choice a foregone conclusion, Boyd said, but it will remain to be seen whether the market research shows a viable competitor exists, other than the KC-46.

He suggested Kendall’s and Hunter’s remarks reflect a recognition that the requirements going into the interim tanker recapitalization’s process “are not revolutionary” and don’t require a new aircraft.

“When they recognize that, I think that sort of helps influence how they talk about the program,” Boyd said. “It can be potentially satisfied by the [KC-46], but we still have to do our due diligence.”

Boyd noted he has not felt pressure from lawmakers or elsewhere within the Air Force to shift course on the recapitalization.

He also said the name change did not represent “some dramatic shift” in the Air Force’s approach, but largely reflected the accelerated timeline for tanker modernization.

The Air Force is still figuring out what NGAS will be, Boyd said. In early fiscal 2024, he added, the Air Force will start its formal analysis of alternatives, which is expected to produce recommendations on what would be needed to meet the service’s goals for NGAS. The service believes it could field an NGAS tanker as early as 2035, he noted.

Even though the service has dramatically accelerated its NGAS schedule, Boyd explained, it will still need the KC-135 recapitalization as an interim step.

Hanging over the process is the service’s decision to slash the number of purchased interim tankers to 75. And, Boyd said, it remains to be seen whether the Air Force will strike the right balance between that reduced buy and when NGAS might actually arrive.

“If we end up getting 2035 wrong, then perhaps we got the quantity of what we needed [on KC-135 modernization] wrong,” Boyd said. “That’s everyone’s concern — Air Force has that same concern, Congress has that concern, industry certainly has that concern.”