Air Force Launches New Stealthy Tanker Program, with Delivery Projected for 2040

The Air Force launched its search for the Next-Generation Air-Refueling System (NGAS), a stealthy tanker project intended to deliver its first aircraft around 2040, with a Jan. 31 request for information to industry. The new tanker is to be capable of surviving in contested airspace, but the service is open to all ideas about its size and performance.

Contractors are invited to submit ideas for the NGAS that will be considered in an Analysis of Alternatives getting underway in October, according to the announcement on Responses to the RFI are due March 2.

The RFI marks the formal start of what has previously been called “KC-Z.” The KC-X program became the KC-46 now being acquired; the KC-Y has become the so-called “bridge tanker” still in definition, and KC-Z the Air Force now refers to as NGAS, or “increment three” of its three-phase tanker recapitalization effort.

The Defense Innovation Unit and the Air Force are already looking at concepts for a future blended-wing body tanker, but the Jan. 31 solicitation specifically leaves open the configuration.

The Air Force “is interested in innovative solutions in all size and performance classes that might address the stressing mission requirements” of delivering fuel in contested airspace, the announcement said. The speed of the aircraft concepts submitted “should be compatible with modern receivers.”

The concepts put forward can have novel technologies or operational concepts, but the Air Force said all the risk needs to be ironed out to a Technology Readiness Level of 6—meaning a representative model or prototype system has been tested in a relevant environment—before 2032.  

Air Force Secretary Frank Kendall, speaking on a Council on Foreign Relations webinar on Jan. 11, said the threat posed by China is driving the Air Force away from traditional tankers, wherein a commercial aircraft is adapted into a mobility aircraft.

“The threat’s taking that freedom away from us,” he said, adding that with new cargo and tanker aircraft designs, USAF has to put “a high premium on survivability.” Chinese and other adversary aircraft and missiles can track tankers and shoot them from long range, compelling the Air Force to move toward survivable concepts, he said. The new tanker will have to “move beyond” traditional concepts and “survive in an environment the current fleet hasn’t had to work [in].”

In June 2022, the Air Force sent out a request for the “Advanced Aerial Refueling Family of Systems,” a dual-track program seeking a KC-46 follow-on with additional capabilities like a communications node and advanced navigation systems, while separately pursuing an advanced tanker with the survivability to operate near enemy airspace. The NGAS is now defined as that second track.

Kendall has indicated he thinks an improved KC-46 will likely be the solution to the “bridge tanker” requirements, consistently downplaying the idea of a competition.

A proposed amendment to the fiscal 2023 defense budget mandating a bridge tanker competition didn’t make it to the final bill, but supporters have said they will try again this year.

The request for info for the NGAS instructs industry to provide detailed performance characteristics of potential aircraft, including their size and weight, “takeoff and landing, climb, cruise, and representative mission performance.” The Air Force also wants to know if the aircraft proposed can use “regional or improvised airfields or other, non-traditional basing.”

The new tankers will have to be able to receive fuel in mid-air as well as provide it to other aircraft. The respondents should also identify the level of maturity of the designs, what the greatest risk areas are, and how contractors would mitigate them in a development program. Officials want “timelines to fielding” the proposed solutions.

Respondents should explain how their solutions might “change the way aerial refueling operations would be executed,” what operational or support changes would be needed to introduce these new concepts, and how “your proposed solution [will] increase, improve, or expand the current and planned capabilities of the tanker fleet (including KC-135, KC-46, and Bridge Tanker).”

The concepts also have to address how they will support unmanned aerial systems and “address anticipated threats … in the 2040 timeframe.” Industry respondents also need to submit their ideas on how they will counter cyber threats to their aircraft concepts, and broadly, identify the “high-level cost implications” for any new technologies put forth. Potential offerors also have to state what kinds of engines they would put on their aircraft and what kind of fuel savings they can achieve versus present-day tankers.

The program will make use of digital modeling and simulation techniques and any proposals must use a modular, open-systems architecture.

The Air Force also wants to know if the proposers can offer “innovative teaming arrangements of traditional military prime contractors with non-military contractors to achieve a mix of experience in advanced aero-configuration design, lean programs, and rapid airframe development and manufacturing.” The service is looking to expand it supplier base both to increase competition and avoid “vendor lock,” wherein a particular contractor enjoys a virtual monopoly on upgrades and software.

Industry has already offered up a variety of approaches to future tankers, ranging from blended wing body concepts to small, highly stealthy tankers that could penetrate heavily defended airspace along with strike aircraft.

Last month at the annual American Institute of Aeronautics and Astronautics convention and exposition, Boeing unveiled a stealthy-looking hybrid blended wing body concept for mobility applications having a butterfly empennage and embedded engines. Lockheed Martin has also shown stealthy BWB-type concepts for future airlifters and tankers.

Kendall said there’s no commercial blended-wing body concept the Air Force can take advantage of “yet,” but the service is looking at such concepts with the DIU because commercial variants could also significantly reduce the airline and freight industry’s consumption of fuel.   

Kendall has also designated airlift as one of the three “cross-cutting” enabler mission areas that touch all of the Air Force’s activities—the other two being electronic warfare and munitions—and underlie all of his seven “operational imperatives.” Each enabler has been assigned an operational and acquisition co-leader to facilitate the development of capability roadmaps.