The U.S. Air Force has decided to end the KC-Y program for buying 150 commercial tankers as a bridge to a future Next-Generation Air-Refueling System (NGAS) tanker–the formerly known KC-Z–and may end up buying 75 more Boeing [BA] KC-46As instead, as the service considers an Analysis of Alternatives (AoA) on NGAS.

“A lot of this, the AoA will look at, but the kinds of the things that I think are relevant are the ability to go deeper into contested airspace, more advanced self-protection and networking capabilities, ” U.S. Air Force acquisition chief Andrew Hunter told reporters on March 6 at the Air & Space Forces Association conference in Aurora, Colo., in response to a question on the possible features of a next generation tanker, “That initial KC-Y requirement was a step in that direction, but it wasn’t a progression all the way to those kinds of capabilities.”

NGAS would be a new program that would require congressional authorization in fiscal 2024.

“The goal here is to accelerate that capability [NGAS], “Hunter said. “We definitely would like to get an Increment 1 in the mid-to-late 2030s. There will be a trade space that the AoA will look at of what can we field relatively quickly that could substantially improve our ability to operate in contested airspace and what might take more time which we would maybe defer to a later increment. It’s not necessarily all airframes. Some of that could be in new systems–more advanced self-protection systems.”

While KC-Z was not to field until the 2040s, NGAS is “a decade or more acceleration,” Hunter said.

As the Air Force continues to retire older KC-135R tankers, congressional defense authorizers set a minimum fiscal 2023 requirement for 466 tankers. The KC-46A fleet and possible future tankers would replace more than 400 Boeing KC-135Rs and KC-10s in the coming decades.

Before the KC-Y cancellation, the Air Force had been examining whether to go forward on a program to buy 140-160 KC-Ys to fill the gap between a planned final delivery of the 179th KC-46A in 2029 and a future tanker, which could include stealth, connectivity, and fuel efficiency advances (Defense Daily, Aug. 12, 2022).

Industry had worked on a business case analysis for KC-Y to help inform requirements on the then-envisioned commercial tanker.

Lockheed Martin [LMT] had geared up for a KC-Y competition and, in January last year, said that the company planned to build the LMXT refueler, based on the Airbus A330, in Mobile, Ala., and Marietta, Ga. (Defense Daily, Jan. 31, 2022).

Air Force Materiel Command’s KC-Y program had outlined a number of challenges for commercial derivative aircraft, such as the KC-46A Pegasus tanker (Defense Daily, July 20, 2022).

“Primary depot support challenges surround unscheduled maintenance and unplanned parts supportability discovered during schedule letter checks,” the program said on July 13 last year in a response to questions from an unidentified contractor. “Additionally, parts tracking once they are in supply has been problematic, as well as engineering disposition challenges for repairs outside of task orders. Lastly, excessive and repetitive inspections to meet FAA [Federal Aviation Administration] requirements based on commercial flying program versus USAF flying hour program has been a challenge.”

“Letter checks” are scheduled maintenance with A and B checks falling under light maintenance, while C and D checks fall under heavy maintenance.

Air Force Secretary Frank Kendall told the Senate Armed Services Committee on May 3 last year that “as we looked at the requirements, it doesn’t look as necessary or as cost effective as it once did to introduce another aircraft as KC-Y.”

Nevertheless, the KC-Y program office continued its work, should the Air Force have decided to move forward on KC-Y.

The House’s version of the fiscal 2023 defense authorization bill would have allowed the Air Force to buy KC-Y without an open competition with an explanation from the Air Force secretary to explain such a decision (Defense Daily, June 23, 2022). The final fiscal 2023 defense authorization bill did not contain that provision, however.