Why does the United States Air Force continue to rely on the Boeing 767 in 2025? Not only does the US Air Force rely on the Boeing 767 today, but there is a non-zero chance that it could continue to do so until close to 2100. The Boeing 767 is the newest Air Force aerial tanker and is designated the Boeing KC-46 Pegasus.

The Boeing 767 may have been obsolete in the commercial passenger sector since 2011, when it was superseded by the Boeing 787 Dreamliner, but the dynamics are different in other sectors. Cargo airlines have continued to value the Boeing 767 due to its robust design, reliable CF6 engines, and the manufacturing discounts have made it more attractive. Likewise, the USAF does not prioritize the fuel savings of the 787 to the degree that commercial passenger airlines do.

The Air Force’s Most Modern Tanker

First, it should be pointed out that military procurement projects can sometimes be glacially slow. The US Air Force began its program to find a replacement for its oldest KC-135E Stratotankers in 2001. The KC-46 Pegasus finally entered service in 2019. For perspective, Boeing launched its 787 Dreamliner program in 2004, and it entered service in 2011. This means it took more than double the time for the Air Force to select and bring into service an existing (albeit modified) aircraft than it did for Boeing to develop a clean-sheet aircraft and bring it into service.

That said, the 787 was never considered for the tanker role; Boeing has not even made a freighter variant of the Dreamliner. The Air Force’s tanker program initially saw the Air Force select the Airbus A330 MRTT based on Airbus’s A330 airliner. But after court cases and legal action, the USAF instead selected the Boeing 767 to be its next-generation tanker in 2008 and then again in 2011.

Airbus developed its MRTT anyway, and it has proven to be the most successful tanker on the export market. The only export customers for the Pegasus have been Israel and Japan. Israel is the largest recipient of US military aid used to purchase US equipment, while Japan has a long history of only purchasing US military aircraft.

A Partial KC-135 Stratotanker Replacement

It is hard to exaggerate just how dominant the United States Air Force is in aerial refueling. Around 75% of all the world’s military tankers are in service with the USAF, meaning in this category, it really is « the US and the rest. » The KC-135 (based on the Boeing 367 that also gave rise to the 707) remains the backbone of the US tanker fleet. The Air Force retired the last of its KC-10 Extenders (based on the DC-10) in 2024.

The KC-135s are aging and will eventually need to be replaced. At the same time, the nature of warfare is changing. Tanker aircraft are increasingly at risk of long-range air-to-air missiles, and aircraft like the Chinese J-20 have been designed with the range and stealth to hunt them. This means, in future peer-on-peer conflicts, they will be pushed further back and their ability to operate near the frontlines will be evermore diminished.

That doesn’t mean they will be useless in the decades ahead. For example, in the recent Operational Midnight Hammer, the B-2 Spirits were refueled multiple times, including over the US and over allied airspace. The Air Force intends for the KC-46A Pegasus to be a partial replacement for the KC-135. It will be able to operate in permissive environments, but it will need another solution for tankers operating closer to contested airspace.

Planned USAF KC-46A Pegasus Procurement

The United States Air Force currently has around 370 KC-135s and around 96 KC-46s in its inventory and plans to procure 127 KC-46As by 2027. According to The War Zone, under its existing contract with Boeing, the Air Force plans to eventually receive 188 KC-46s. But that number is expected to grow. The USAF now has plans to acquire another 75 KC-46s, bringing the total to 263 aircraft.

The extra purchase is a stopgap to allow the Air Force to retire aging KC-135s and give it time to develop a next-generation tanker. The service is also reevaluating its requirements for future conflict, as threats continue to evolve. As of the time of writing, Boeing’s database shows it has delivered 106 KC-46 Pegasus tankers (767-2C), of which five were to Japan.

Boeing has a total of 62 tanker aircraft remaining on order. These include four for Israel and 58 for the USAF. The numbers do not match the 188 the Air Force has contracted to purchase; the difference may be that some orders have not been fully finalized yet. Separately, new ICAO regulations are set to enter force on January 1, 2027. Boeing is rushing to deliver the last of its commercial freighter 767-300Fs (and 777Fs) in 2026; after that date, the military KC-46 will be the only version of the 767 to remain in production.

USAF’s Next Generation Air Refueling System (NGAS)

Looking beyond the KC-46, the Air Force is looking for more options to partially replace its KC-135s with the Next Generation Air Refueling System or NGAS. Lockheed has offered a stealth aircraft option for the Air Force that would be able to operate in contested airspace, or at least, closer to contested airspace. Renderings of some pitches for the NGAS program depict autonomous tankers without pilots and cockpits. Notably, this is what the Navy is going for with its MQ-25 Stingray carrier-based tanker.

Meanwhile, in September 2025, The War Zone reported that the USAF is even considering tankers based on business jets. The development underlines the threat to USAF forward operating bases and the need to be agile and disperse into multiple airfields with smaller aircraft. Another potential solution is blended-wing-body aircraft. Most notably, JetZero is currently developing a demonstrator in partnership with Northrop Grumman.

One limiting factor is that the USAF has limited funds for projects like the Sentinel ICBM, the next-generation F-47, and other projects, which are placing a strain on its budget. Budget concerns are a limiting factor for stealthy tankers. Another consideration is that a clean-sheet novel autonomous system may be subject to cost overruns and many years of delays. One thing the Air Force desperately wants is for aircraft to be runway independent.

Boeing 767/KC-46A Has A Shot To Remain Until 2100

As stated, the Boeing 767 could remain in service with the USAF until 2100. Boeing delivered 15 KC-46As in 2022, 13 in 2023, 10 in 2024, and nine in the first three quarters of 2025. If the Air Force does purchase a total of 263 KC-46As, then around another 162 tankers remain to be delivered. At the current rate, this would take at least another ten years to fulfill. That said, with 767 freighter production ending in 2026, it’s unclear if Boeing will increase its KC-46 delivery rate.

All else equal, this suggests that the final Boeing 767 tanker will not be handed over to the US Air Force until at least 2035. The oldest KC-135 in service today is aircraft 57-1419. That aircraft is operated by the Arizona Air National Guard and was built in 1957. It has the distinction of being the oldest jet aircraft currently in service with the USAF.

The aircraft is now 68 years old, and it is unclear how much longer it will remain in service. If the final Boeing 767 tanker is delivered in 2035 and serves for the same amount of time, then it will be 2103 by the time it reaches 68 years old and retires. It should be noted that anything can happen over 70 years, and any discussion is speculative.

The Only Available Option To Replace Aging KC-135s

The USAF continues to rely on the Boeing 767, as that is the aircraft the service selected for its partial KC-135 replacement. The aircraft may be old for commercial passenger airliners, but the dynamic is different in a military context. Lacking a clear next-generation alternative to the 767/KC-46 and with its oldest KC-135s now approaching 70 years old, the service appears to be doubling down on the tanker.

Even with proliferating threats facing tankers, conventional tube-and-wing tankers like the KC-46 will remain relevant for the foreseeable future. They will be able to refuel aircraft over friendly skies and bring aircraft to the forward bases, although they may not be able to bring the aircraft past those bases and into the fight. That may have to be the job of a future NGAS tanker.

One other thing that is notable about the Boeing 767-2C/KC-46A is its engines. While all the final Boeing 767-300F freighters are exclusively powered by the reliable General Electric CF6 turbofan, military tankers come with the Pratt & Whitney PW4000. Having lost bids on the Boeing 787 and Airbus A350, Pratt & Whitney is now out of the commercial widebody engine market. The KC-46A is likely the only widebody aircraft being built with PW engines. That said, JetZero has selected the Pratt & Whitney PW2040 engines for its BWB demonstrator.