While much is said about how many fighter jets a country has, those jets have little ability to project power more than a few hundred miles from their forward operating bases without aerial refueling. There are two types of aerial refueling: probe and drogue and flying boom. The flying boom method uses a rigid, telescoping tube for faster fuel transfer and is the most relevant to this article.
The workhorse of the United States Air Force aerial refueling remains the KC-135 Stratotanker, which is related to the Boeing 707 airliner. However, the tanker being purchased now by the Air Force is the KC-46A Pegasus, based on the Boeing 767. Unlike Boeing 767 freighters, the KC-46A is powered by a pair of Pratt & Whitney PW4000 turbofans. For now, the KC-46A is both the top choice for aerial refueling and the only choice for new air tankers as the Air Force works on developing a next-generation tanker.
The Need For Tankers
For fighter jets to project power any significant distance from their nation’s borders, they need aircraft carriers, forward operating bases, lots of tankers, and other support elements (like transport aircraft). Ideally, a military will have all of these, and the United States has them in spades. During a single raid over Iran in 2025, the United States Air Force used more tankers to supply its B-2 Spirits and other aircraft than any other country possesses.
Israel was able to sustain operations over western Iran, but this was taxing its limited fleet of tankers to the limit. Additionally, the farthest Israeli strike was to take out a rare Iranian tanker in Mashhad, underscoring how high a target these aircraft are. The United States Air Force possesses around 75% of the world’s tankers, depending on what is counted as an aerial refueling tanker.
The primary tankers in Europe are the Airbus A330 MRTT, although other European aircraft like the Airbus A400M Atlas can also serve in a refueling role. The US Marines use MV-22 Osprey tiltrotors in a tanker role, while the US Navy uses Super Hornets to refuel other Super Hornets. The Lockheed Martin C-130/C-130J Hercules/Super Hercules is widely used as a tanker (as the KC-130/J). Some of these aircraft, like the KC-130/J, can only use the probe-and-drogue method of refueling. This article focuses on the KC-135 and KC-46 tankers.
The Boeing 767-2C/KC-46 Pegasus A Partial Solution
The newest USAF tanker is the KC-46A Pegasus, based on the Boeing 767 airliner, specifically the 767-2C variant. It was selected after a long, drawn-out selection process that saw the US Air Force choose the Airbus A330 MRTT before settling on the Boeing 767. The aircraft is partially replacing the KC-135 Stratotanker as well as the now-retired KC-10 Extenders.
The Air Force is purchasing the Pegasus as it is the aircraft available to replace very old tanker airframes in need of replacement. The oldest KC-135 aircraft still in service was delivered in 1957. The Pegasus is a conventional tube-and-wing aircraft. It is suited for operations in friendly skies, but would likely struggle in contested skies, even with air defense measures.
Consequently, the Air Force is investigating options for its Next Generation Air-refueling System (NGAS). It is unclear what form or forms NGAS will take, although Lockheed Martin has released renderings of a stealth, pilotless solution. At the same time, JetZero is developing a blended wing body demonstrator for the USAF, which is expected to first fly in 2027. The USAF may want a VTOL aircraft to be runway independent. Alternatively, it may also consider the Navy’s new MQ-25 Stingray tanker.
The Pegasus is hitting turbulence.
USAF Ordering More KC-46 Pegasus Tankers
Boeing currently shows 62 KC-46A Pegasus tankers in its backlog. Four of these are for Israel, and the remaining 58 are for the US Air Force. Boeing’s data shows it has delivered a total of 106 KC-46A tankers, of which the vast majority (101) are for the United States. The program’s only two export customers are Israel and Japan, and Japan has now received all five tankers Boeing lists as having been ordered.
According to Boeing, the most recent US Air Force order for the KC-46 was in November 2024, when the service ordered 15 tankers. But these numbers are now out of date as the US Navy has just placed a $2.47 billion order for 15 more KC-46s. This brings the total USAF order of Pegasus tankers on contract to 183 for all customers (including Japan and Israel). This new contract is for Lot 12 and is to be completed by 2029.
Meanwhile, Israel is also in the process of increasing its order for KC-46A Pegasus tankers from four to six. This will allow the country to retire its aging fleet of Boeing 707 tankers (similar to the KC-135) and expand its fleet. The US approved the potential sale of eight of these tankers to Israel in 2020. In 2024, Defense Post reported Japan was seeking to expand its order to 15 by ordering another nine examples.
Blowing Past The 179 Initial Buy Plan
The United States Air Force had originally only intended to purchase 179 KC-46 Pegasus tankers to replace its KC-10s and partially replace its KC-135s. However, the service now finds itself in a tanker crisis with its aircraft aging, retiring, and not having enough replacements. As stated above, no next-generation aircraft is yet available for the USAF to purchase to fully replace its KC-135s.
Any new tanker program would likely take many years and would be at risk of cost overruns and delays. A new tanker likely wouldn’t enter service until the 2030s. Until then, the USAF has little option but to purchase more KC-46As to bridge the gap. While problems have emerged with the KC-46A program, like cracks in the wings and a boom shearing off, any new program would be at much higher risk than the mostly mature KC-46A program.
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Boeing KC-46A Pegasus tankers by the numbers |
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|---|---|
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Number delivered to USAF |
101 (per Boeing) |
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Latest order |
15 (placed November 2025) |
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Originally planned KC-46 purchase |
179 |
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Current planned purchase |
188 (per TWZ), 183 (per hearing) |
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Total planned purchase |
263 (per TWZ) |
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Number of KC-135s in service |
377 |
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Congressionally mandated tanker fleet |
466 |
In September 2025, The War Zone reported that the US Air Force is now expecting to eventually receive 188 KC-46As under its existing contracts with Boeing. The discrepancy with the numbers listed by Boeing is likely due to the exact status of these orders, as some are not firm orders. However, the Air Force is now expecting to acquire an additional 75 examples that would bring the total to 263.
From KC-97 To KC-46: A Brief History Of US Air Force Tankers
The first tanker was propeller-driven and today they are based on airliners (the Boeing 707 and 767), but this is soon set to change.
Acquiring KC-46As While Modernizing KC-135s
Even 263 KC-46As are not enough to fully replace the Air Force’s fleet of KC-135s. The Air Force is required to maintain a fleet of 466 tankers, though Washington wants to increase this by 2027. In a hearing before the Armed Services Committee, the USAF stated it has “prioritized KC-46A tanker production, which is replacing a significant portion of the aging fleet. This program represents the first phase in a broader strategy to ensure rapid global mobility for the future.”
It added that a total of 89 KC-46As had been delivered to the Air Force by April 2025 and that it planned to acquire 183 in total (it’s unclear why there’s a discrepancy with TWZ’s 183 figure). As stated, that number is likely to rise. It noted that, additionally, tanker recapitalization will be required to fully support the “Congressionally mandated floor of 466 tankers.” The hearing noted the cracks in the wings and efforts to overcome the aircraft’s issues.
The backbone of USAF tanker operations remains the KC-135. The Air Force is working on sustainment efforts focused on “upgrading the current fleet of 377 aircraft to ensure it meets the Air Force’s refueling needs.” Regardless of how many KC-46As the USAF eventually purchases or what happens with its NGAS program, the KC-135 is to continue as a workhorse expected to remain in service “well beyond 2050.”
KC-46A Pegasus To Remain A Vital Part Of USAF
The US Air Force is increasing its KC-46 Pegasus tanker purchases, upgrading its fleet of KC-135s to remain in service well beyond 2050, and investigating options for a next-generation tanker. Boeing is to continue delivering KC-46s at least to 2030 and likely into the 2030s. They are set to become an ever-increasingly important part of the USAF aerial refueling capabilities.
Given that the oldest KC-135 is now 68 years old, the KC-46 Pegasus has a chance to remain in USAF service until around 2100. If the last Pegasus tanker were to live for that long and was to be delivered in 2030, then it wouldn’t retire until 2098.
Boeing is set to end commercial production of its 767-300F freighter in 2026 before new regulations come into force in 2027. Deliveries of the Boeing 767-300ER and 767-400ER ended years ago as it was superseded by the clean-sheet Boeing 787 Dreamliner. Still, the aircraft has managed to live on as a military tanker and is now the world’s second most common tanker after the KC-135.
