One of the most deadly aircraft is the F-35 and the F-22, but their Achilles heel is their range. That can be remedied by having stealth tankers to gas them up to extend operational ranges, but it might come in with a huge price tag.
Both the F-35 and F-22 as of now has limited range, and drop tanks cannot be taken without compromising stealth. Having these tankers for refueling will make them more effective with great range.
One advantage of conventional craft is that it can be loaded with extra drop tanks, but a modern stealth fighter profile will be ruined by extra shapes on the fuselage. Enemy radar will detect the shape and warn enemies even before reaching way-point, reported in National Interest.
Stealth fighters need a forward base or aircraft carriers that bring them within range of missiles. The need for staging bases place them on runways or a carrier deck that makes them sitting ducks. In missile barrage, there is no assurance that many airframes will survive, accoding to Yahoo News.
Most US jet fighters are capable of mid-air refueling, but these tankers need to stay clear of enemy planes. Unfortunately, they can be struck by Russian R-37, which can target from 250 miles away. One other danger is that non-stealth and stealth capable craft that can get past tankers in their sights. With tankers destroyed, most fighters are a disadvantage and will have nowhere to go.
Loss of refueling support will make it harder for F-35 to hurtle in, without the fuel gauge. Missiles like the SAM S-400m, another is the 40N6 missiles too.
KC-Z Next gen air tanker
Under procurement is the 179 units of KC-46A Pegasus tankers using the Boeing 767 airframe, which will take over the older fleet of 400 KC-135 and KC-10. Another tanker on the list is the conventional KC-Y due in 2024, and to follow is the KC-7 stealth tanker.
Defense News reported that getting the KC-Y might be scrapped in favor of improved KC-46 and getting into the KC-7 stealth tankers, with acquisition that starts in 2035. It was mentioned by General Carlton Everthart in 2016.
Initial designs for the stealth tanker (KC-7) is turning out to look like a 'Quinjet' from the avengers. One of the designs submitted by the Air Force Research Lab in 2018, that was called the 'Advanced Aerial Refueling' or a flying angled wing.
Another design by Lockheed called the 'Advanced Tanker Concept', that has flying wings which are more stealthy than other designs. One of the ways to reduce detection is redirecting the exhaust over the wings, cited in The Drive.
The Air Force is more interested in a 'Blended Wing Body'-type tanker with a triangular shape that merges the wings and fuselage seamlessly. Another aspect is a stealthy design that blunts detection by radar. Another is the C which means it can be cargo jets, it must be able to carry equipment.
It would not be the pure stealth wing design but also insert troops into the enemy's back yard that includes airborne refueling.
The think tank might want to put active protection systems for countering missiles that detect it. Adding next-generation radar jammers with AI to decide what to do. Less crew would be on board to let robots and automated systems do the tasks. Other options are using drones to refuel planes in the air.
A mix of manned and drone craft is considered by the air force, but getting survivable air tankers is needed to get F-35s and F-22s into range attack enemy territory.