In 1997, the KA-6D Intruder tanker aircraft disappeared from the US Navy aircraft carriers - it was removed from service, and a full replacement was not provided. For this purpose, the F / A-18 Super Hornet fighters were adapted, which instead of weapons received external fuel tanks. Of course, this was inconvenient both for operational reasons (up to 30% of aircraft were forced to perform functions unusual for them) and for economic reasons (such Hornets did not have a special fuel capacity). It is for this reason that the leadership of the Navy was so eager to get a more efficient machine, of course, in the now fashionable unmanned configuration. In the very near future, United States aircraft carriers will use F-35C aircraft (paired with Super Hornets) with an effective range of no more than 1110 km. Naturally, in order to increase the combat radius of the use of such weapons, it is necessary to refuel in the air. This is how the CBARS (Carrier Based Aerial Refueling System) program appeared to develop a deck-based unmanned refueling vehicle.
A bit of a paradoxical situation, isn't it? The very unmanned ideology is aimed primarily at reducing the loss of personnel from enemy fire. A pilot on an airplane is the most valuable thing, and the loss of a highly qualified pilot is not only a tragedy in human terms, but also a tangible blow to the combat capability of the formation. At the same time, the Americans assign shock and reconnaissance functions to manned vehicles such as F-35C and F / A-18E / F, and a secondary tanker, which most often will not even enter the affected area, suddenly becomes unmanned. Why is that? All because of the unsuccessful UCLASS program, during which the shock X-47B was developed. At the beginning of 2016, the realization came that the vehicle did not meet all the requirements, and so far manned vehicles are much more successful in coping with the tasks of air combat. And the visibility of potential enemies on the radar screens of the X-47B was too high.
X-47B from Northrop Grumman - a failed attack and reconnaissance drone project for the Navy
This, by the way, played into the hands of Lockheed Martin - the Pentagon, disappointed in remote-controlled toys, accelerated the purchase of a deck version of the F-35C. But for the billions spent on unmanned shock "invisibility" it is necessary to somehow account to the taxpayers. And then the idea of creating an unmanned tanker was born, and even based on Stealth technologies. It is worth noting that under the new program, the requirements for stealth have become not so stringent - after all, the device has secondary functions and will not be used in the area of the alleged defeat. The new project received the code RAQ-25 "Stingray" and required another multi-billion dollar investment.
$ 3.6 billion
For the development of $ 3.6 billion under the MQ-25 program, a competition was organized in which the whales of the US defense complex - General Atomics, Skunk Works (a division of Lockheed Martin Corporation), Boeing and Northrop Grumman Corporation - took part. The Pentagon put forward demands to the contestants to prepare a ready-made technology demonstrator no later than August 2018. Initially, among the requirements for the new machine was the possibility of sea reconnaissance with the allocation of appropriate volumes for equipment inside the fuselage. But already in 2015, the defense department realized that it would be problematic to create a fairly compact tanker, and even with intelligence functions. Therefore, only a modest flying tanker remained.
What did the participants of the tender offer to the state? Northrop Grumman tried to convert its long-suffering attack X-47B into a tanker, but nothing sensible came out, and the corporation refused the competition. Lockheed Martin, represented by Skunk Works, developed a new aircraft with a flying wing design, which freed up a lot of space for the fuel tanks of the winged tanker. True, the presented car did not learn to fly by August 2018. And the very concept of the car was too revolutionary for implementation on a deck tanker. General Atomics took the new work seriously and unveiled a drone powered by the latest PW815 turbojet engine, making it the most fuel efficient in its class. The company has extensive experience in the field of building shock and reconnaissance UAVs for the US Army (MQ-9 Reaper, MQ-1 Predator and others), but the office is not very familiar with the specifics of the Navy, and General Atomics has never developed such large machines before. As a platform for the future tanker, they presented a modification of the Sea Avenger, an unsuccessful deck attack UAV, and in many respects overlapped the requirements of the Navy. However, despite the confidence of the guys from General Atomics in their victory, in August 2018, engineers from the Phantom Works of the division of the aviation giant Boeing turned out to be the winner of the tender.
Having presented the project of a heavy deck tanker based on the Sea Avenger drone, specialists from General Atomics were confident of victory. But it didn't work out …
One of the main advantages of the aircraft from Phantom Works is integration into the onboard systems of aircraft carriers. In fact, the maintenance team doesn't have to retrain too much when using the new product - many of the technical solutions came from the Super Hornet. In particular, the nose and main landing gear were taken from the Shershen with minor modifications. In total, the aircraft can take 6,800 liters of fuel on board and provide 4-6 aircraft with kerosene at a distance of up to 800 km. Among the main recipients of the tanker are the mentioned F-35C, F / A-17 and the EA-18G Growler electronic warfare aircraft. The aircraft is built according to the classical scheme with a normal sweep wing.
If all goes well, this particular vehicle will become the world's first unmanned deck-based tanker MQ-25 Stingray.
The specific appearance of the drone is given by the V-shaped tail, located at an angle of 60 degrees. Yaw and pitch control is obviously carried out by changing the direction of the flow of the jet stream of the engine. The engine air intake is located on top of the fuselage behind the gargrotto (protruding element of the fuselage skin). In the bow you can see another small air intake, which is obviously intended for cooling the on-board electronics. The MQ-25 Stingray is supposed to be equipped with one Rolls-Royce AE3007 turbofan engine, which accelerates the flying tanker to 620 km / h. The maximum take-off weight reaches 20 tons, of which about 13-14 tons are fuel. According to the requirements of the Pentagon, unmanned vehicles MQ-25 Stingray should be in a state of operational readiness by 2026. The first machines for full-fledged military tests are supposed to be created in metal in 2020-2021. In total, if the whole story at Boeing succeeds, the Navy will order at least 72 flying tankers.
In fact, a much less sophisticated flying tanker was born out of a failed reconnaissance deck drone program. It can be assumed that the technologies tested on the new product in five to six years will form the basis of the Pentagon's second attempt to create a strike vehicle for aircraft carriers.