According to reports, the development of the YY-20B tanker aircraft was carried out by specialists from the Xi'an Aircraft Manufacturing Enterprise of the Chinese Aviation Industrial Corporation by the beginning of 2019. The designers managed to strengthen and at the same time lighten the wing of the aircraft, improve the mechanisms of the flaps and slats (as well as increase their area), which increased the maneuverability of the aircraft over the entire range of heights and speeds.
The reinforcement of the wing structure is due to the placement of a heavier engine under the designation WS-20, which surpasses the Russian D-30KP-2 in most technical parameters, but is comparable to the PD-90A2. PLA Air Force test pilots noted an increase in controllability when flying at low altitudes and in mountainous terrain.
Serial transport aircraft Yun-20A (flight number 20842).
The maximum speed in horizontal flight will be 920 km/h. At full load, the flight range reaches 9,000 km, and at 80% load, the aircraft can fly at a range of 10,000 km. At 60% load, it's already 11,000 km.
It is known that to test the systems of the Y-20B transport aircraft, an experimental aircraft was manufactured under the number 781 "black" (photo 2), and an aircraft with the number 781-2 "black" was assembled to test the functioning of the tanker aircraft systems (photo 3).
F2. Experimental transport aircraft Y-20B
F3. Experimental tanker aircraft YY-20B
According to available information, flight tests of the tanker aircraft took place during 2021 and 2022, which allowed Chinese aircraft manufacturers to test the possibility of refueling in the altitude range from 9,000 to 13,000 m (with an interval of 1,000 m) for aircraft such as:
- fighter models J-11B, J-11BG, J-20, 20A;
- H-6N bombers
- long-range radar surveillance, guidance and control aircraft KJ-3000 and KJ-500A.
It should be noted that refueling in the air has been worked out both in horizontal flight and when performing left turns and heading adjustments.
During the control and test refueling, it was found that the fuel supply rate from the tanker aircraft to the second aircraft depends on the flight altitude. It is well known that universal suspended refueling units located under the wing consoles have a capacity of 2,200 to 2,500 liters per minute, while the refueling unit located in the rear fuselage can pump up to 4,400 liters per minute. The total mass of fuel that the YY-20B can transfer to other aircraft is 100 tons.
Theoretical calculations show that using modern materials, the hose-cone refueling system allows pumping up to 6,500 liters per minute, but the fighter fuel system does not allow taking more than 4,000 liters per minute.
As part of the training of the crews of tactical air refueling aircraft in the air, it was found that no more than 55 minutes is needed to replenish the fuel reserves of the squadron consisting of 9 J-11BG fighters, taking into account the fighter's approach to the tanker aircraft, receiving fuel and departing.
As of November 1, 2025, the Xi'an Aircraft Manufacturing Company has assembled 11 production tanker aircraft of the YY-20B model. The first five vehicles entered service with the 37th Division of Military Transport Aviation of the PLA Air Force (Kaifeng, Henan).
Taking into account the needs of the PLA Air Force to conduct air operations at a distance of more than 1,000 km from home airfields, military transport aviation units should have at least 75 tanker aircraft by 2029, of which 25 units will be YY-20A and another 50 units will be YY-20B.
Source: Chinese specialized publications
