MELBOURNE, Australia — Satellite imagery appears to indicate China has begun serial production of a tanker aircraft based on its indigenous Xi’an Y-20 airlifter, filling a notable gap in the power projection capabilities of its air force.

The overhead imagery of the airfield at Xi’an-Yanliang — taken Dec. 30, 2020, and provided to Defense News by Planet Labs — shows four Y-20s with the shadows of refueling pods on their outer wings clearly visible, indicating that these are Y-20U tankers.

The Y-20U is a tanker variant of the Y-20 and is believed to be fitted with three refueling points, these being located on pods mounted on the outer wings and one more on the rear fuselage.

Refueling is achieved by the hose and drogue method, with a refueling basket at the end of a retractable hose where receiver aircraft with inflight refueling probes “plug” into the basket before taking on fuel.

The first Y-20U prototype made its maiden flight in 2018, and the appearance of four Y-20U suggests the flight test program is complete or has advanced sufficiently enough for serial production to begin. It is unknown whether the Y-20U will be a dedicated tanker or will retain its cargo capability of the standard Y-20 airlifter.

The four-engine-strong Y-20 and Y-20U are still, however, powered by the Russian Soloviev D-30KP-2 turbofan engines. China is developing the WS-20 high-bypass turbofan for the Y-20 family, although the engine is not expected to enter production before 2024.

Three of the four aircraft in the satellite photo are painted in dark gray, while the last aircraft is still in its primer coat. One of the gray aircraft is the prototype, or test bed aircraft, while the other three are likely to be production aircraft.

The four Y-20Us are among 16 Y-20s seen throughout the airfield. Xi’an-Yanliang is where the production facilities of the Xi’an Aircraft Company, or XAC, is located, along with a number of aviation technology companies and research facilities.

It is also home to the China Flight Test Establishment, which is responsible for overseeing flight testing of new aircraft types built by Chinese companies.

Where does China’s refueling capability stand?

The Chinese People’s Liberation Army Air Force, or PLAAF, currently operates about two dozen tanker aircraft. That fleet is mostly made up of H-6U and naval H-6DU tankers based on the Xi’an H-6 bomber, which is itself similar to Russia’s Tupolev Tu-16, which dates back to the Soviet-era of the 1950s.

The PLAAF also operates three Ilyushin Il-78MP tankers acquired from Ukraine and delivered in 2014. The service has encountered issues with securing more of the Russian-built Il-76s airlifters for conversion into tankers or to boost its modest heavy airlift capabilities prior to the Y-20 entering service in 2016.

The small number of Il-78s in PLAAF service, as well as the limited fuel offload capability of the H-6 compared to larger aircraft, means China has what could be described as a modest inflight refueling capability.

This shortfall in tanker capacity is likely to ease if more Y-20Us are built, and the increase in the number of these force multiplier aircraft will enable China to extend its reach in airspace and keep its combat aircraft in the air for longer periods of time.

Mike Yeo is the Asia correspondent for Defense News.

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