Civilian planes landed on Subi and Mischief reefs for the first time on July 12, giving China three operational runways in the disputed Spratly Islands. Except for a brief visit by a military transport plane to Fiery Cross Reef earlier this year, there is no evidence that Beijing has deployed military aircraft to these outposts. But the rapid construction of reinforced hangars at all three features indicates that this is likely to change. Each of the three islets will soon have hangar space for 24 fighter-jets plus 3-4 larger planes.

The construction on Fiery Cross, Subi, and Mischief reefs follows a standard blueprint. The smallest and most numerous hangars are being built with four to six hangars per building. They can easily accommodate any fighter-jet in the People’s Liberation Army Air Force or Naval Aviation, including the J-11 and Su-30. The second type of hangar is large enough for the H-6 bomber and H-6U refueling tanker, Y-8 transport aircraft, and KJ200 Airborne Warning and Control System plane. The largest of the hangars can accommodate the largest planes in the Chinese fleet — the Y-20 and Il-76 transport planes, Il-78 refueling tanker, and KJ-2000 surveillance aircraft.

Fiery Cross Reef

Construction of fighter-jet hangars appears complete at the southern end of the runway and is well-advanced along the middle of the airstrip. At the northern end, construction on a final set of hangars is still in the early stages. Two medium hangars and one large hangar are being constructed toward the southern end of the runway.

Subi Reef

Most of the hangars are being constructed at the southern end of the runway, with a few small hangars at the northern end. All the fighter-jet hangars appear nearly complete. Two medium hangars and two large hangars are being built behind those for fighters at the south end of the airstrip, and will presumably be connected to the runway by an additional taxiway.

Mischief Reef

Construction of hangars at Mischief Reef is at an earlier stage. Small hangars are being built along the length of the runway, while three medium hangars and one large hangar are being constructed along the apron at its northern end.

Other Developments

In addition to the rapid construction of hangars and other air support infrastructure at Fiery Cross, Subi, and Mischief reefs, other facilities have appeared on the features in recent months. Unidentified hexagonal structures are quickly being built at four locations on each islet—always oriented toward the sea. Work on these structures began in May at Fiery Cross and in July at Subi and Mischief. Each of the features is also now home to a set of three towers, one of which is larger than the other two. The towers do not have domes that would indicate radar or other sensitive arrays, and their location is not consistent, at least in relation to the runway or other infrastructure, across the three islets. These structures do not appear at any of China’s other outposts in the Paracels or Spratlys.

Unknown Hexagonal Structures

Unknown Tower Structures