Bradley Perrett Zhuhai, China

While the main mission of China's aerospace plants is to supply the military, they are also under pressure to make money where they can.

For managers and engineers skilled in aeronautics, that often means devising aircraft that might be sold in foreign markets or to domestic civil operators.

Lately, the most eye-catching example of that has been the so-called J-31 stealth fighter, which the Shenyang plant of combat aircraft specialist Avic Aviation Techniques presented at Airshow China in Zhuhai this month as an export product (AW&ST Nov. 19, p. 26). But in a nearby exhibition hall, national space contractor CASC revealed a medium-altitude, long-endurance UAV toting bombs and surface-to-air missiles.

At first sight the aircraft, the CH-4, looks like the Chinese military's answer to the General Atomics MQ-9 Reaper. But while CASC has developed an armed version of the CH-4, the aircraft is basically a surveillance airplane for civil use, say program officials. Indeed, they recognize a drawback in offering the CH-4 with weapons: Foreign governments may be less keen to allow airspace access to an aircraft that, for all they know, could be armed. For the same reason, some U.S. officials expect that no version of the Northrop Grumman RQ-4 Global Hawk, now used for surveillance by the U.S. Air Force, will ever be armed.

Unlike Avic Aviation Techniques, which is working on combat drones, CASC's unmanned-aircraft specialist, the China Academy of Aerospace Aerodynamics in Beijing, concentrates on surveillance types. The CH-4, fairly clearly, was not developed under a military contract, because the group has publicly exhibited it while it is still new.

The CH-4 is the largest unmanned aircraft that the group has revealed, with a span of 18 meters (59.1 ft.) and, in the heavier and armed CH-4B, a gross weight of 1.33 metric tons (2,930 lb.). The Reaper is much larger, with a gross weight of 4.76 tons.

Current sensors include a synthetic-aperture radar with a rotating antenna in a ventral radome and electro-optical and infrared cameras in a ball turret. The academy is working on integrating gravitational and magnetic sensors suitable for geological surveying. Developing an electronic system capable of working with many sensor types was the most difficult part of the program, says a designer.