The Caihong-4, China's top-selling unmanned combat aircraft, will soon have a more powerful engine that is expected to greatly improve its operational capability, according to its maker.

The China Academy of Aerospace Aerodynamics in Beijing, a subsidiary of China Aerospace Science and Technology Corp, said in a news release on Wednesday that a prototype equipped with a new type of heavy-fuel piston engine has recently completed all required tests to verify the drone's autonomous takeoff and landing, load capacity, flight ceiling and radius, as well as other functions.

The successful completion of the test flights confirmed that the upgraded drone is ready for operational deployment. The new version can be deployed on plateaus and islands and will also prove useful in civilian operations such as providing a signal relay in emergencies, extinguishing forest fires and obtaining data for city authorities, the academy said.