A leading Chinese aerospace firm has filed a patent for a faster and more stable way to launch military drones that it says could help bring them into line with systems used by armed forces elsewhere. The new launch system uses air pressure to catapult a drone into flight without emitting light, sound or exhaust which – unlike using rocket boosters – keeps troops hidden from adversaries. That is according to a Chinese patent application from state-owned Avic Chengdu Aircraft Industrial Group, which was published last week. The company’s Wing Loong I and Wing Loong II medium-altitude long-endurance drones are the basis of the GJ-1 and GJ-2 armed reconnaissance drones used by China’s air force. Drones – or unmanned aerial vehicles (UAVs) – are used to observe, monitor and attack targets in battlefields without endangering personnel and are cheaper to produce and operate than conventional aircraft. “Achieving unmanned aerial vehicle catapults that can support high-mass and fast take-offs is a key problem that needs to be solved urgently,” the patent application reads. “Developing domestic UAV pneumatic catapult-assisted take-off equipment is an important development.” Avic Chengdu did not respond to a request for comment. Inside the catapult is a hollow cylinder that has a piston within it, effectively separating the cylinder into two chambers. The piston can slide horizontally along the cylinder, according to air pressure changes in the space on two sides of the piston. The piston is connected via a pulley system and a thrust arm to an external shuttle that travels along a launch rail, on which the drone is mounted. As high-pressure air enters one side of the piston and a vacuum pump lowers the air pressure on the other side, the piston will move horizontally and pull the shuttle from one end of the catapult to the other, propelling it into the air. “With the pulling of the thrust arm and the pulley system, the shuttle with the drone will move forward on the launch rack at a velocity several times quicker than the velocity of the piston,” according to the patent application. “Once the drone reaches launch speed, it will detach from the launch rack.” But that is not the end of the launch: the shuttle needs to return to its original position quickly to launch another drone. A cushion at the end of the rail softens the impact of the shuttle on the catapult, to prevent the force from damaging the launch rail. Valves controlling air pressure then open and close to balance the pressure in the two chambers. After at least five seconds for air pressure to normalise, the shuttle is pulled back to its place, ready for another drone to be mounted. The launcher’s creators said it could help China to develop a launch mechanism similar to those used by the armed forces of other countries such as the US, Britain and Switzerland. China’s military looks for new drones, intelligent vehicles for logistics But Zhou Chenming, a researcher from the Yuan Wang military science and technology think tank, said the significance of the patent should not be overstated. “Whether it’s useful, it remains to be seen,” he said, adding that ideas on such patents tend to sound reasonable on paper. However he said research into how drones could be used in battlefields was important because they will be “irreplaceable” in future warfare. The People’s Liberation Army uses drones to help China surveil islands contested with neighbours Japan and Taiwan in the South and East China seas, according to Hwang Won-june, an assistant professor who researches drones at the Korea Military Academy in Seoul. The PLA Navy’s active use of drones has also prompted Japan and South Korea to strengthen their drone capabilities. “What could be worrying is that the competitive development of UAVs in the region might trigger militarised interstate disputes or precarious arms race among these militarily advanced states around the East China Sea,” Hwang wrote in a 2020 paper. But Zhou said artificial intelligence technology used on drones and their singular design had left much room for military drone development, especially in the area of adapting to the complex and changing conditions of battlefields. “China and the US have comparable UAV technologies,” he said. “The US began earlier but China has a more complete system. Especially in the last five years, China is ahead of the US in using hypersonic drones.” China is also the leading exporter of armed drones. Those in Avic’s Wing Loong series have been sold to Egypt, Pakistan, Algeria and Saudi Arabia, according to data from the Stockholm International Peace Research Institute. From 2010 to 2021, Chinese arms manufacturers have exported at least 380 UAVs.