NANCHANG, Nov. 27, 2017 -- Three unmanned helicopters made test flights recently on the Qinghai-Tibet Plateau, authorities said Thursday.

The AV500W conducted firing tests at an altitude of 4,300 meters in Qinghai province on Nov 18, according to Jiangxi provincial office of science, technology and industry for national defence.

At 4,600 meters above sea level, on Nov 9, XM20 multi-rotor drone took off and landed with a full payload.

The AV500 climbed to an altitude of 5,006 meters during tests on Oct 31, the maximum achieved by a domestically-made unmanned helicopter.

The three have applications in counter-terrorism, drug policing, border patrols, meteorology and mapping.

The aircraft were developed by a helicopter research and development institute in Jingdezhen, Jiangxi province, owned by the Aviation Industry Corporation of China.

The institute began work on unmanned helicopters in 2004.