China's home-built J-20 stealth fighter has conducted sea training for the first time, the air force said Wednesday. The recent mission took the plane or planes out to sea for drills under "actual war conditions," air force spokesman senior colonel Shen Jinke posted to the service's microblog. He called that a "further upgrade of the air force's combat capabilities". China said in February that the plane had obtained initial operational capability and was being introduced into combat units. First flown in 2011, the J-20 is China's answer to fifth-generation jets such as the US F-22 and F-35. With its stealthy capabilities, speed and maneuverability, it potentially represents a major upgrade to Chinese air power, although questions have been raised about some of its technologies, especially its engines. <strong>_______________</strong> <strong>Read more:</strong> <strong><a href="https://www.thenational.ae/business/stealth-fighter-jet-test-is-china-s-latest-military-aircraft-endeavour-1.188555">Stealth fighter jet test is China’s latest military aircraft endeavour</a></strong> <strong><a href="https://www.thenational.ae/world/asia/china-continues-rise-in-military-spending-1.367227">China continues rise in military spending</a></strong> <strong>_______________</strong> Although developed domestically, the J-20 is believed to rely on Russian engines for propulsion. China increased its defence budget by 8.1 per cent this year to $173 billion, as it prepares to launch its second aircraft carrier and field an array of advanced warplanes and missiles able to attack air and sea targets at vast distances.