China’s most advanced stealth fighter the J-20 narrowly avoided a “serious accident” in a test flight nine years ago during the early days of the aircraft’s development, according to its manufacturer. Aviation Industry Corporation of China (Avic) said the incident occurred on December 18, 2012, as one of the aircraft was taxiing on a runway, taxiing at high speed. The cockpit panel readings were green but ground data sensors sounded a warning and ground control ordered the test to be aborted immediately, just three minutes into the procedure. “According to retro analysis, had the order been 2 to 3 minutes later, a major accident could have occurred,” Avic said on its social media account on Wednesday to mark the 11th anniversary of the plane’s maiden flight. The Chengdu J-20 is the third fifth-generation stealth fighter in service in the world and a key element of China’s ambitions to modernise its military and draw level with other major powers. But it was not easy leapfrogging some of the most advanced technologies. Another J-20 plane fault was reported during a test flight on May 17, 2016, Avic said. During that incident, monitoring software sounded a warning, and ground control and engineers guided the pilot to resolve the problem and return safely to ground. Avic did not specify the nature of these events, saying only that during the test flights the team also discovered “many other severe load conditions that were not expected in the design stages”, such as overloading of hinged sections of the wings and uncommanded uplift of the aircraft. The J-20 made an unannounced maiden flight on January 11, 2011, the same day as then US secretary of defence Robert Gates met then Chinese president Hu Jintao in Beijing. Hu assured Gates the timing was little more than coincidence. Pilot Li Gang, who carried out this flight, was later awarded the Gold Medal of Honour for Meritorious Pilots, one of the highest honours of the PLA Air Force. The aircraft went through thousands of tests and subsequent modifications, including a test in 2016 on “the world’s highest airfield for fixed-wing aircraft”, a possible reference to Daocheng Yading Airport, which is 4,411m (14,472 feet) above sea level. The aircraft finally entered service in 2017. Some of the changes were to ensure the aircraft’s performance at high altitudes, with a couple of J-20s forward deployed at the Karakorum and Himalayan borders during a military stand-off with India in 2020, confronting India’s newly bought Dassault Rafales from France. The 2011 launch of the J-20 came just six years after the introduction of the fourth-generation Chengdu J-10 fighter. Many observers were shocked at China’s ability to present so quickly a stealth aircraft with supersonic cruise capabilities, super manoeuvrability and super avionics.