The latest Chinese fighter jet turbofan engine, the WS-15, has flown on the Chinese J-20 stealth fighter for the first time. A new video shows that the J-20 with two new indigenously developed WS-15 engines took off from factory airfield and completed first flight. The WS-15 is similar to the F119 engine in the F-22 fighter. The J-20 fleet had been using Russian AL-31 and Chinese WS-10 engines. Comparing with the older engines, the WS-15 has zigzag exhaust nozzle edges. The WS-15 reportedly started development in the 1990s. The engine produces at least 36,000 pounds and will improve in future. The thrust to weight ratio is around 10, close to the American F119. This brings the J-20 10 to 20 percent more thrust. It is believed the latest J-20B variant has not adopted the WS-15 yet, but it will soon.