China to start upgrading J-20 fighter engines in bid to close gap with US F-22
- A source says the jet, also known as the Mighty Dragon, will be fitted with thrust vector nozzles to improve performance
- The country has spent decades trying to master the technology and the upgrade comes after work on a purpose-built engine fell behind schedule

China will start upgrading the engines of its most advanced stealth fighter jet, the J-20, this year to bring its performance closer to the American F-22 Raptor, according to a military source.
The US Raptor uses the technology, which controls the direction of the engine thrust, allowing the jet to perform sudden manoeuvres that earlier generations of aircraft cannot.
Chinese engineers have been developing a high-thrust engine, known as the WS-15, to allow its most advanced fighter to close the gap with US warplanes.
But this project has fallen behind schedule, prompting its developer, the Chengdu Aircraft Industry Group, to use the WS-10C on the planes instead.
A source familiar with the engine development programme said all WS-10C engines fitted to J-20s will be given thrust vectoring capabilities this year.