China Surges J-20 Stealth Fighter Development at end of 2014

In November and December 2014 two additional prototypes of the Chengdu Aircraft Corporation's (CAC) J-20 fifth-generation fighter emerged, advancing its development towards a possible initial operational capability (IOC) of 2017-18.

The J-20 programme currently features six known prototypes. Two are early technology development articles (serial numbers 2001 and 2002) that emerged in 2009 and 2010, while four are modified versions closer to operational prototypes (serial numbers 2011, 2012, 2013, and 2015) that all emerged in 2014.

No prototype numbered 2014 has yet to appear and may not, given the traditional Chinese view that four is an unlucky number.

link.