We know China has been fairly conservative in the past when it comes to integrating new technologies, and this brings me to the subject of IEP. If China remains true to practice, it will want to validate IEP on 054B before integrating it on 055. This in turn suggests that 055 is quite some time away, i.e. early 2020s, or that we will see something like the 054/054A transition, i.e. only a couple of units before switching to an improved variant, itself occasioning significant delay. The third possibility is that they will proceed with IEP on 055 without prior validation on 054B.
Any thoughts?