That friend is my source but why in Karachi JF-17 had more smoke than the one in Islamabad even if it was old engine they did something to reduce smoke and also performance was much better than last year@Zarvan just to confirm, NO the JF17 at the 23 March parade where NOT with WS13. You sources/friends jut based that claim on an observation regarding how the engines produced lesser smoke. NO TRUTH IN THIS. I hope you will believe this and we wont be seeing this reference of new engine on every single tread. AGAIN, the JF 17 was carrying the same engine. Just to be extra sure, look at some of the pictures of the JF17 demonstration and observe the exhaust nozzles, you will realize (i hope so) that these are all same.
Because if you look at the pics you will see the nozzles are same.
I am not sure how else this is "myth" could have been debunked because it is a physical evidence. For sensible people, a logical evidence, like, JF17 is being test flown with WS13 and you do not bring 100% ready system for PUBLIC display with the world watching. Logical enough i guess. Now with physical evidence presented as well, i hope you can ask your "friend" about this and perhaps he can cook something up in haste.
I am looking forward to those happy days!!!
