at first i didnlt have a clue what you were on about, but now i think i see it. What you are seeing is the normal engine aperture but the nozzle is
set to its smallest diameter setting. This is giving a false impression of an extra hole which is not there. Perfectly normal photograph of a
perfectly normal formation of F-15's. No need for the 'photoshop fake' get out call here.
The engine cowlings are much bigger than the nozzle itself (when closed), and due to the perspective it looks as if the right cowling is a separate
engine.
When i looked at the F-15 with the ID. MO 380 I actually thought i saw 3 rear nozzles on that F-15. But after a closer look it was just the shadow
that played me a trick.
My first thought was! Man have they put the F-35 engine between the two original engines. Because initialy at first glans it did look like it lol.
ok everyone regardless it looks like there is 3 engine of course it is not by the comments above, but still kinda cool , i have heard things about
4 engine fighter/bomber that uses pulse detonation technology whether its true or no i dont know but there has been experimentation with the
technology