I am trying to unlock the final plane in Big Boss mode. From what I have heard you need to be beyond the "Ultimate" rank in order for it to appear in the single player arena mode, however I cannot seem to get a higher rank. Does anyone have any tips or know how to unlock the final plane? Thx in advance for any help.

The plane I am trying to unlock is Premium Reward 6: F-15J Eagle "305th Squadron"


I found this online:

"To get Premium Reward 6, Unlock the other planes of your five wingmen. After this get the "Best Guy" or "Predator" rank in multi-player mode. When this is done, go to Challenge mode and select "Arena". Shoot down enough planes so you get the rank "Top Gun". After you get that rank, land and save. Go to Big Boss mode and the 305th Squadron. The F-15 should be available. "

One more question I have however is am I required to play multiplayer to achieve the "best guy" or "predator" ranks? Can I just achieve these ranks in "arena" under the Challenge mode? In other words, am I required to play online against real people in order to unlock the final plane?

Can anyone explain in detail how to unlock premium reward 6??? Thx again for any help.