Board Thread:Questions and Answers/@comment-25033368-20140618201722/@comment-25019843-20140618213334

Beerninja88 wrote: Sometimes the game lets me bet extra fuel and sometimes the option doesn't show up at all? Is there some kind of determining factor that makes betting available or is it totally random?

thanks Do you meant forced sorties? They come only in the weekends, from Firday to end of Sunday for 72 hours.

http://acecombat.wikia.com/wiki/Sortie_Fuel

Scroll at the bottom to see Forced Sorties.