I've made a sheet cake with a jet on top. I wanted to wrap a fondant flag on and around the jet. I made the flag, but I think it's way to big and heavy. I really need something to cover what the jet is sittingon and maybe hide few of my mistakes....any ideas

I'm not sure what you mean by a jet on top, that cannot withstand the weight of the flag. Is the jet fondant, or piped on? Or is it an added figurine (since you are saying it is sitting on something.) Can you just make a smaller flag; roll the fondant thinner? What about piping on clouds over the base, for the jet to be soaring over? A blue field with white stars (if you don't want to hassle with trying to redo the whole flag?)

I agree with Cesehll-try doing some clouds if you don't want to re-do the whole flag. What kind of even is the cake for? A birthday? Is there another theme for the party that you could add in?