Ok if you want 2 fly without a helicopter here is what you do first. Do the floating car cheat (proberly listed some where on this page)then the tank cheat (also proberly listed on this page) then turn its gun backwards.once u get in the air dont stop shooting its cannon and u should be able to fly. It takes a while 2 get used 2 but after a while it is very handy getting arround
P.S Good luck with the game :-)