In a f16, take off and ascend to 40,000'. Travel back towards the earth at a 25 degree angel until your air speed hits 1,200 (it will read just 200 because it resets to zero at 999) Pull up as hard as possible to go back up, at this point, if done correctly and you pulled up as hard as possible, the f16 will continue to pick up speed at a very fast rate (I think my fastest speed was close to or around 6000 if I counted the resets to zero correctly.