Originally Posted by
Nortonious
Pretty good guess. The classic answer is 1 NM per 1,000 ft AGL (or 6:1 as you guessed). A completely clean jet is actually a little closer to 8.5:1, but it's best to err to the conservative for some non-jettisonable stores, etc cuz landing in a field is not really an option (the 16 is F-16 is not derived from any 4x4 capabilities).
As i recall sometimes the limiting factor is the hydrazine generator providing power? No gliding say 40 miles from 40,000 as the flight controls would quit operating before touchdown.