Following question about flight on other planets an answer contained a quote:
Jupiter: Flight on Jupiter is unrealistic. Jupiter's gravity is much too strong. The power required to maintain flight is about 3x that of Earth making flight there highly unrealistic.
Fighter jet planes use engines that are much more than 3x the power required for flight. Sure that's wasteful and expensive, but not nearly impossible.
Moreover, what is expensive in terms of energy, is rocket engine that contains its own fuel and oxidizer. On Earth we commonly use jet engines that use atmospheric oxygen for oxidizer, and own fuel.
Now, what if we reverse that? If the engine were to fly in hydrogen (or methane for that matter!) atmosphere, it would need its own oxidizer but it could burn the atmospheric gas for power... or am I missing something? Would an aerobot on Jupiter, Neptune or any of the planets with enough burnable material for an atmosphere, using own oxidizer to burn it for propulsion, be viable?