[Vehicles] Low-grav, high-pressure aircraft

[DataPacRat]

I'm toying with a setting resembling John Varley's "Gaea": a weirdly-living wheel-type space station, 1300 km in diameter and 250 km wide. ( http://ammonra.org/gaea/ has some nice pictures.) On the interior "surface", the centripetal acceleration is close enough to 0.2 gravities, and the pressure close enough to 2 atmospheres to just use those numbers.

Vehicles Expansion 2 gives a formula for stall speed in different gravities and pressures, and I'm guessing that in most Vehicles formulas, Loaded Weight refers to "GURPS Vehicles Weight" multiplied by the local gravity... but I'm not quite sure how I should adjust drag for pressure. Anyone know what math is involved?


(I plan to use a Hard Science/no-superscience lens, and a biotech-oriented untransistorized steampunk approach wherever feasible. Eg, making anything made of metal more expensive - probably a blanket x10 cost, without going into details of monopolies and imports. Similarly, hydrogen is going to be a lot cheaper than helium as a lifting gas; and if anyone does put together a combustion engine, alcohol's going to be a cheaper fuel than petro-products, given how easy it is to distill on demand. My first goal once I have the right formulas is to try to put together stats for an ornithopter for a SizeMod -1, ST 10 pilot, made of wood, using a muscle engine; and to try and get it as light as possible.)