Aircraft Environment Limits

[Jeff Hopper]

The way the rule is written now with regards to atmosphere, an aircraft manufactured on a Standard atmosphere world (code 6) could fly on a Standard Tainted world (code 7) and a Thin atmosphere world (code 5), but not a Thin Tainted world (code 4). Since aerodynamics and lift are dependent on air pressure, this atmospheric code shorthand makes no sense. Atmospheric taint should not affect aerodynamics, although they will affect moving parts and electronics on exposed surfaces of the aircraft.

 

[Rikki Tikki Traveller]

I saw the same thing.

I have a Master's Degree in Aerospace Engineering. DENSITY is more important than "taint" for flying ability (assuming there is oxygen).

My suggestion:

Aircraft can only fly on worlds with Size within 1 of their world of creation and the same atmospheric pressure rating (Very Thin, Thin, Standard, Dense etc.)

NOTE: This would also change the example as the ATM would only be 6-7, not 6-8 as shown.
ALSO: Aircraft suffer DM-1 to all checks made to control them if they are within 1 of their home Size type. They suffer a DM-4 to all checks made to control them if they are within one pressure range of their home atmosphere (Thin to Standard or Thin to Very Thin) and cannot operate if they are 2 or more pressure types away from their home type (Very Thin to Standard or Thin to Dense)

 

[Tenacious-Techhunter]

I agree about the taint thing... it's irrelevant, and it's density that matters.

However, you lost me with the density limits.

Unless we're talking about a combustion engine airplane, in which case the density of available oxygen becomes an important issue, aircraft should be able to fly the same at the same Reynolds number, regardless of the available atmosphere. Limiting the issue to turbine and propeller craft, and Grav-craft without aerodynamic surfaces, since atmosphere means nothing to a Grav-craft except a speed limit, increased atmospheric density planets are only going to impose more limiting speed limits; both on the turbine and props, and on the craft itself, and at the same rate for both. So the thing will still fly, so long as it's fusion-powered... it'll just be really soupy and slow.

In less dense atmosphere, the biggest problem is getting going fast enough to reach the Reynolds Number at which your lift is higher than your weight. Which is an even bigger problem on unsettled wilderness low gravity worlds, because there's less gravity to flatten the terrain, and give you a nice smooth landing & takeoff strip at which to build up the necessary speed. So there, I agree with you again.