Curtis L. Olson wrote: > 1. FlightGear has a property called /velocities/airspeed-kt; does anyone > know if this was originally intended to be VCAS, VIAS, VTAS, or what? > > 2. The pitot system uses /velocities/airspeed-kt as it's input (and > seems to assume this value is VIAS.)
This value looks like IAS to me. It's set from YASim via the FGInterface::_set_V_calibrated_kts() function. Note that the difference between IAS and CAS are due solely to gauge/pitot system issues. As far as the FDMs are concerned, they mean exactly the same thing. There is also an "equivalent airspeed" value that comes out, which is CAS without the mach corrections. I have no idea if this ever makes it to the property system, but FGInterface has a slot for it. A true TAS value* comes out via _set_V_rel_wind(), but I'm not sure where this ends up in properties. * Er... sorta. This is total airspeed velocity magnitude, whereas the pitot would really only measure velocity along its axis... If your suggestion is that we chuck all of this stuff and just pick some standard output props for the FDMs to fill out, then I agree. :) Andy _______________________________________________ Flightgear-devel mailing list Flightgear-devel@flightgear.org http://mail.flightgear.org/mailman/listinfo/flightgear-devel 2f585eeea02e2c79d7b1d8c4963bae2d
