7-24-11, I wonder if it really matter's what the true "meaning" of "speed" means to most of the pilots I've spoken to. I've given up asking "what is your airspeed..?" or "how fast is your airplane...?" because of the outlandish speeds given in spite of wind direction. It seems to matter little that their GPS units id this speed as "ground speed" or not. Speed always was understood to mean "AIRspeed" and any other speed was calculated from winds aloft and ID'd and spoken as "ground speed" and used for flight planning purposes. The handheld GPS units can only show actual ground speed while in flight for us now days, not much good for pre-flight planning, perhaps someday a whiz software writer will change that and write and "app" for the iFly. I often wonder if there are pilots using GPS speeds to prevent stalling especially in IMC...! Or when in flight vis is down to minimums...? Maybe the iFly "should" id the speed in big letters as "ground speed" for this reason, just in case there is someone mistakenly using a handheld GPS ground speed as "stall prevention speed " (air speed) while in IMC. I suspect GPS units so marked with ground speed (to keep error's down) are those that are certified and panel mounted and are used for IFR enroute reporting, but not for the pre-flight planning or the "approach" airspeeds. Must present a tricky "scan" with all these speeds to sort out while in IMC, glad I'm only flying VFR now. There may be units that are able to calculate true AS in spite of the AC altitude, but then their "speed" would be id'd as "AS" wouldn't they...? For all others it's ground speed...!