TAS is great if you happen to be at sea level on a standard day. The rest of us have to deal with IAS. GPS speed at higher elevations really gives no indication of the aircraft's capabilities at sea level. To come up with a sea level equivalent performance number, I use a GPS number, then correct it for performance differences for wind, temperature and altitude. That will extrapolate a reasonably accurate performance number for documenting the aircraft performance, but is relatively meaningless to someone using their IAS to land the plane.
To me, the aircraft seems to approach and land painfully slow near sea level altitudes. And my landing speed at 7200' has me smoking past the traffic on the mph highway next to the airport. I'm usually still passing traffic on the highway next to me when the tail stops flying and the tailwheel sinks onto the runway. Searching for the key to the "Real" Pilot's lounge. ;o) -Jeff Scott Los Alamos, NM > > Joe Horton wrote: > > > First off I was just pondering the requirements to get into the "real > pilots" lounge.... > > Another point on IAS is that if your ASI is off on the low end, there's > often nothing that can be done about it. Mechanical gauges in > particular likely have that limitation, and even the iEFIS in my plane > lacks enough calibration points to deal with the low end adequately. > I'd venture to say that most airplanes are off by 5% or more on the low > end of the ASI scale. Mine's off way more than that. Cosine error of > the pitot tube's angle of attack could account for 3.5% of it at stall.
