On Sunday, January 13, 2013 6:37:47 PM UTC, wrote:
We would have to get used to vertical tapes for speed and altitude

I don't have a fraction of the experience and background knowledge required to hold an opinion on this subject, but since that's never stopped me befo I wonder if tape indicators (specifically 'fixed pointer, moving tape' indicators) really make sense for gliders. I understand that they originated as mechanical displays in supersonic military aircraft of the 1960s and that the basic design has remained unchanged through moves to HUDs, then PFDs in transonic aircraft and finally trickled down into slower and slower aircraft.

Once we're into the performance range of gliders, it's not so useful having an indicator that focuses on a small working band of the airspeed and altitude range in order to give precise rate-of-change information. There are plenty of other cues the pilot uses to judge and control rate of change of airspeed, and the rate of change of altitude is something we modify our flight according to rather than manipulate with throttle, so the rate of change information is no great gain. I suspect that there's extra work required to read the instantaneous airspeed / altitude - in a situation where the pilot is under high workload or inattentive / complacent this could be a big drawback.

That's just my gut feeling though. I'd be interested in any studies of the benefits / drawbacks of tape displays in gliders and light powered aircraft..