On Wednesday, September 26, 2012 8:11:07 PM UTC-4, John Cochrane wrote:
On Sep 25, 11:29*pm, "kirk.stant" wrote: With all the new (and some of the older - SN10 for example) vario-computers having accelerometers and settings for ballast and polars, would it be possible to compute and display the optimum thermalling speed adjusted for wingloading and bank angle (as a function of instantaneous G-loading)? Since we don't (yet) have AOA gauges (which would do a better job of indicating the correct speed to fly in a thermal), I'm curious if a simple "speed to fly" indication would work. Obviously, filtering a constantly varying G-load would have to be employed, but I'm thinking of a 2-3 knot speed band display - using the same fast-slow indicator used for cruise speed control - preferably also with a deadbeat digital readout of the optimum speed to thermal for an average of the past 3 seconds or so of turn/averaged G. Would this work? Probably only once established in a steady, smooth turn - but that would give a good starting point for the next thermal. Kirk 66 I think it would work very nicely. Quick, if you normally thermal your ASW27 empty at 44 knots in a 30 degree bank, what's the right speed for 12 gals of water ballast each side? What's the right speed for 50 degrees? Accurate speed control makes a big difference. It's been on my (rather long) punch list of requests to the clearnav team for a while, if anyone else were asking they'd probably do it. John Cochrane

I would expect, for such a device to be effective, there would need to be quite a complex set of inputs, both from sailplane data, and sensory input.
Some examples:
1- Glider performance information for all likely flap settings used in thermalling.
2- Current mass
3- Knowledge of and the ability to quantify and input a variable for how the glider responds to horizontal and vertical gusts
4- Airspeed input, gust input- via asi , 3 axis accelerometers.
5- A harder one- what is the next gust going to be?
6- Others I'm not bright enough to think of now.

THEN- all the programmers need to do is whiz up an algorithym that takes all these into account and pops out "the number".
The vario folks are just now, 20 years after "the Dave Ellis dream", beginning to master the next level of variometry.

I'm not surprised that the ClearNav guys haven't bitten on this. It would be really hard to do in a meaningful way and maddenly difficult to try to explain to us glider jocks how to use it.
UH