Optimum thermalling speed display

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

Since we don't (yet) have AOA gauges...
Kirk
66

If you want to buy one they are available. Check out www.safeflight.com
There are more listed on page 16 and 17 of the Feb 2008 issue of
Soaring.

Trying to thermal effectively while keeping your speed within a 2-3
knot range sounds
like trying to balance on a ball. I suspect the slight difference in
efficiency is not significant.

On 9/26/2012 9:49 AM, soartech wrote:

Since we don't (yet) have AOA gauges...
Kirk
66

If you want to buy one they are available. Check out www.safeflight.com
There are more listed on page 16 and 17 of the Feb 2008 issue of
Soaring.

Trying to thermal effectively while keeping your speed within a 2-3
knot range sounds
like trying to balance on a ball. I suspect the slight difference in
efficiency is not significant.

What many pilots need is a G meter that nags them to use a steeper bank
than the 20-30 degrees I often see. That would improve the their
climbing effectiveness a lot more than the optimum AOA.

--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to
email me)

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 have a ClearNav, love it but don't want to look at it that much.
Using "normally" and "30 degree bank" in the same sentence is a typo?
Jim

How about a bank angle read out on the new Butterfly vario so the guys that think they are flying a 45 degree bank can see they are really only banked 20 degrees? Not sure I need a speed to fly, usually it is as slow as the glider will fly well. Any slower it will mush or be slow on the controls, any faster and I am flying too big of circles. Too many different types of thermals for one number.

On Thursday, September 27, 2012 2:58:22 AM UTC-4, Tim Taylor wrote:
How about a bank angle read out on the new Butterfly vario so the guys that think they are flying a 45 degree bank can see they are really only banked 20 degrees? Not sure I need a speed to fly, usually it is as slow as the glider will fly well. Any slower it will mush or be slow on the controls, any faster and I am flying too big of circles. Too many different types of thermals for one number.

Every glider in the fleet has a handy 45 degree bank angle reference. Use your instrument screws. Kilobuck solutions not required.

T8

On Thursday, September 27, 2012 6:26:50 AM UTC-5, Evan Ludeman wrote:
On Thursday, September 27, 2012 2:58:22 AM UTC-4, Tim Taylor wrote:

How about a bank angle read out on the new Butterfly vario so the guys that think they are flying a 45 degree bank can see they are really only banked 20 degrees? Not sure I need a speed to fly, usually it is as slow as the glider will fly well. Any slower it will mush or be slow on the controls, any faster and I am flying too big of circles. Too many different types of thermals for one number.



Every glider in the fleet has a handy 45 degree bank angle reference. Use your instrument screws. Kilobuck solutions not required.



T8

Not sure how accurate this is, but an interesting experiment regardless...

http://www.stolaf.edu/people/hansonr/soaring/spd2fly/

On Thursday, September 27, 2012 6:26:50 AM UTC-5, Evan Ludeman wrote:
On Thursday, September 27, 2012 2:58:22 AM UTC-4, Tim Taylor wrote:

How about a bank angle read out on the new Butterfly vario so the guys that think they are flying a 45 degree bank can see they are really only banked 20 degrees? Not sure I need a speed to fly, usually it is as slow as the glider will fly well. Any slower it will mush or be slow on the controls, any faster and I am flying too big of circles. Too many different types of thermals for one number.



Every glider in the fleet has a handy 45 degree bank angle reference. Use your instrument screws. Kilobuck solutions not required.



T8

Evan, I think Tim's comment was tongue in cheek...
I agree with him, why the hell do you need a thermaling speed director, what happened to good-old hand flying the glider and taking pride in the results?

On Sep 27, 1:17*pm, wrote:
On Thursday, September 27, 2012 6:26:50 AM UTC-5, Evan Ludeman wrote:
On Thursday, September 27, 2012 2:58:22 AM UTC-4, Tim Taylor wrote:

How about a bank angle read out on the new Butterfly vario so the guys that think they are flying a 45 degree bank can see they are really only banked 20 degrees? *Not sure I need a speed to fly, usually it is as slow as the glider will fly well. Any slower it will mush or be slow on the controls, any faster and I am flying too big of circles. *Too many different types of thermals for one number.

Every glider in the fleet has a handy 45 degree bank angle reference. *Use your instrument screws. *Kilobuck solutions not required.

T8

Evan, I think Tim's comment was tongue in cheek...
I agree with him, why the hell do you need a thermaling speed director, what happened to good-old hand flying the glider and taking pride in the results?