Yep Alan,

Last April, at the Brotherhood of the Ring Roundup in Houston, I (and many others) watched Dee Rice do about a half dozen lazy figure eights downwind with his Ringmaster after his engine (not an electric) stopped. He was able to whip it through those eights and I think the wind was acting on the RM much like a kite. The wind by the way was quite brisk and I, myself, re-kitted my electric Ringmaster when I lost line tension. Dee is quite an impressive flier but Joe Gilbert edged him out in the expert pattern competition.

Anyway, you may be right in thinking that the wind, when downwind, is giving an assist and thus some extra power.

Archie,
I have not yet uploaded the new firmware. Still plan to but haven't gotten around to it yet.

Jim,
Actually the power usage goes up going downwind, and eases off going upwind! The reason is as the plane turns into the downwind leg, its airspeed begins to drop. Yes the wind does try (via drag) to speed it up, but the main thing that happens is that the prop sees a heavier load---after all the rpm is being kept constant, but the airspeed has dropped, so the load goes up.
After it turns into the upwind leg, just the opposite happens, the airspeed increases, so the prop load decreases.

I was amazed by this when I was looking at the first few plots from my data recorder and was puzzled by how the battery current oscillated every lap, then even more surprised when I noticed when the highest current occurred--90 degrees before the downwind location we do the maneuvers, just when the plane has the highest tailwind.

So you can argue that some of the power savings comes from the fact that the higher power period is shorter (the groundspeed is highest) than the low power period (since the groundspeed is lowest). But I also think the peak power in the maneuvers is reduced since we are getting some energy for the climbs from the wind. I haven't run the data recorder recently to see if the peak power levels are reduced on a windy day, so this is a guess on my part--motivated by the people who can fly maneuvers with no power in the wind. Certainly can't do that (easily at least--I suppose you could whip) on a calm day!

Well, just a total off the cuff theory, if you were to hook up the static and live pressure sensors from the eagle tree data  recorder so they function as a pressure differential swithc, perhaps the static port on the forward portion of the wing, and the live on the aft. Then as the pressure changed going with the wind, you could use this information to activate a magic circuit ( the specifics are not in my realm of knowledge but easy enough to see how it could be done) this signal could make the apprpriate adjustment to the speed controller.

Based on what Alan is seeing, If I understand him right, the airframe as it comes around to fly downwind actually is feeling a slowing down *relative the the air mass* and is trying to accelerate to regain its relationship to the air mass, though at this po0int the ground speed would be already higher than normal lap speed.
hmm

Hi Gang,
The slight reduction in energy consumption in moderate runway air has been noticed so often that it is unquestionably true. Then again, I have been setting a click or two richer in the same air with my wet setups for years now ... there is nothing new under the sun.

later,
Dean