Record Attempt and 100K pin-Pioche, NV - RC Groups
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Aug 14, 2017, 11:49 PM
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Record Attempt and 100K pin-Pioche, NV


Last week a few of us (Dean Gradwell, Rick Shelby, John Ellias, Marquita Ellias, Bill Chase, and Barry Danieli ) went out to Pioche, Nevada to have some fun flights, try for 100k pin, and make a new distance record attempt.

Bill Chase wanted to get his 100K pin. Barry would be driving but they would have no spotter, making things a bit more challenging for Bill. Bill would be flying his Appersonic. Bill designed and built the Appersonic himself. The design is quite different from any other XC glider I know of. It has a long span very high aspect ratio wing. The wingspan is something like 4.8 meters with a chord of only 8 inches. Wing loading at 5kg is 22oz/sq. ft.

If the weather conditions looked ideal I planned to declare Twin Falls, Idaho as the goal, some 310 miles due North. Once Rick gave me his weather prediction of lighter wind and possible rain, I decided to declare Wells, Nevada as the goal, a total of 215 miles.

Forecast weather for pretty much the whole time we would be out there called for moderate southwest wind in the south, while to the north lighter wind and varying in direction starting at about 150 miles North of the launch location. Thunderstorms and rain were predicted for the Northern section of the course. As in past years we launched at an old abandoned airstrip just North of the town of Pioche, NV.

Wednesday we flew 108 miles and then ran into rain which killed the lift. Bill Chase launched a few minutes after us and flew into the same storm a little further South. He flew about 80 miles that day, more than enough to earn his 100k pin. They did have some trouble out on course when the Appersonic got too high and went into a dive (very easy to happen when have no spotter!). Bill pulled the flaps and was able to regain visual, but unknown to him at the time, both flap servos were destroyed during this maneuver. Only when he came into to land out did he realize he had no flaps! Despite this Bill managed to land OK. Unfortunately he was not able to replace the damaged servos, so he was not able to attempt any other long flights. Bill becomes the 14th pilot to achieve his 100K pin.

Thursday was very similar weather and we did 98 miles before the rain got us.


Friday the weather was a little drier. We got on course by 9:15 which was a little earlier than before. We managed sneak through the overdeveloped area just before the clouds closed in behind us. At this point the lift became quite strong (as was the sink), up to 1000fpm both up and down! We were going great, biggest issue was the crosswind, but we were able to deal with it. At about the 120 mile mark we had to transition to a secondary dirt road. All the rain in the area caused numerous washouts which required us to slow down to just a few miles an hour at those locations. Staring up at the glider while bouncing over the ruts made my head want to explode! Fortunately the lift was good and the areas of sink were small and not too severe in this area. Finally our dirt road intersected with Hiway 93A. Due to the lighter winds than last year the dreaded "backtrack" where the 93A runs Southwest into the 93 going North was not too difficult and we safely made it to HI way 93. Now things were looking really good. Our average speed was noticeably increasing. We speed through the sink as fast as the jeep would allow us to go, trusting there would be another thermal out there. We were always able to make to the next thermal. In many cases we were able to use the clouds to identify area of lift. It seemed the very young just developing Cuís signaled the best areas to find the lift. We had gone 180 miles and I was feeling very confident we would make the 215 mile goal. Then we see a sign "Road Construction Ahead, Expect delays up 30 minutes".

As we approached the construction zone there were cars backed up for quite a distance and as luck would have it the glider was now in very strong sink. We stopped in the traffic back up and I had nowhere to go to get out of the sink. I lost 3200' in 5 minutes! It was only 3:30 pm when we landed. 6 hours and ten minutes, 183 miles total. As is typical of the terrain out there the landscape is completely covered with desert scrub and sagebrush, not good for landing out. I elected to land on the shoulder of the highway, even though the road was lined with cars waiting for the construction to clear. It must have looked rather strange to see this glider come out of nowhere and glide right next to the line of cars. Unfortunately as the X2xc was sliding along the ground it hit a survey stake and put a large gash in the center panel. Very frustrating to have come that far only to be only to fall a mere 32 miles short of the goal.

Despite not making a new record it was quite an adventure and a lot of fun. We plan to do it again next year and hope more teams will join us.

One last note, Gary Fogel, David Hall, John McNeil, and Christopher Silva set what will be new Goal and Return record for electric powered RC aircraft. Gary launched in Pioche and flew approximately 70 miles North and then back to Pioche for a total of 140 miles. It seems the Pioche area is getting popular! Congratulations Gary and Team.
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Aug 15, 2017, 11:08 AM
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parajared's Avatar
Congrats,
Sorry to hear about you guys getting held up by road construction. 180 miles is pretty impressive, I thought the world record was in the ballpark of 200 miles.
Aug 15, 2017, 01:05 PM
Sagitta Fanboy
World Record is 187 miles (301km) from last year IIRC. It's a pity that construction stopped the 215 mile attempt, as that would have been a new record. As it is, you almost matched the current record.
Aug 15, 2017, 03:12 PM
Registered User
Thanks John,

For the detailed write up.
It's great to hear about the flights made.

Being stopped by road construction had to be really frustrating. Congratulations on the distance you did get.

Mike
Aug 15, 2017, 04:51 PM
Registered User
Congratulations Bill,

On the 100k pin and your 80+ mile flight.

That's an amazing accomplishment and has to
be especially gratifying to do so with a glider you designed and built.

Mike
Aug 16, 2017, 03:22 PM
Skye Malcolm, LSF Secretary
skye8070's Avatar
Thanks for sharing this great write up! For us Midwest and East coasters these distances are really staggering to think about. But a 1/4 century ago I rode across Nevada on highway 50 so I have an inkling. Just the sheer brutally on your eyesight must be immense. How long in time were you flying?
Aug 16, 2017, 04:04 PM
Registered User
Truly amazing. Wed.- 108 miles, Thur. - 98 miles, Fri. - 183 miles. John flew 389 miles in three back to back days.
Can't wait for next year.

Dean
Aug 17, 2017, 12:23 PM
yyz
yyz
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yyz's Avatar
Ditto. Great writeup as always John.

Quote:
Originally Posted by ThermalSeeker
Thanks John,

For the detailed write up.
It's great to hear about the flights made.

Being stopped by road construction had to be really frustrating. Congratulations on the distance you did get.

Mike
Aug 17, 2017, 07:13 PM
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TrekBiker's Avatar
great report John,

Bill and I have been talking about this and might be joining up with our team next summer. Good to hear Bill Chase made his 100K. I think he's used up about 8 of the 9 lives on his Appersonic!

Steve
Aug 18, 2017, 07:25 AM
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Gratter's Avatar
So do you think the high aspect wing design was the way to go for cross country?
Aug 19, 2017, 10:55 AM
Bro
Bro
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Bro's Avatar

Record Attempt


Hey guys,

Very cool stuff!! Nice work John!!

Best,
Bob
Latest blog entry: 2015
Aug 20, 2017, 11:23 PM
Registered User
Quote:
Originally Posted by Gratter
So do you think the high aspect wing design was the way to go for cross country?
There is no simple answer to that question. The best analysis I have seen was done by Greg Norsworthy (https://www.rcgroups.com/forums/show...ies-Giant-Icon)

I have flown a lot of miles on both the MXC (Large Wing area, low aspect ratio, low wing loading) and my Xplorer 2 (small wing area, medium aspect ratio, high wing loading). I can tell you this: I would prefer to fly my Xplorer 2 in almost any conditions or XC task rather than my MXC. The only possible conditions I might prefer the MXC would be in extremely light lift (100 ft/min or less). Conditions like that rarely last all day. Even then I would simply remove the ballast from the Xplorer which would result in a wing loading less than the MXC. However, I have never flown my Xplorer in competition or for a record with anything less than full ballast.

The Appersonic design by Bill Chase not only has a much higher aspect ratio than the Xplorer, but it also has a higher wing loading. I think this design has certain benefits; The high wing loading should help performance at higher speeds, while the high aspect ratio (long span) should help performance at lower speeds (thermaling). In other words it should have good performance over a wide range of speeds. There are a few drawbacks, the biggest of which is reduced visibility due to the narrow chord. That is a significant drawback.

Most of the time I wish my Xplorer had a higher wing loading. So what is the optimum way to increase the wing loading (assuming you maintain the max 5kg weight limit)? Is it be better to reduce the chord (increase aspect ratio) or decrease span and leave the chord the same? I don't know!
Last edited by XC soaringpilot; Aug 20, 2017 at 11:26 PM. Reason: spelling
Aug 21, 2017, 11:11 AM
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TrekBiker's Avatar
>So what is the optimum way to increase the wing loading (assuming you maintain the max 5kg weight limit)? Is it be better to reduce the chord (increase aspect ratio) or decrease span and leave the chord the same?

This is a good question and it has been interesting to watch the transition to the "J" planes with their superior wings and higher loadings these last few years. I remember the debate over visibility/height vs. speed/efficiency a few years back. I think everyone is pretty much in agreement that chord is more important than span for visibility. That said, its looking like Dr. Drela was right. We don't need to fly so high and the 12" minimum chord we all argued for visibility was not optimum given the 5kg max weight limitation and the resulting lower max wing loading. In an effort to maximize visibility with the larger chord, large area wings we were limiting our wing loadings to a max of around 15-16 oz to stay within the 5kg max allowed weight. But honestly, that seemed like a pretty heavy loading for a sailplane at the time. Also we were mostly flying distance tasks and now its pretty much shorter duration speed tasks and actual racing.

Wing loading and high L/D at speed seems to be the key for best overall racing performance. SuperCon (modified Icon2) is at 19oz. X2xc is at 20oz. Not sure what Appersonic is but I think 21oz. The highest wing loading so far and best performance I've seen was Philip Kolb's Prestige at 22oz. This was a very impressive model. It had the smallest span at 3.7m but chord was the typical 250mm for a J plane. So he did not suffer too bad in visibility but had a couple mph advantage in speed mode (assuming roughly equivalent L/D's). So far the real world racing setup seems to be settling out at around 30-35mph in cruise (clean wing) and 40-55mph (reflex/down elev trim) in speed modes. Even though Kolb's Prestige aspect ratio was the lowest I don't think this cost him anything significant at the very low angle of attack in the 40-50mph speed mode range of the flight envelope relative to the higher AR models (correct me if I'm wrong, I'm no aeronautical engr).

Bill Chase's custom design Appersonic is an impressive racer and I know from head to head experience at Cal Valley that he is faster than my team's Supercon thanks to the higher wing loading. I have no idea how much his higher aspect ratio and very thin airfoil(profile) added to this (wing loading is much easier for me to understand). But with a root chord of 8 inches Bill has been proving that there is a limit to narrow chord/high aspect/high wingloading in real world XC racing conditions. Visibility IS important. We now know we dont have to sky out at 4,000+ ft with a 14inch chord MXC anymore. But 3000 ft is still fairly common in actual racing so it is looking like the typical 10" J plane chord is probably close to the practical lower limit. Given the 5kg limit and need for high 20+ oz loading this limits wingspan to 4m or less. I dont thing anyone has tried a 3.5m J wing yet which could be interesting and would give a loading increase to around 23-24oz.

So where is the optimum aspect ratio/chord/wing loading? We know that high L/D at 40-50mph airspeed is a key factor in escaping sink and bridging the gaps between thermals. The modern "J" plane wings are slightly better at 25-30mph but solidly outperform the older, larger XC racers like the SBXC and MXC in 40-50mph speed modes thanks to the higher wing loadings, improved airfoils and superior L/D.

I vote for reduced span and a minimum of 20 oz loading and 10" chord. In other words, Kolb's Prestige at 22oz and 3.7m edges out the rest. But not by much.

my 2c,

Steve
Last edited by TrekBiker; Aug 22, 2017 at 06:16 PM.
Aug 23, 2017, 02:36 PM
Registered User
Great flight, John. Unbelievable! Who would have ever expected road construction out in the middle of nowhere! That 300 miler is certainly a possibility.

Along the lines of optimizing planforms, I've been playing around with aspect ratio and reynolds number( without reinventing the wheel), in an effort to theoretically determine a best case scenario for the conditions encountered flying XC. Since I only have one more life left on the Appersonic :<), it looks like I'll probably be building an updated version this winter.
Aug 24, 2017, 10:46 PM
Registered User
Quote:
Originally Posted by Bill Chase
Along the lines of optimizing planforms, I've been playing around with aspect ratio and reynolds number( without reinventing the wheel), in an effort to theoretically determine a best case scenario for the conditions encountered flying XC. Since I only have one more life left on the Appersonic :<), it looks like I'll probably be building an updated version this winter.
That's good to hear Bill. I think the typical conditions in the Pioche area (Eastern Nevada) works well with a highly loaded glider. Wind, powerful lift and sink, and exceptionally good visibility means you need a glider that will move out of bad air quickly. Minimum sink is far less important since the thermals are usually strong enough for even a very highly loaded glider to climb. With the good visibility getting high enough is easier than most other areas we have flown. You only need to climb high enough to get to the next thermal!

Looking back at my gps log my high point was 4450' AGL. Most of the time I topped out between 3000' and 4000'.

John


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