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Old Feb 23, 2015, 03:08 PM
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Joined Dec 2014
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Radian Maiden Flight

Acquired the RTF after a 30+ year absence. Did a couple of popular mods:
- Sullivan rods with more rear support. With links attached there was a weight reduction of 17 grains, 1 gram, on the rods. No gram scale,, only a reloading scale. Sorry.
- Dubro ball links on the tail
- Repositioned elevator horn and added ply support about 3" across.
- Stuck a CF tube down the vertical stab
- Installed hinges on the horizontal and vertical.
- Ran a CF strip all along the bottom
- Package taped 2/3rds of the wing, top and bottom, out to the bend.
- Balanced CG at about 69mm with no additional lead required. That's just where it ended up. Marked where the battery was set and that was it.

Went to the local school yard with no one around. Anxiety was....maximized. First throw without motor was 15 yards. Grass in nose. Figured I wimped out. Put the battery back where is was supposed to be as it shifted forward. Put my big girl panties on and did a more robust throw, no motor. 65 yards and I had the controls (left/right/up/down) correct. Yah never know. I'm not that bright. Windy, 10-14 mile gusty breeze. Rationalized that I could always try to fix what I broke. Decided to go for it, powered up the motor and launched at half power. 30 degrees up, 150 feet or so. Powered off and puckered through a 4 minute, no thermal flight. Not that I was expecting more because of the breeze and the trees moving. No damage other that retarded flying skills. Considered myself lucky. Relaunched, another 4 minutes, no damage. Relaunched to 175 feet or so, noticing two red tail hawks 100 yards beyond me, circling my way. Managed to keep it in the air until they came nearer and then sort of played below them. Noticed the Radian was getting smaller and decided that I was stupid to have the motor running, even slowly. But.... the motor wasn't on. 13-15 minute flight in a moderate breeze. Got it down in one piece with no damage. What a true kick in the posterior. It actually worked. Dang.... thanks for all the help, folks. Appreciate it. Now....if the wind would just calm down.... It actually worked....it may be a beer cooler but I don't care...
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Old Feb 23, 2015, 10:00 PM
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Tucson, Az
Joined Feb 2007
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They make somepretty good flying beer coolers nowadays.
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Old Feb 24, 2015, 10:05 AM
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Yes, apparently. However, nowhere in the limited instructions was there a mention of where to mount the beer can. I assume directly over the CG. And in the wind, of course, adjust fluid levels accordingly.
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Last edited by kurtataltos; Feb 24, 2015 at 10:17 AM.
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Old Feb 24, 2015, 02:16 PM
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Round two.: a bit of a breeze but less windy than yesterday. Found it liked to porpoise. Set the trim near neutral and taped three nickles to the fuse in front of the vert stab. Flew with minimal porpoise. Does tend to "go more vertical" if full power is applied. Likely needs some more trimming. Measured the CG location with nickels taped on. Removed nickels and slid the battery back, marking the battery and the fuse location once balance was achieved. Measured 80mm from the leading edge, a shift of 11mm towards the rear. Some guy walked up and started asking a gaggle of questions and I replied, not realizing that the glider was staying up during the conversation. Easy 15 minute flight. Nice. For a beer cooler.
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Old Feb 24, 2015, 02:51 PM
InJamNoOneCanHearYouScrea m
United States, NH, Nashua
Joined Jun 2009
36 Posts
Kurt,
My Radian porpoises like mad after the mod. Best thing to do is dial in expo around the center of say 15%. This will soften your inputs and the Radian will fly better. Now that you have modified it will take a dive if you need to come down quickly without the wings coming off [I put magnets in the wing roots to keep that mess together].
Wally
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Old Feb 24, 2015, 02:56 PM
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The magnet idea is good. Thank you. Have taped the horiz stab. The magnets would work well on the main wing. enjoy !!
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Old Feb 25, 2015, 11:05 AM
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United States, CO, Denver
Joined Jan 2015
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Sounds like your enjoying your new plane. I have considered getting a Radian. While I was researching the Radian I found this video. It has good information and mods to make the Radian fly better and last longer.
Parkzone RADIAN Modification Clinic.mp4 (31 min 53 sec)
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Old Feb 25, 2015, 11:43 AM
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SportPlane, you are correct, an excellent link.

I am somewhat amazed at the CG settings he recommends. The manual notes 65mm, I started at 69 and have migrate to about 80mm with positive results. His video notes 95mm. I haven't migrated THAT far yet but am experimenting slowly.

I am also somewhat amazed at the interest passerby's have in the plane. It's not a high priced, high speed wonder, rather, a casual "enjoy a nice flight at your leisure" entry plane. Fielding lots of positive questions.

Enjoy !
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Old Feb 25, 2015, 01:56 PM
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United States, CO, Denver
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He adjust decalage after setting the CG that far back.
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Old Feb 25, 2015, 01:59 PM
turn, turn, turn.
Athol, Massachusetts
Joined Oct 2005
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Quote:
Originally Posted by SportPlane View Post
He adjust decalage after setting the CG that far back.
yep, change the CG, change the elevator setting.
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Old Feb 28, 2015, 09:06 PM
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Well....good news, bad news. Puffy dark clouds mixed with blue skies, light breeze. Did some more trim adjustments and put two quarters in the nose over three flights Seemed to be flying better with the added nose weight. Did a fourth launch and was doing fine as a cluster of really big fluffy, very dark clouds quickly rolled in. The Radian was below them and going up. I have no idea what the altitude of the clouds were but it was...way up there. W-A-Y up there. And the Radian disappeared into them. Down elevator got it back in sight and it wanted to go right back up....and did so 3-4 times, disappeared, back, disappeared, back. I'm now about 40 minutes into this flight and I can barely see the Radian. If I wasn't sure which direction it was going I put in left rudder. If it turned right it was going in the opposite direction I thought it was. I took the elevator trim control and clicked down 6. "High" is nice but this was getting out of hand . I got it down several hundred feet from the peak altitude at the end of the field, probably 375 yards horizontal from me, coming at me, when the wind starts up...now throw in a little rain with it (oh, yippee...) and I hit full throttle to fight the wind. Then the wind really ramps up...maybe 30-35 mph or better at my back and the Radian is making zero headway. After a 5 minute fight it simple "up and went". Lost sight of it. Gone. Went to the car, drove around the area for a half hour, nothing. Got home and there was a telephone message from someone who found it (phone number written on fuse). The plane managed to dual with a 200 foot tall redwood tree and lost. Some kids found it "rekitted", almost 2 miles away. I gave them a reward for calling. Wings and horizontal stab are ok as is the motor, 610 receiver, servo's, ESC, etc. But the spinner and the fuse are shredded. Pureed. I can repair a lot of things but this is "parts is parts" time. So.... it's time to get a new fuse, spinner, might as well get a new prop, then forge onward. If there any solace in the event I can say that a Radian will, on occasion, "go up", higher than it needs to. And I get to take what I learned on the first build and use it on the next. It was a kick in the pants, though. Luckily all the electronics still work. Quite the afternoon... can't screw around with mother nature.... Life happens!
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Old Mar 02, 2015, 09:11 AM
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United States, CO, Denver
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Wow! sounds like you had a great time flying your Radian. It was nice to have your glider returned.
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Old Mar 02, 2015, 01:35 PM
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Yes, it was a great time flying, all things considered. Given that the weather over the past couple of weeks hasn't been real conducive to thermals, things were still doing very well. Until....of course....things weren't doing well.

Having a couple kids find the plane and call was a "good thing", very lucky. I think they were enamored with "what is it", asking questions, etc. So, it was a lucky result. What was odd was that, after losing site of the plane, I turned the transmitter off. I think....the control surfaces all returned to "neutral". That's the only way I can account for the distance traveled after I lost sight of it (as it was substantial).

And I will not soon forget the Radian simply disappearing into a cloud, multiple times. A really unique experience that does not need to be duplicated. I will try to be a bit more sedate in the future. New fuse arriving in a couple days so then it's back to construction. Overall, turned out very well.
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Old Mar 05, 2015, 10:12 AM
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I used to fly Hang Gliders and while flying had a few experiences with getting sucked up into a cloud. Fortunately my glider was of the high performance variety and I was able to escape the cloud suck and fly about a 1/4 mile out to the edge of the cloud. It is pretty amazing how I quickly went from just climbing out in a strong thermal to trying to escape getting sucked into the cloud. I did have to fly through the cloud to get out of it as the air was rising too fast for me to try to dive down out of it. You can't see it from the ground but when you are up under the cloud the center of the cloud is much higher than the edges. It is a strange experience to look straight out at the horizon and have to look down 500' to see the edge of the cloud and sunlight. Getting sucked into a cloud is a very dangerous situation for a glider carrying a human and should Definitly be avoided.
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Last edited by SportPlane; Mar 05, 2015 at 01:55 PM.
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Old Mar 11, 2015, 04:03 PM
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Joined Dec 2014
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I finally got my Radian into what I perceived was "re-flyable" condition. The severed front just in front of the LE was reattached with CF rods to the front/back, CF strips added to the sides to compliment the top and bottom CF strips, and a lot of gorilla glue and other patchwork. I figure it has to be porkier than it was originally but if it flew like a pig, so be it. Re-balanced. Went out today, partially cloudy, semi-overcast, a bit of a breeze. First flight, 5 minutes, no harm, no foul. Second flight... motored up to about 350+ feet and then all heck broke loose. I transitioned from point "a" to point "b", wing lifts, turn into the lift, up it goes. Lose the lift after a couple minutes, repeat a transition, tip rises, turn into it, up again. Clouds moving in and I'm going up. Stayed at about 800 feet for about 5-8 minutes and then the updrafts to the cloud cover inquired "are you going up???". Yes, I replied. I managed a full rookie move and lost it in the overcast/clouds, maybe 1200 feet. Put in 4 clicks of down and 4 of left. It came out about a minute later. Nearly peed in my pants. For some reason it just seems like the clouds should be higher. True,, the Radian was... small... very small, but still. At that point I figured out that being that close to the cloudy overcast meant "lift everywhere" and it was true. I just added two clicks of down trim and cruzed anywhere I wanted and it just stayed at about 1000 feet. No need to look for lift. An hour later I said "ok, enough is enough, don't press your luck" and brought it in in one piece !! Yay! It actually landed in the same condition it took off in. Who wudda thunk? It may be porkier but I guess pigs do fly. Oink Oink
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