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Old Apr 04, 2012, 09:44 PM
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**Update** Fixed my busted plane - now it's forgotten how to fly! - Fixed!

So if you remember me from my last thread, I had the joy of crashing my plane nose-first into the ground, from about 300' up, at full speed! The damage surprisingly wasn't too bad, and I managed to put it all back together.

However, today I took it out to fly, and it quickly crashed and burned. Unfortunately this time it tipped and snapped the wing in half! Fear not, a quick bit of toothpicks and tape, and it's as good as new again. Except it's still forgotten how to fly....

Basically, what it's doing is that when I launch it, it seems to have almost zero power. I give it a bit of up elevator to keep it form smashing into the ground, and it seems to quickly stall, tip to the left, and crash down. It seems like it's lost almost all of it's dyhedral (?) over the wings, and can't keep itself upright. Would installing the motor back on the plane out of alignment cause it to do what it was doing?

If it would help, I could post a video of what it did when it crashed and snapped the wing (I couldn't even get it to stay up in the air for 5 seconds). But maybe my description above was enough for you to point this poor n00b in the right direction to get his plane flying again!

Thanks!
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Last edited by kenzietech; Apr 05, 2012 at 07:24 PM.
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Old Apr 04, 2012, 10:27 PM
Shelter Kitty "Orange Death"
bartricky's Avatar
United States, FL, Monroe
Joined Jan 2008
3,165 Posts
If the prop is on backwards you will have very low power.
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Old Apr 04, 2012, 10:35 PM
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Originally Posted by bartricky View Post
If the prop is on backwards you will have very low power.
Good thinking. Thankfully, the prop itself didn't separate from the bolt / collar thing that holds it onto the motor. So it should be in the same orientation that it was before.

Interesting thing though, before I read your post, I was out there testing that very thing! Well, I knew the prop had the correct orientation, but I thought that maybe it had gotten nicked in the crash, and the WH came with a spare prop. So I put it on, to see if it made a difference. Problem though was that it's night time outside, so I couldn't fly it. So I was wondering how to tell if it was going to give me more thrust or not. And then I had a brilliant idea!

I went inside and grabbed our food scale, and brought it into the garage! I turned it on, tared the value of it to 0 with the plane on it, nose down, and then turned on the motor full speed. Success! Tared at 0, the prop was giving me about 210g of thrust. I then swapped it with the old one, and it, too, gave me about 210g of thrust. So unfortunately the prop wasn't the culprit of the issue. However, while I was playing with the scale, I did turn the prop around for kicks and see what I got for thrust. The result? About 90g of thrust. No wonder a friend of mine, whose prop was on backwards, couldn't get his plane in the air!

Though that does raise another question. If the prop's only pushing about 210g of thrust, but my plane weighs about 660g, is that sufficient enough power to push it through the air? Obviously it should be, since the plane came like that, and it flew before. But does that mean that if it would be able to provide greater than 660g of thrust, that it would effectively give the plane infinite vertical climb?

Math is fun!
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Old Apr 05, 2012, 06:33 AM
Winter Haven FL
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Joined Dec 2003
508 Posts
Just going by what you have in the description, it really would be difficult to tell what the issue(s) is(are), but judging by what you said about the crash, the first thing I would check is to see if it was a balancing problem either CG due to shifting during the crash and balanced nose to tail along the longitudinal axis. This can increase the tendency to torque roll.

Not to beat a dead horse, but this is an example of one of the problems with today's out of the box solutions to get someone in the air as cheaply and quickly as possible, when stuff like this happens, newer guys dont know how to fix things easily. Good luck and let us know how it turns out. If this doesnt work, describe the flight characteristics better and maybe post a pic or two.
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Old Apr 05, 2012, 09:55 AM
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Originally Posted by Byrdman View Post
Just going by what you have in the description, it really would be difficult to tell what the issue(s) is(are), but judging by what you said about the crash, the first thing I would check is to see if it was a balancing problem either CG due to shifting during the crash and balanced nose to tail along the longitudinal axis. This can increase the tendency to torque roll.

Not to beat a dead horse, but this is an example of one of the problems with today's out of the box solutions to get someone in the air as cheaply and quickly as possible, when stuff like this happens, newer guys dont know how to fix things easily. Good luck and let us know how it turns out. If this doesnt work, describe the flight characteristics better and maybe post a pic or two.
Byrdman, I threw the short video up on YouTube:

Failed flight after previous nose-dive repair! (0 min 51 sec)


Please ignore the pansy throw for the first launch. I chickened out, thinking the plane was going to fall apart after fixing it, so I wussed out on the launch, lol. The second one should have been better. But you can see what it did in the video. I think the flight was too short to really gleam any information out of it. I've taped up the wing, and will try to take it out again tonight with a known freshly charged battery, and see how it goes. Though maybe having you guys take a look at the video, your expertise may show you something obvious that I missed on the video.

I did check the COG last night on the plane as well, and it seemed to be decent. It was pretty much right about the center of the wing spar, about 2 1/2" - 2 3/4" from the leading edge of the wing. It should be pretty much where it was before the crash, and it flew wonderfully then. I had to put some glue / tape on the plane to fix it, but for the most part it was pretty much 50/50 as far as how much was put forward of the COG, and put behind the COG.

Maybe throwing a washer or two into the nose of the plane to push the COG a bit farther forward, just in case?

Thanks!
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Old Apr 05, 2012, 10:11 AM
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Joined Mar 2010
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Throw the plane LEVEL and a tad harder. You're throwing it at way too steep an angle and it's stalling...
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Old Apr 05, 2012, 04:18 PM
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I think the wind is supposed to be a tad stronger than what I normally like, but I'm going to plan on taking it out anyway now that the wing's been taped, and see if it was just an issue with my launches yesterday.

*Fingers crossed!*
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Old Apr 05, 2012, 07:29 PM
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She lives!

I had a chance to take it out again tonight for a test flight. Unfortunately, the place where I usually go to was taken over by soccer kids, so I had to find another place. I ended up in a new home construction area, and decided to press my luck there. And it paid off!

We had a lot more wind today, and I was flying in 10-15mph winds. Way too strong for the Wild Hawk. But I pointed the nose into the wind, and chucked it a bit harder this time. And it took off, right into the air, climbing quickly! I quickly trimmed down the elevator, and tried to level it out. I got it under control, but man it was hard to push it against such strong winds! For awhile there, it wasn't making any progress, but simply pretty much just hovering in the air. Turning it into the wind was a chore too, because the trailing wing just dropped like a rock! But I was able to recover, and I gave it a few circles, and landed it gently.

One more quick launch, a few loops, and another gentle landing, and I was satisfied with the condition of the plane. It seems to fly just fine today. I'm guessing I just chickened out with it yesterday, caused it to tip stall, and the rest was history. But today it flew quite nicely, and I'm stoked for another calm day to take it back out and get a good 45 minutes of flying in!

Thanks all for your help and advice!
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