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Old Jul 13, 2005, 05:36 PM
Up and Dowwwwnn
Tampa, FL
Joined Jul 2004
411 Posts
It finally caught up....stupid crash

It finally happen, I crashed my UCanDo. I just traded my trainer for it to learn some aerobatic. It was a sad day yesterday. Don't know what really happened. I took a small dive and after a second, what looked like a large section of covering ripped out of the right wing. But when I got to the crash site, found out that it was the damn right aileron. It was ripped clean from the hinges. A more experienced pilot could have saved the plane but it was beyond my control. I didn't know that the aileron came out and the plank was going down in a spiral, so I kept giving it right aileron to bring up the left wing but in-fact I was making it roll even faster. Finally it went out of my control and crashed upside-down, head first. All the electronics survived and the TT .61 was fine also. Only the fuel tank was cracked and started leaking. It was its second flight. I checked everything before the flight to look for any weakness or anything awkward. Don't think I will trust another ARF though. When I will have enough saved for my next UCanDo (I just love the design and the looks) I will beef up the hinges and controls surfaces. The only thing that survived was the tail section, lol. It was untouched. I will save it for my next one jsut in case.

It sucks...but now or later I knew I was gonna be a victim....
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Old Jul 13, 2005, 05:46 PM
I don't want to "Switch Now"
pmackenzie's Avatar
Toronto (Don Mills), Canada
Joined Dec 2002
17,100 Posts
It sounds like the dive resulted in too much airspeed. This caused the aileron to flutter and come off. You might have also had too much pitch on the prop.
Before you re-use any of the servos check the gears carefully. If the one that lost the aileron is stripped, then it was probably flutter.
Pat Mackenzie
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Old Jul 13, 2005, 05:54 PM
Up and Dowwwwnn
Tampa, FL
Joined Jul 2004
411 Posts
Quote:
Originally Posted by pmackenzie
It sounds like the dive resulted in too much airspeed. This caused the aileron to flutter and come off. You might have also had too much pitch on the prop.
Before you re-use any of the servos check the gears carefully. If the one that lost the aileron is stripped, then it was probably flutter.
Pat Mackenzie
Yaa, thats what most of the ppl told me, but the dive was not long enough to pick up so much speed. Maybe I expected to much from the frame. Dont know what the Pitch was but my friend Paul (whos a genius and a superb flyer) did tell me to lower to pitch. But he said that might not be that bad. I jsut wanted to go up and check it out before I made the prop changes. Good idea on the servo check-up. I will go home tonite and test all of out. Thanx a lot Pat.

Virat
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Old Jul 14, 2005, 01:38 PM
SSP#14 aspirant
Soar_dude's Avatar
Fort Lewis, Washington, United States
Joined Feb 2002
1,289 Posts
It looks like not enough CA on the hinges. They look pretty clean to me.

Soar Dude
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Old Jul 14, 2005, 02:01 PM
RCAPA #005
MGBGTRacer's Avatar
USA, VT, Springfield
Joined Jan 2004
3,858 Posts
pin them thar hinges next time. You did CA them, right? Many many years ago I bought an ARF trainer and I assumed the hinges were pre-CA'd since I tugged on the elevator and ailerons and they were on tight... bad assumption. The slots were a tight fit, but the hinges weren't glued. Didn't crash, but made for an interesting landing.
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Old Jul 14, 2005, 02:55 PM
Up and Dowwwwnn
Tampa, FL
Joined Jul 2004
411 Posts
The UCanDo was slightly used. I got it from a local flyer when I traded my trainer in. I saw him fly it before so I am sure the hinges where fine. I also checked the surfaces before I flew it since it was in a garage for some time, but they all looked in good shape. My thought is that, like Pat Mackenzie said, the dive was really fast and the aileron couldnt handle it. I am kinda inexperieced so I cant really figure how fast the plane was going. I dont know wat else but it jsut sucks now I have to wait till i get another one.

Pat - You were right the aileron servo is stripped. It was all gone. I think it was stripped when the surfaced started to flutter.

Thankx guys.

Virat
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Old Jul 14, 2005, 03:21 PM
Registered User
Clear Lake City Metroport, Texas, United States
Joined Aug 2004
301 Posts
I used to have a UCD-3D and the same thing happened to me. Replace the CA hinges with Robart hinges, and use about 10 of them on each side. Gang them up near the aileron root, as this is where the prop wash vibration tore mine loose.
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Old Jul 14, 2005, 09:08 PM
Up and Dowwwwnn
Tampa, FL
Joined Jul 2004
411 Posts
Quote:
Originally Posted by pimmer
I used to have a UCD-3D and the same thing happened to me. Replace the CA hinges with Robart hinges, and use about 10 of them on each side. Gang them up near the aileron root, as this is where the prop wash vibration tore mine loose.

GOod stuff... I will keep that in mind....I will be gettin another one cause i really like the way it looks....sorry aobut ur loss i am sure I know how it feels lol.
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Old Jul 15, 2005, 11:57 AM
ProBro #1889
DsWright's Avatar
United States, OH, Amelia
Joined Aug 2004
603 Posts
10 on each side? LOL

CA hinges are fine. The best thing to stop flutter is remove all play from the clevises and the servo horn area.. you should not be able to move the control surface without the servo turning when you move it.

Most ARF's have lower quality hardware, it wears after a while and devolops slop.

No need to add 10 hinges to each side... that STILL won't stop it from fluttering.... CA hinges are fine. Just install them properly.

99% of the people that complain about CA hinges don't install them properly. They will last as long as any airframe.
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Old Jul 20, 2005, 10:10 AM
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Herleman's Avatar
Daytona Beach, Florida, United States
Joined Nov 2003
1,524 Posts
You might also see to it that the gap between the aileron and the wing is sealed with packing tape or some additional iron on film. Getting too much air through that gap will cause flutter quickly on the Ucan (I have an unblemished tail section, Just like yours, and a bent shaft from the Saito .72). Be sure that everything is well set. Pin the hinges just for safety sake in addition to the gap sealing. When you are all done, tug on the ailerons really hard. If anything moves, start over.
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Old Jul 20, 2005, 02:18 PM
Up and Dowwwwnn
Tampa, FL
Joined Jul 2004
411 Posts
Quote:
Originally Posted by Herleman
You might also see to it that the gap between the aileron and the wing is sealed with packing tape or some additional iron on film. Getting too much air through that gap will cause flutter quickly on the Ucan (I have an unblemished tail section, Just like yours, and a bent shaft from the Saito .72). Be sure that everything is well set. Pin the hinges just for safety sake in addition to the gap sealing. When you are all done, tug on the ailerons really hard. If anything moves, start over.
I never knew that sealing the gap was that important. Then again I'm not that experienced and its good to know. I will be sure to fix the gap and this time the hinges are going nowhere cause I will be pinniing them down good. BTW The tail section, which was in great shape, was jsut stepped on by my sister and now is in trash. Guess the whole plank was never meant to exist. Thanx a lot.

Virat
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Old Jul 21, 2005, 10:49 AM
ProBro #1889
DsWright's Avatar
United States, OH, Amelia
Joined Aug 2004
603 Posts
the type of hinges doesn't really matter as long as they are properly installed, CA hinges are FINE. Sealing the gaps does however help.

The problem is Flutter. Do a search here and on RCU on the word flutter and read up. This will keep your next UCD from taking a dirtnap.

spending extra $$ and time on pinned hinges is your choice, however that extra $$ and time won't save your airplane if it flutters... Instead of the aileron coming off, it will just transfer it to the next weakest point, possibly servo mount and break it, and you still end up in the same situation.....

Ask the Funtana .90 guys, alot of them have learned about flutter the hard way. usually after they are done picking up the toothpics that used to be an airplane=P
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