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Old Apr 16, 2013, 05:40 PM
WINS - Winch In Nose Sailplane
jaizon's Avatar
USA, NH
Joined Mar 2008
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Quote:
Originally Posted by R.M. Gellart View Post
Just a question, how many flights on this ship prior to this flight? Any hard landings?

Marc
He said it was the first (and only) flight.
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Old Apr 16, 2013, 08:51 PM
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Demsey's Avatar
United States, FL, Daytona Beach
Joined Jan 2011
335 Posts
Hey guys, I don't have a dog in this hunt but I was at the field when Herman's sail plane went in. I am a friend of his and said I would post what I observed and what all the 'arm chair NTSB' investigators saw and discussed after we picked up the pieces.

I have a lot of modeling experience with just about every thing that flies, including some composite pylon racers but will admit composite sail planes are not my forte................

The sound of the boom breaking in flight is what drew my attention back to the model after I had watched the launch and Herman 'trimming' the plane for a minute of two on it's maiden flight.

At first the plane was actually coming down flat and somewhat under control but I could easily see the boom was compromised. My attention was then drawn to a 'piece' fluttering down above the model. Then, at a lower altitude another 'piece' left the plane and it too was falling. At that point the boom was gyrating around the fracture and the plane nosed in completely out of control. The initial failure happened quite high, around 600-800' so the fuselage was on the ground as the the two 'pieces' were still falling. As they came down they were easily recognizable. They were the elevator halves.

The wing was quite damaged. The main box spar having been broken in half and skin punctures as the two halves met. If I remember correctly aileron control rods and/or servo damage as well. All that damage I would attribute to ground contact.

The first thing I asked Herman was if he were pulling out of a dive. That would seem to me, and perhaps to others here the likely scenario. I wish for Herman's corroboration I could attest that he was indeed in straight and level flight, but as I mentioned the 'rifle crack' of the boom going drew my attention to the plane.

I know this is all subjective on my part as he is my friend, but I've never doubted his word. He's not a liar. He is an accomplished modeller who has a reputation of freely admitting when he 'dumb thumbs'. As I fully believed his testimony that the plane was in straight and level flight, which seemed fully likely as it was indeed a 'maiden' flight I started thinking of other causes given what I 'saw'.

I believe, that just prior to the boom going, one elevator half separated and left the air frame. Torque brought on by asymmetric lift/load moments broke the boom. That may account for the fact 'some' sort of control was happening when I first focused on the model immediate post failure. Then shortly the other elevator half departed and the rest was just waiting for the terrain to come up.

I have no info on the build or 'system' of the tail plane, whether design error or 'builder error' was at play, but I believe as I stated above; the horizontal 'flying tail' separated as the first link in the chain.

Good luck Herman!
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Old Apr 16, 2013, 09:14 PM
IT'S NOSE HEAVY!!!!!!!
cityevader's Avatar
United States, CA, San Jose
Joined Mar 2012
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Now that's the first post that has made sense!

The close-up of the boom shows it to have suffered multiple forces, as it's split in three different directions. Clearly (to me) a result rather than a cause, of the overall failure.
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Old Apr 16, 2013, 09:40 PM
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Joined Mar 2013
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jaizon, i have no answer of why did the Orion sailplane broke in the mid air. i will try to get more pictures of that Orion sailplane and just to entertain you. i could careless about what you're talking about. but, disrespectful to ww2 veteran is not acceptable. they might be old but they know honesty. you dont have to response or read my post. however, we are in this free country. so, take a easy and enjoy life.
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Old Apr 16, 2013, 10:04 PM
Brett
bjaffee's Avatar
So Cal
Joined Apr 2002
5,311 Posts
Quote:
Originally Posted by Demsey View Post
I have no info on the build or 'system' of the tail plane, whether design error or 'builder error' was at play, but I believe as I stated above; the horizontal 'flying tail' separated as the first link in the chain.
Good luck Herman!
That's a pretty huge piece of information right there, especially if it did not come apart symetrically. So the real question should probably be "why did the stab(s) separate" and not "why did the boom break."
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Old Apr 16, 2013, 10:15 PM
Registered User
San Diego
Joined Aug 2004
2,314 Posts
Herman,

It would have been helpful to this discussion if you had mentioned that one half of the stabilizer fell off prior to the boom failure (if I'm understanding Demsey's description correctly). The two piece design has to be taped together at the center in front of the fin. The full flying stab pivots freely on the joiner rod. Without the halves taped together it is possible (even likely) that the stab will eventually work its way free and fall off under normal flight maneuvers.

With only one stab attached there will be a large torsion (and bending) load on the boom at any moderate to high speed. The boom is likely not designed for this condition which might explain the failure.

FWIW
Tom
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Old Apr 17, 2013, 08:22 AM
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Joined Mar 2013
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kiesling,

i am not sure exactly what happened, .... is it consecutively, the Elevator separated first and then the tail boom start breaking ? or the tail boom broke first and then the Elevator start separating ? may be simultaneously ?

as per gary @soaringusa, he did advice me and i did, to put glue in the leading edge (front) tip of the elevator(small area on the side ). i also asked him if i have to glue the main wings. and his answer is "no" .

i'm sorry to all of you who read and response and trying to understand my explanation/description. anyway, thank you very much.
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Old Apr 17, 2013, 12:35 PM
IT'S NOSE HEAVY!!!!!!!
cityevader's Avatar
United States, CA, San Jose
Joined Mar 2012
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I'm curious what's at the front canopy area?
Is is tape residue? Marring/scratches/cracks?
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Old Apr 17, 2013, 12:48 PM
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Joined Mar 2013
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its combination of a electrical tape and double side tape to tie down the wires inside the canopy. thanks
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Old Apr 26, 2013, 10:41 PM
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gary g.,

please read this post/comments and looks at the pictures for you to understanding. thanks
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