rcjetsaok

My Feedback: (7)

Well guys, I had a bad Monday.... Met the gang in Waco to do some flying and I had a failure. It's hard to believe such a small inexpensive item can result in what happened.. But it did. My only advise is to check you linkages closely before flight, and have an "on the fly" understanding of what can happen if something lets go. I got the airplane under control briefly and turning to the field when I deployed flaps and gear to set up to land... It was then when it all went south. A broken Aileron clevis should not have been a problem all by it self. I had the airplane under control with one aileron and rudder. It's when the flaps went to full it got me.... The Crow mix came on, and only the left aileron came up, inducing a roll that was unrecoverable. The Crow never crossed my mind in this whole process, until about 3:20am the next morning when I woke up and it was plain as day... In thinking about the whole scenario, I would have to say that any airplane with Crow mix with Full flaps are subject to this situation. I would go on to say that if ANY ONE of the four surfaces ( aileron or flaps ) let go in that configuration it is most likely going to have the same result. All those control surfaces are working together and against each other to create the landing experience. I have learned a very expensive lesson the hard way that I will never forget. I just wanted to share it with you guy's.

Here are the three quick steps to disaster....


Cheers,

Danno

afterburner

My Feedback: (18)

Wow,
Sorry for your loss Danno. That pin breaking would be one of the last things I would think would fail. The pin must have been out of the hole for it to break like that. I gotta keep an eye on those locking clips.

Marty

indubitably

My Feedback: (14)

I have neve seen a pin failure before. Dont know how to prevent it. Those are good Sullivan clevises. How was your engine?
Hope it survived. They seem to get away with a lot of plane carnage.
John

Dr Honda

My Feedback: (4)

That sucks. sorry for your loss.

PaulD

My Feedback: (39)

The clevis must have opened first. There is no model aircraft servo on the planet that would create enough load to break off that pin in double shear - unless there was a flaw.

Really sorry to see that and for the loss of your airframe. I use those Du-bros lots and will definately be double checking all of mine.

PaulD

rcjetsaok

My Feedback: (7)

The Engine and Radio equipment appears fine as well as all the other components but everything is on its way back to it's appropriate manufacturer to be inspected and blessed for round two !!!! The nose gear had some damage and it too is on it's way to Florida. I'm looking for another one, seeing how I have every thing to drop in it.... I think I'll just have to call Patty and tell her to wrap a new airplane around that nose gear I sent in when Dustin is done fixing it !!!



Cheers,

Danno

roger.alli

Hey Danno,, Not Good..

I guess the only up side is that you have a definite cause.

I have those clevises on all the critical surfaces of my Bandits.. And to be completely honest, not all of them have the locking clips installed.. I will go home and remedy that tonight..

Thanks for sharing.

Roger

sskianpour

My Feedback: (2)

Sorry for the loss buddy. I too have a Kingcat, and she handles almost any situation well. I have CROW on a separate switch and was thinking of moving it as a mix to "full flaps" mode.

Seeing this, I will never do so!
Engine ok = New Cat! This one will last you over 1000+ flights!

Shaz

aquaskiman

My Feedback: (46)

After Seeing a ducted fan crash many years ago due to one flap dropping and the other not, I never take my finger off the flap switch tell I see the airplane flying stable. It saved my Rookie a few months ago. I was only about 75 ft high dropped flaps and it headed for the ground I got the flaps off and missed the ground by about 4 ft. Sorry for your loss.
Shaz I do put crow on my flap switch, but have a mix switch as well so I can have it on or off.

madmodelman

Thanks for the heads up Danno, gutted for your loss, as you say such a small component.

Regards,

Gary.

Meesh

My Feedback: (135)

That's a shame but thanks for sharing the cause with us. I carry spare clips with me in my tool box but you better believe I'll be checking them every flight after seeing this.

Bob

Robrow

Do you know if the pin failed in situ or as a result of the clevice opening up?

Rob.

AnthonyW

Years ago, my first Aggressor II was built with Flaperons. I was on approach and flipped the flap switch and the plane rolled inverted, I immediatly flipped it back, rolled the plane upright and then flipped the switch back again and it setted in and I landed with my heart beating faster than a BVM91R. Turned out it was the servo with an intermittent issue. You could tap the wing where the servo was and sometimes it would work and other times it wouldnt. I subsequently replaced all of thos model servo's. Sorry for your loss!
Anthony

tothemax

What a shame to lose that beauty. Sorry

pmerritt

My Feedback: (118)

They probably stamp those parts out so fast you couldn't keep count on the assembly line.  Roger.alli is right though.  A crash without knowing what on Earth went wrong always leaves that minuscule feeling of doubt the next time one goes flying.  You have the cause and now the knowledge what to do next time and we thank you for sharing that with us.  I think we all side on the fact that there is really no way one would ever be able to predict a structural failure like that.  Is there a part that is NEVER going to have some defect?  NO.  Can we afford to spend $1.3M like they do on passenger aircraft to have parts that shouldn't fail.  NO. 
Good luck on your recovery and hopefully you will have King Cat II up and flying soon.   God and gravity did a number on that one.  Sorry for your loss. 

rgburrill

I don't see a retainer on teh clevises you show. I do hope you use one to prevent them from opening.

rcjetsaok

My Feedback: (7)

The Clevis had had retaining clip on the airplane.. The first picture shown is a stock photo from Horizon Hobby website.... If that is what you are referring to.


Thanks,

Dan

bcovish

My Feedback: (8)

Look at the second photo, it shows the broken clevis pin

WHMC

My Feedback: (15)

Danno, Sorry for your loss. The old days had nylon horns that provided some self lubrication. The carbon fiber horns do not react well. My thoughts are lube with wax or teflon spray, use a keeper, as it will make everything smooth and keeps all working like a sewing machine. WHMC STL

MetallicaJunkie

sorry for your loss, such a shame a little part like that can cause a total disaster


I always thought you jet guys used dual control horns with ball links

[email protected]

My Feedback: (2)

How old are the clevis ?
Just could be that the carbon fiber ware is more the we expect.

Very cood time to look at my Bobcat and Kincat very closely.


Sorry for the lose but thank you the for info.

Kelly Rohrbach

My Feedback: (1)

So sorry for your loss.
In just the last year I have found three brand new Sullivan clevises right out of the package to be bad. Not broken pins but the end of the pin that is riveted in was not firmly in place. It would have broken off had I just tried to hook it to a control arm.
Now I look each one over real close and don't assume its fine. Overall I think they are the better clevises on the market but if its made it can fail. Sucks dude

kochj

I have had the pin fall out/break when trying to place it on a controll horn....
You need an act of congress to get these things to open and on a control rod when new...

The control horn was too thick and didn't let the pin fully engage into the other side of the cleveses .

rcjetsaok

My Feedback: (7)

I did send the Manufacturer a letter of the event and they responded. I had mixed feelings about sharing this with everyone because I do not want anyone to get the idea that I am out to point blame at this or any manufacturer in a truly freak accident, but instead to help them understand that even the smallest pieces of equipment that we use are all very important in our success. We all know that anything mechanical can break... That being said, the following is my e-mail and their response ( in reverse order ) I was impressed first of all that they responded and second of all I think they are concerned if there is a problem with their product.... Here it is, Take what you want away from it.

Dan



Dan,

This is a first for me although I have only been with Sullivan for 9 years, which around here is considered a short tenure. My first thoughts are that I am very sorry to see such a nice looking plane go down. It is always a sad and frustrating thing. My next thoughts are, why would this happen in this case, what could cause this type of failure in a clevis. We ship out a few hundred thousand a year and they just don't fail. This is greatly attributable to the fact that the clevises are stronger than any servo out there but I know servo technology just keeps getting better and they are even ganged together in some cases, although I don't expect that is the case on your aileron. In any case, even with the best manufacturing protocols in place there is always the possibility for defects or problems. It will be hard to determine with full certainly what happened here but we will do our best to investigate anyway to be sure there is no endemic problem that has made it through QC. We will start with some additional pull tests on our current inventory and check with our sources for any material or process changes that would relate to them. In the mean time perhaps you can help me with some things I am curious about that you may have answers to:

Do you have any clevises left from the pack that was used (a long shot but worth asking)
Were they used on other places on the plane?
What servo(s) / voltage was driving it?
What type of retaining device is used (stock clips, silicone tube, other?)

Sincerely,
Kevin Peryea
Sr. Engineer


Sullivan Products
1 N Haven St
Baltimore, MD 21224
P: 410-732-3500
F: 410-327-7443
www.Sullivanproducts.com

On 3/13/2012 10:58 PM, Dan Massey wrote:
> Dear sirs,
>
> I would like to share with you an experience I have had with one of your many product I have used and sold for you in our Hobby Shop for many years. I live in the greater Austin Texas area and our shop is located here as well. I have been an avid RC Modeler or 25+ years and yesterday I had a problem I have never experienced before. I was in Waco Texas flying at the HOTMAC flying site with some fellow Jet modelers from Austin and Ft.Worth. I was flying my BVM KingCat when I experienced a control failure in the roll axis. After a futile attempt to regain control af the aircraft it crashed. Upon inspection of the aircraft and all Radio equipment checked out, it was determined that the right Aileron push rod clevis pin (part#S526) had failed and causing the loss of the airplane.The clevis was properly installed and inspected before the flight and it flew normal into the flight for 3:25 minutes. The failure occured in a normal climbing left turn at aprox. 140mph, at that time the roll control was compromised and an attempt to control and land was unsuccessful. The Turbine was commanded and did shut down prior to impact, however the aircraft was a complete loss. All componets involved are being sent back to origin for complete evaluation and inspection, ie, Engine and Radio equipment for unseen damage, I wanted to make you aware of this situation in hopes that it can be addressed from a manufacturer stand point. In this case it was a very expensive loss, but thank God there was no injuries or property damage.It's very hard to believe and sobering that such a small inexpensive Item can cause this type of loss and the potential of a very dangerous situation.
> Please call me if you would like to visit more about this, I would be more than happy to share all the small details if it will better help you understand the chain of events that lead me to send you this letter.
>
>
> Sincerely,
>
> Dan Massey
> 512.650.3110
> [email protected]
> thehobbyexpress.com.

invertmast

My Feedback: (23)

Condolences on your loss Danno... Question, does the aileron control horn have a ridge on the clevis pin hole? It appears that the clevis pin has a fairly circular shear fracture on it. If their is any sort of ridge in the control horn from the manufacturing process, it is very possible that the horn slowly ate into the pin causing its failure.