Author Topic: Abrupt end at 4’ (Read 22832 times)

Joseph Daly · « **on:** August 20, 2023, 03:38:59 PM »

Sadly lost a good ship! It came to a very abrupt end when the up line failed. I was just coming out of the triangles at about 4’ and then the hardest outside corner I have ever seen!!!!

I think I am most upset about the prop and spinner!

Dave_Trible · « **Reply #1 on:** August 20, 2023, 03:59:05 PM »

Oh sorry Joe! Looks like maybe it let go at the bellcrank? The picture goes a little fuzzy when you expand it.

Dave

Joseph Daly · « **Reply #2 on:** August 20, 2023, 04:03:57 PM »

Yes right at the bellcrank

Joe Gilbert · « **Reply #3 on:** August 20, 2023, 04:06:59 PM »

Joe , that sucks my friend.

Paul Taylor · « **Reply #4 on:** August 20, 2023, 04:18:01 PM »

Oh Snap!!!
Sorry that happened. 😳

Mike Palko · « **Reply #5 on:** August 20, 2023, 05:56:43 PM »

Sorry to see this happen Joe.

Paul Walker · « **Reply #6 on:** August 20, 2023, 05:59:21 PM »

Sorry about that Joe.
I feel for you. I lost a very good plane earlier this year. Still hurts.

Brett Buck · « **Reply #7 on:** August 20, 2023, 06:09:12 PM »

Quote from: Joseph Daly on August 20, 2023, 03:38:59 PM

Sadly lost a good ship! It came to a very abrupt end when the up line failed. I was just coming out of the triangles at about 4’ and then the hardest outside corner I have ever seen!!!!

I think I am most upset about the prop and spinner!

Sorry to see this, Joe. I hve built something like 60-ish airplanes over the decades, and I have 3 of them left, so I know how it goes.

Brett

Trostle · « **Reply #8 on:** August 20, 2023, 06:38:23 PM »

Quote from: Joseph Daly on August 20, 2023, 03:38:59 PM

Sadly lost a good ship! It came to a very abrupt end when the up line failed. I was just coming out of the triangles at about 4’ and then the hardest outside corner I have ever seen!!!!

I know my story does not alleviate your loss of a good airplane. I had a similar situation about two years ago with my 5th Chizler. I apologize in advance for barging in on your thread.

I had finished the pattern, waiting for the fuel to run out. It was level, no more than 5 or 6 feet, full power. The up line (solid music wire lines) broke at the eyelet connecting it to the leadout at the wing tip. I experienced the same thing you did that something happened and before there was any reaction, the thing went straight into the ground. (At 50 mph+, it does not take much time to impact the ground from 5 feet.) Our circle (actually a ring) is covered with a Geotech covering over a fairly soft sandy/soil surface. The airplane was vertical when it hit the ground, a neat round hole where the spinner penetrated the covering. The impact did not even break the 3-blade carbon prop because it was so vertical. One blade had a small crack. Sort of proves that these things can turn a 5 or 6 foot corner. There was not much left of the Chizler. The engine is still being run in another new Chizler.

Keith

Motorman · « **Reply #9 on:** August 20, 2023, 06:40:25 PM »

Oh sorry, was that lead out crimped or wrapped?

Dennis Nunes · « **Reply #10 on:** August 20, 2023, 07:38:22 PM »

Quote from: Joseph Daly on August 20, 2023, 03:38:59 PM

Sadly lost a good ship!

Why is it that it that it's always the "good" plane that gets destroyed and not the plane that we continue to fight with that deserves to be in the trash can?

Dennis

Matt Colan · « **Reply #11 on:** August 20, 2023, 07:52:56 PM »

That really sucks to see Joe! I know the feeling

kevin king · « **Reply #12 on:** August 20, 2023, 07:57:07 PM »

My sincere condolences Can i ask what size of music wire you were using?

Kevin

William DeMauro · « **Reply #13 on:** August 20, 2023, 08:20:11 PM »

The plane went in almost perfectly vertical. I will post a close up of the lead out failure that I took. It is easier to see and I will post a picture of the motor as it ended up on the ground. Two cells of the 6 cell pack were destroyed. The prop does not even look broke but it is. I suspect the motor can be rebuilt with new bearings and it will fly again.

Shorts,David · « **Reply #14 on:** August 20, 2023, 08:32:03 PM »

Uh oh, sorry to see that Joe. That looks like the same belcrank I just put in my new plane.

Ken Culbertson · « **Reply #15 on:** August 20, 2023, 08:41:35 PM »

Quote from: Shorts,David on August 20, 2023, 08:32:03 PM

Uh oh, sorry to see that Joe. That looks like the same bellcrank I just put in my new plane.

Same here. Was it one of the Okie/Morris sets that was already wrapped at the BC? Maybe it is just the Pix but it looks like it was soldered. Curious, how many flights on the plane.

Ken

James Mills · « **Reply #16 on:** August 20, 2023, 09:35:02 PM »

Sorry to see that Joe, definately sucks.

James

Brent Williams · « **Reply #17 on:** August 20, 2023, 11:08:47 PM »

Sorry to hear about the loss of a great plane to equipment failure.
What is the termination method on the leadouts? Looks kind of like an aluminum crimp sleeve under the heatshrink?

Tom Luciano · « **Reply #18 on:** August 21, 2023, 08:38:34 AM »

Looks repairable,no?

Paul Wescott · « **Reply #19 on:** August 21, 2023, 08:48:53 AM »

Quote from: Tom Luciano on August 21, 2023, 08:38:34 AM

Looks repairable,no?

Too soon.

AMV · « **Reply #20 on:** August 21, 2023, 11:50:53 AM »

Sorry to hear about this, Joe. I feel your pain -- I wrecked your old High Voltage last October turning too late out of outside squares...all that remains is the wing (really nice and solid!) and chunks of stab. Now I have even more trust issues with the ground! I gotta rebuild the whole fuse. At least your whole airframe is mostly intact!

Cheers,

- Andrey

Bob Hunt · « **Reply #21 on:** August 21, 2023, 12:01:42 PM »

Hi Joe:

Let me add my condolences to the rest here. We all know exactly how that feels. I lost my "Bronze Dog" Saturn just a few days before leaving for Sweden to compete in the 1996 World Championships. the cause was a broken pushrod just behind the flap horn. That ship had hundreds of flights on it. I cost me that trip; Billy had to go in my place. The worst part of the story is that I lost the brand new Saturn just a week earlier at the Nats due to a broken leadout. Two in one week from broken wire. Ouch!

Again, sorry for the loss; you'll bounce back (perhaps "bounce" was a not too sensitive a remark?).

Later - Bob

frank williams · « **Reply #22 on:** August 21, 2023, 05:59:55 PM »

Oh My ...... very sorry for the loss of a beautiful airplane .... been there , done that , ..... except mine was with a PA75 two weeks before the Nats

Doug Moon · « **Reply #23 on:** August 21, 2023, 06:03:21 PM »

Wow that sucks!

I use that same termination on some of mine. But that looks soldered? I dont solder. It creates a weak spot.

I too know your pain. I was flying probably one of the best planes I have ever built. 4s powered model. Pattern was done sitting about 8-10' waiting for the fuel to run out. There were two doves sitting right on the edge of the circle. They were there the whole flight. I basically flew all of my maneuvers right above them. They never flinched. I forgot they were there as the flight was ending. I glanced left for a split second just to eye the path forward setting up for landing. As I knew the run out was coming very soon. At that moment as I flew above the two birds they flew off. One of them went right into my lines. It violently jerked the handle from my hand and thong pulled tight and did it's job. Full down instantly and the model was lost. The Saito 56 head was broken clean off the case. The Eather prop was demolished. The bird was killed. I am still mad at that bird all these years later.

Doug Moon · « **Reply #24 on:** August 21, 2023, 06:04:00 PM »

oops double post...

Doug Moon · « **Reply #25 on:** August 21, 2023, 06:07:38 PM »

Joseph Daly · « **Reply #26 on:** August 21, 2023, 07:25:55 PM »

Thanks for all the condolences.
The wire was .027” wire, crimped. The plane only had 184 flights on it and it will likely live again.

Anyway, so it is next plane up!!! Plenty more on the bench and good news it helped with the decision on what plane to fly at the TT! LOL

john e. holliday · « **Reply #27 on:** August 21, 2023, 10:30:55 PM »

Hope you realize that you should never use a crimp on a long term installation. I use swagging on cable and copper wrap on solid wire.

Air Ministry . · « **Reply #28 on:** August 22, 2023, 06:48:38 AM »

It wouldve been more abrupt from 40 foot .

doug coursey · « **Reply #29 on:** August 22, 2023, 07:58:58 AM »

Quote from: Joseph Daly on August 20, 2023, 03:38:59 PM

Sadly lost a good ship! It came to a very abrupt end when the up line failed. I was just coming out of the triangles at about 4’ and then the hardest outside corner I have ever seen!!!!

I think I am most upset about the prop and spinner!

was that an okie or tom morris bellcrank? I have some of both

AMV · « **Reply #30 on:** August 22, 2023, 10:23:31 AM »

Quote from: Joseph Daly on August 21, 2023, 07:25:55 PM

Thanks for all the condolences.
The wire was .027” wire, crimped. The plane only had 184 flights on it and it will likely live again.

Anyway, so it is next plane up!!! Plenty more on the bench and good news it helped with the decision on what plane to fly at the TT! LOL

NEXT VICTIM!!!

Ken Culbertson · « **Reply #31 on:** August 22, 2023, 05:53:51 PM »

I have never questioned the bellcrank connection on the Morris, or Okie for that matter. Both were covered with heat shrink and I just assumed them to be better than I could do by myself. Crimps are the work of the Devil and have no place in our toys. A folded wrapped connection will never fail.

Ken

John McFayden · « **Reply #32 on:** August 22, 2023, 06:26:35 PM »

A folded wrapped connection will never fail.

The Titanic will never sink

Bob Hunt · « **Reply #33 on:** August 22, 2023, 06:47:23 PM »

Quote from: John McFayden on August 22, 2023, 06:26:35 PM

A folded wrapped connection will never fail.

The Titanic will never sink

The Titanic was crimped...

Bob

Dan McEntee · « **Reply #34 on:** August 22, 2023, 07:16:46 PM »

Quote from: John McFayden on August 22, 2023, 06:26:35 PM

A folded wrapped connection will never fail.

The Titanic will never sink

I can say this now at my age, I think without fear of jinxing things, and that is I have never had a lead out fail since I started this whole deal and after I learned about wire wrapping early on. I have lost three airplanes in my time, each was when using a factory crimped set of Sullivan lines, and each time a line broke at the handle, up inside the crimp sleeve. After the last one, Sullivan lines are only used after I clip the eyelets off and replace with wire wrapped!!

Type at you later,
Dan McEntee

Ken Culbertson · « **Reply #35 on:** August 22, 2023, 09:20:30 PM »

Quote from: Dan McEntee on August 22, 2023, 07:16:46 PM

I can say this now at my age, I think without fear of jinxing things, and that is I have never had a lead out fail since I started this whole deal and after I learned about wire wrapping early on. I have lost three airplanes in my time, each was when using a factory crimped set of Sullivan lines, and each time a line broke at the handle, up inside the crimp sleeve. After the last one, Sullivan lines are only used after I clip the eyelets off and replace with wire wrapped!!

Type at you later,
Dan McEntee

Amen

Fred Underwood · « **Reply #36 on:** August 23, 2023, 02:28:40 PM »

Joe, Sorry to see the loss of a nice plane and all of the work.

I have a similar looking bellcrank and have taken it apart. The leads are wrapped around a brass piece and that inserted into the slot for rotation. The brass pieces has a large hole and that is sized down with what seems like soft aluminum. The aluminum sleeve is several thousandths taller than the brass, so the aluminum may be held in the slot by pinch, and then the brass rotate on it. The one that I received was overly tightened and didn’t rotate, so disassembled. The bolt is not a sleeve bolt, so threads are against the aluminum, but maybe the aluminum is clamped and doesn’t rotate on the threads. Mine was tightened and then didn’t rotate in the brass even when loosened. It did rotate on threads.

The bellcrank is shown with the leadouts/shrink hitting the slot. This happens at about 45 – 50° in either bellcrank position as shown. If you use more bellcrank throw (greater that 45°) for mechanical advantage or because of arm lengths, then you impinge and force the rotation point to the leadout crimp, but similar if wrapped or crimped. There is a forced articulation or rotation in the joiner area if the leadout hits the bellcrank, or if the pivot gets jammed with/by the aluminum.

This is not my field, so my observations and comments may not be correct.

Joseph Daly · « **Reply #37 on:** August 23, 2023, 04:17:00 PM »

Just to be clear the crimp didn’t fail. The wire broke and it appears to have happen like Fred describes. There is was a sharp corner on the edge of the Leadout cut out in the bellcrank and it was touching only on up hard control and sometimes I fly pretty hard. Obviously from now on I would relieve and radius that area.

Thank for all of the condolences.

Joseph Daly · « **Reply #38 on:** August 23, 2023, 04:25:43 PM »

Well, when it rains it pours for me!!!! Today I took out my NATS plane to practice for the Mass Cup. On the 6th flight of the session during the 2nd outside square the wing folded and all I could do is watch the plane try to fly and I thought maybe I could save the prop by putting in the grass. Well it had other idea and started climbing to the top of the circle and all I could do is watch as it pounded into the pavement!

This one hurts as it was one of my best planes and it is the one that got me into the top 5 in 21 and it won at Triple tree this year.

I am not sure why the wing folded yet. It was pretty windy today and this plane has been flown it some real bad wind in the past. When I get some time I will look at to determine the failure. This one is a shame!

Ken Culbertson · « **Reply #39 on:** August 23, 2023, 04:29:01 PM »

I wonder how many others are experiencing the same issues. I put stops on my bellcranks for other reasons, but I have noticed that the slotted ones did not allow full movement without "bending" in the connection slot. This repeat bending could weaken the wire, or tighten a connection to the breaking point. I cut mine out and smooth them with a rat tail file to make sure they didn't bend the connection. This sure has been a year for things that we took for granted failing.

Ken

Sorry, I didn't see your last post when I posted this. Two front line ships in such a short time. I feel your pain.

Matt Colan · « **Reply #40 on:** August 23, 2023, 06:16:47 PM »

Wow Joe! That really really Sucks!! Sorry to see that!

Dave_Trible · « **Reply #41 on:** August 23, 2023, 07:02:53 PM »

Joe so sorry. Sometimes that dark cloud seems to follow you around. At least you have a good excuse to build more planes this winter. I just started two new ones just when I thought I was well equipped for a couple years. Was this one a take-apart? That's where I've had a couple fail me in the past. You simply give up some structural integrity for the take apart ability. Either that or hidden spar damage from a few rough landing shocks then one day......

Dave

Paul Walker · « **Reply #42 on:** August 23, 2023, 09:20:22 PM »

You simply give up some structural integrity for the take apart ability.

Dave
[/quote]

Maybe you do. But done right, they are just fine. I have many that will attest to that.

Air Ministry . · « **Reply #43 on:** August 23, 2023, 09:39:59 PM »

" Sorry, I didn't see your last post when I posted this. Two front line ships in such a short time. I feel your pain. "

They say things happen in threes ! Quick . Get out your worst aeroplane and leave it behind your car . Then youll be safe .

Quote

But done right, they are just fine.

Cost , weight , or expense ( in time etc , but then they do have accessability .)

The WEIGHT is dead minimal as a % ,

CARBON & KEVLAR thrown in the interface you could have it keyed together at no cost !? in ridgidity . Its when you WANT flexabilty ( bend like a willow , Son . ) that it gets trickier .

The Continuity of deflection under load kan ceep you awake , at Knights .

https://aviation.stackexchange.com/questions/34097/how-can-we-operate-wing-bending-tests

Technically , some elasticity will cope better in gusty turbulent air , lkike a Detroiter . IF its ' controled ' or designed in , not unbridaled . Like flexable yacht masts . a PERCENTAGE . Though weve all seen ' cresent ' ed wings in the wind ? ? .

Air Ministry . · « **Reply #44 on:** August 23, 2023, 10:02:26 PM »

You wouldnt want those battery packs jumping round in there ( in the wind ) Shock loads - like a hammer . No Give in the mounting & the force is directly absorbed , but let it start moving and theres a sudden halt - jump - in the pattern . Just a thought .
Akin to a slide hammer or suchlike . Where if it was welded up ( the slide hammer ) it wouldnt . If you get the drift . The Thump of a loose battery pack , would be a shock load . Way more evere than its ridgidly mounted stress .

Dave_Trible · « **Reply #45 on:** August 24, 2023, 07:08:37 AM »

Quote from: Paul Walker on August 23, 2023, 09:20:22 PM

You simply give up some structural integrity for the take apart ability.

Dave

Maybe you do. But done right, they are just fine. I have many that will attest to that.

Yes you have! The last couple I've built have stayed together, but it took a learning curve to find the failure points.

Dave

Dennis Adamisin · « **Reply #46 on:** August 24, 2023, 07:53:11 AM »

Quote from: Joseph Daly on August 23, 2023, 04:25:43 PM

Well, when it rains it pours for me!!!! Today I took out my NATS plane to practice for the Mass Cup. On the 6th flight of the session during the 2nd outside square the wing folded and all I could do is watch the plane try to fly and I thought maybe I could save the prop by putting in the grass. Well it had other idea and started climbing to the top of the circle and all I could do is watch as it pounded into the pavement!

This one hurts as it was one of my best planes and it is the one that got me into the top 5 in 21 and it won at Triple tree this year.

I am not sure why the wing folded yet. It was pretty windy today and this plane has been flown it some real bad wind in the past. When I get some time I will look at to determine the failure. This one is a shame!

Geez Joe, remind me not to stand anywhere near you during a thunderstorm. Probably not a good time to buy lotto tickets either!

All seriousness aside, The leadout failure crash is scary because I am sure there are dozens of airplanes out there with a similar set-up that may be at risk. Although the leadouts had nothing to do with the 2nd airplane's demise, did it have a similar leadout arrangement as the first? If so, can you tell if it was on a similar path as the first with regard to leadout failure?

AMV · « **Reply #47 on:** August 24, 2023, 10:27:41 AM »

Quote from: Joseph Daly on August 23, 2023, 04:25:43 PM

...On the 6th flight of the session during the 2nd outside square the wing folded and all I could do is watch...

Joe, if you need a spare wing, let me know! This one is still very much intact. For me this also happened when coming out of the 2nd outside square, I was just too slow and could only watch it plow the earth...

-Andrey

Ken Culbertson · « **Reply #48 on:** August 24, 2023, 10:37:34 AM »

I have always advocated some degree of flex in a wing so that the full force is not placed on the center section. I have never had a wing fold. Until Endgame III I have always double planked the center section of the wing. This one is not and I am concerned, I turn very tight corners. I have been told that with webbing between the spars it is not needed. With the thin molded turtle decks, pipe tube cutouts and tiny fillets, I personally think we have created a weak spot at the center of the wing because the fuselage no longer has the crush strength of the blocks we used to use and the stiff wings (a Warren Truss doesn't flex much) don't absorb the stress the way they used to. It is not like this is an epidemic, failures are relatively rare but when they happen unnecessarily due to our pursuit of super light planes, it makes me wonder if that half ounce saving is really worth it.

Ken

Dave Hull · « **Reply #49 on:** August 24, 2023, 05:51:16 PM »

Ken,

A few thoughts:

Even if you have a "flexible wing" the full force is always reacted in the wing center section. This is easy to understand for quasi-static flight loads. The only thing you might gain by intentionally building a "soft" wing is that sharp buffeting loads are absorbed over a slightly longer time period as the flex occurs, potentially reducing peak stresses.

As to the stiffness added to the wing in bending from the fuselage tube--don't count on much. (I assume everyone was hollowing out the solid fuselage blocks.) The fuselage is not the right shape to provide much additional help. If the fold failures you see are occuring at the side of the fuse, then the fuse was assisting (and perhaps a stress concentration was built in.) If they are folding where the center section planking ends, then we need to avoid that abrupt change of section modulus. Ultimately, putting the shear webs into the spar is in exactly the right place to directly help. And, if you used 5/16" square balsa spar caps, and felt they weren't up to it, then glue on some .007" carbon strip facing the inside of the wing before you glue in the caps. It doesn't have to go all the way out to the tips, but at least run it out past the landing gear bays. It adds weight, but also adds strength and confidence that you will have structural margin....

I'll take your other question as rhetorical--no one wants a wing to fold because they were overly zealous about saving 1/2 to 2 ounces of weight depending on the model size. Certainly not if it is relatively new and isn't oil-soaked or damaged from a previous incident.

Dave