It was one of those perfect days that you dont see very often, no wind and perfect tempature. I started flying my Funtana x100 just like always slow and having fun. Well I just got done doing a snap roll when all of a sudden it went to full throttle. I knew that I could not fly the x100 at full throttle with the YS 1.10 so I decided to go verticle, that way there would not be as much stress on the plane. Well after a few seconds there was a really lound noise and then silence. At first I thought it was going to be just like any other dead stick but I realized I didnt have hardly any controll. My first thought was I blew one or more surfaces off. Well after fighting it all the way to the ground for a super soft touchdown about 10 feet from the edge of the runway. I was pretty happy untill I walked up to the plane. I realized there was no motor! TALK ABOUT TAIL HEAVY!!! I took it back to the stand and looked it over. The cowl was destroyed the motor mount failed but other than that not a single scratch on the plane.

The field is pretty much surrounded by swamp land all the way around so my hope was the motor didnt fall in there. One of the club members saw something fall and new a gerneral area to look. We probably looked for 30 mins or so with no luck. I thought there went a $400 motor. We gave up and started heading back to the club house. All of a sudden we saw the motor right in the middle of a cleared spot in the field. I was so happy. I then realized how lucky I was.

There might be some minor damage to the motor but not to bad the prop was no were to be found so who knows what really happened in the first place all I know is I got all my stuff back and pretty much in one piece.

FYI: The field looks really bad because it has been raining here in central Arkansas for weeks, so it has not been cut!

I have to put the pics on a couple different post, says the files are to large.

rc-plane

More pics.

rc-plane

looks like a simple fix, just order a new cowl and put a new engine mount on it.. one question though, did you balance the prop that was on there? i can't imagine that engine mount just snapping like that, that is crazy! well, nothing to do but put it back together and fly her!

is the throttle arm set like most motors so that the arm rotates forward to go to full throttle or has it been turned so that full back is wide open? Trying to understand why the throttle went wide open...

Glad you got it all back - good save on the model aswell![8D]

cheers
Rick

I have know clue why it went wide open. I am going to buy a new servo just in case. There was some little bubbles in the mold probably cant see that in the pic. I should have it back together before long.

Just to let everyone know - rc-plane is a really great pilot. I can proudly say that he was one of my "gifted" students. I was able to solo him in 8 flights, not 8 flying days, 8 flights. I remember the 1st time I got him flying- he and his Dad stopped by the flying field to watch and I just happened to have a trainer there for a test flight. I invited him to come and fly on the buddy box and the next thing I knew, he was committed. Now, he out flies me! He is also becoming a very good instructor pilot. He has already soloed his first student in the dead of winter. Just goes to show you that if the plane is still flying, don't panic. Try to get it down in one piece. Good going.

I was having trouble with the stock mounts on my SSE breaking like that (Saito 82), but I managed to catch it before both halves broke. I now poly glue and screw brass strips along the length, and haven't broke another. I also modified the stock mounts to accept J-Tec snuf-vibe bushings. Made a HUGE difference in the vibration. Nice save on your plane, I'm amazed you managed to get her down.

As a guess, I'd wager the throttle went to wide open because the mount failed on the same side as the throttle linkage...allowing the motor to rotate/slide in whatever direction necessary to open the carb.

I've seen a good friend toss a motor off of a Funtana 90, and saw the argument he had getting it back down. Sounds like you did a FANTASTIC job of saving that airplane. Kudos!

Cool story rc-plane. I'm trying to understand what happened to the prop though. It appears that the prop nut is still on the shaft, so either the prop shattered in flight or when the engine struck the ground. The blades didn't end up in the ground where the engine landed did they? Was any of the prop left around the shaft? I wonder if one blade fell off, during the vertical climb, causing a severe imbalance that broke the mount. Maybe the other blade then struck what was left of the mount or maybe the landing gear, and broke off. Nice save anyway.[sm=thumbup.gif]

Thanks for the comments. What you see on the motor is all there is. There is no part of the prop anywere nere the landing spot. I really dont know what happened. I know I will be using another type of mount...Dont know what kind but deffently getting a new one.

I exploded a prop on take of this sunday.
Full throttle and just when leaving ground, bam... hi pitch rev and then silence.
This prop was an NIB old TF 11x7 it must have been 30 years old.

So I think that might have been your problem, a damaged prop that faild in air.

Hope you get it back in the air quick again.

Take care.

That's what I'm thinking also. But, if the prop exploded, I'm guessing it did so before the engine mount gave way. So how did the mount break? I would think that once the prop was gone, that would relieve the strain on the engine mount. Unless again there was a momentary imbalance that lasted long enought to break the mount. Sorry, I get hung up on things like this now and then.[&:]

A club mate asked me to try out a trainer he made some modificatins to. I had a similar incident with it when the throttle froze wide open. I circled that plane around and around the field, allowing it to gradually climb, for close to what seemed an enternity. Luckily nothing happend. The tank ran dry and I was able to make a gentle dead stick landing.

from what I can see in the pics it looks like the throttle side of the mount broke last and since you said it went to full throttle the prop may not have exploded right away but instead warped during the vertical. I have had some plastic props off of toys that I stuck on my 30,000 rpm rotary tool and the pitch of the prop causes the tips to bend forward slightly. This often causes the pitch of the prop to be disturbed for a moment increasing the rpm's. After a few rounds centrifugal motion takes over and the prop straightens out. the loud sound you heard may have been the increasing rpm's of your engine then upon the staightening out phase the prop may have broke. If my theory is correct the increased rpm's and the propellers warping caused a lot of vibration and that is what snapped the engine mount.

This all was kind of why I was asking if the throttle is rigged to WOT backwards or forwards. If backwards and the mount broke (stress?) and the motor moved forwards then you have WOT, the 2nd half breaks and wham! the motor tears out.
just a thought...

cheers
Rick

The prop got broken when it hit the cowling due to the movement of the engine which was shaking inside the cowl, the engine stalled because one part of the mount was already broken (servo travel was useless) and maybe part of the prop broke apart by hitting the cowl, you know what happened next.

Congratulations for saving your plane and as a suggestion I would tear apart the engine and clean it before any attemp to run it again.

Best of lucks.

Alfredo.