My knockaround Ultra Stick 60 with a saito 125 and an 15x10 prop....is no more.....

It was finnaly to the point were I was content with the valves, idle and high speed of the saito and started to teach my dad on the plane.
He was already taking off and was able to control it well in the air. I made him fly most of the time at about quarter throttle, but that was still too much when he started a high speed dive from a high altitude and the wing broke off in the air and fell to the ground about 2 minutes after the saito/fuselage nose dived. It took us nearlly two hours to find the engine and fuselage, but an hour more and we just gave up looking for the wing.

wow!!![X(] lol how fast was that thing going. i wish u had a video of that. well, a least u found the engine and most of the servos.

Sorry to hear of your loss.

However, there is a lesson to be learned. Any airframe can be overstressed, especially an ARF airframe. Then add in twice the rated engine...

Any time you hang way more weight on a structure than it was designed to support you're asking for trouble.

Overpowering isn't the only mistake. If power was only an aerodynamic deal, it wouldn't be half the catastropy it is.

What also happens, and is almost universally ignored, is that the airframe wasn't made to support the weight of those larger motors. And it wasn't only not made to carry the weight, but the stress that weight causes when the airframe is dealing with what would have been just a few more Gs.

Most designs are adequate for the expected weight of the design engine. The structure was sized to carry the weight and carry it through the aero stresses.... the G forces too. But put twice the engine size on the nose, and go pull those Gs. And add in the fact that the airframe can now pull even more Gs than originally the structure was designed for......

Heck, think about landing. The airframe isn't being aerodynamically stressed beyond expectations, right. But hit a little hard and what does that do? G forces from shock.... now are outside the envelope.

Ya, with that engine on that plane I think the plane was destined to come apart any way, just a matter of when!

Weight is not an issue. This engine only weighs 1 oz more than specified engine weight (assumming its designed for a 61 2s). Power wise, well thats a person opinion too. My H9 60 sized mustang with a Saito 100 seems underpowered (falls off the top of a 100ft loop). My friend has the same plane with a 61 2s and he flat kicks my butt.

Bottom line is that no plane can withstand a hi speed dive no matter what engine you have on it...

Well, get dad back in the air and glass the wings together this time or add better strength to hold them to the fuselage. I have had some high speed stiks and it should be able to handle it.

I was teaching my boy during his high school years but now he is finishing college and very busy. He'll be back on it someday and I'll still have the stuff to get him back in.

I also feel that a 60 size Ultra Stick and a 125 is a decent combination if you strengthen it up in the right areas. Clean up the engine and get another one and move on. Without being their and seeing it all, sounds to me that it was a structural thing that could have happened with a 60 size engine on it.

Well, today my dad told me had been going full throttle (I did'nt even notice) and I thought he had control of the plane and did not take it away from him. AS a forethought the engine was giving 8500 ground rpm on that 15x10 and that is at least 80 mph but in a dive that is probably close to 100mph on the ultra stick that is really not made for speed, well maybe if I had reinforced the wing dowels with something it would have withstood a little longer but....hope I can find the wings since I have a new fuse at home.

It looked great the wing just rolled off of the plane and didnt stop rolling till it was somewhere near the ground when we lost sight of it. at least there wasn't too much damage to the engine just the valve covers and the valve guides.

Thanx for everyones interest.

zayzay1,

If you need a set of tail feathers for the new Stick, I have a brand new set just laying around. I no longer need them. PM me if interested.

Jesse

Teaching a teenager to drive in Richard Petty’s racecar would also be a disaster. You know that inexperience and speed would get him in trouble.

Bill