Hey guys i just wanted to make you awaare of what recently happened to me> First of all i crashed my first avistar that had a 40 LA on it And totaled the plane and the radio. Then i bought a new avistar arf and a 46 FX engine. I thought i would buy the engine that was good so i could use it in future planes. I found out all too quick that that engine was too powerful For my plane. After a few flights i got into a downward dive maybe only 30 degrees and pulled a little bit up and whatched as my wings snapped and my plane lawn darted into the ground creating a 4 foot crater. After i examined my plane i realized that it wasnt a bad glue joint but the spar actually snapped in half. The moral of the story is....Dont fly an avfistar with a 46 FX At full throttle.

I have been having similar problems. WHen I am at full throttle the plane becomes very sensitive. I habe my throws set up for about 1/5 inch and it sill goes nuts at full throttle. If I fly at 1/2 to 3/4 throtlle it behaves but anything more and it scares the pants off me.

You might add don't fly ANY plane at full throttle and "roll and yank" as it is likely to snap the wings.

For those who don't know what "roll and yank" means: Beginners have a tendency to pull (give up elevator) when they get into trouble. In making a turn the plane is rolled and then an excessive amount of elevator is given and the g forces start to work on the structure of the airframe. It might not break the first few times however the joints will weaken.

The soultion is to learn to use the left stick > both the throttle and rudder to make your flying more enjoyable and safe.

EXCAP232

Ross,
Check your Personal Messages. I just e-mailed you about the problems with the wing. If you need any other help let me know.

Paul

thankx and i was just warnin yah i think im gonna get a more sportier plane like a 4 star 40 my instructor said i would have soloed that day if the wiong haddent broke. i had already taken off flown and landed with out his correction but i never officially soloed. Thankx for the input

Hey CanopyFX,

did you ensure that your plane was balanced? That could be a symptom of "tail heaviness". Check your instructions on how to balance the plane and where the balance point is.

Might not be it but worth checking

Bob aka Nuker

Yes my plane was perfectly balanced

ok, other options could be to ensure the thrust line is accurate for the engine, that the tail is lined with the wing...... ahhh the options.

My family has had two Avistars; both with .46 fx's (both Mrs. Nuker and myself) I was always adjusting it (with each repair as well )

Bob aka Nuker

Probably if you bring the cg slightly to the front, it might be less sensitive. Worth a try. I remember from Hobbico's website that the avistar is rated up to .46 So, it is not overpowered...........

Your problem is not the size of the engine !!!!! What happened is that when you dove and then pulled back, the force stretched the rubber bands, letting the wing rise above the wing saddle, and thats when the wing root gave way. With a 46 FX, you should have had at least 14 to 16 bands in place for that dive/climb. Go even 1 step further and modify the plane for wing bolts.
In our group, we have determined the AVISTAR to be the best funflyer/trainer/windflyer on the planet. The FX 46 is a nice upgrade for it. Don't use old rubber bands eighter, and keep them in a baggie with a little talcom powder to absorb the fuel/oil which breaks them down sooner. Dennis (Red Bluff)

I am curious.
The joiner of my Avistar was a metal rod. Was yours wood?

If you buy just the Avistar, it came with a wood dihedral brace (wing-joiner) The guys who bought the whole kit (radio, engine etc) had those metal rods at each end; though as far as I recall, there was also a dihedral brace (piece of plywood about 6 inches long like a really open V. You have to epoxy two pieces together to make it thicker.

The metal rods weren't in the new kit I build for my buddy though it's possible all the newer kits have them now.

Just remember, despite what seems to be in the instructions, don't just bolt on the tail surfaces, use some epoxy

Bob

The Avistar Select had metal tubing, The Avistar ARF had wood dihedreal brace. In eighter case, you should always epoxy the wing root. Don't be stingy with the epoxy......It's alot cheaper than a new plane, and never use less than 12 rubber bands.
Dennis (Red Bluff)

I guess that is why my plane had the rod (select) While I didn't glue the halves together, I did glass them together.

Im with flatbeddennis, the engine and the plane are not the problem.
I fly a Hobbico Superstar with an O.S .46fx, My skills are still very basic but I have done dives and pull ups without any problem. One thing is to make sure that when you enter a dive that you reduce your throttle to almost nothing. When you pull out do so SLOWLY adding elevator.
If you slam the plane around then you are of course going to have problems. Trainers are not designed to be aerobatic planes.

While the avistar does have an semi-symetrical wing if you slam it around it will break.
I watched a Avistar fly this past weekend, the guy climbed the thing almost out of site. Then proceeded to enter a dive and came fairly low in my opinion. He pulled out with a smoothe approach and had no problems whatsoever. He did actually slam the plane a little more than what I thought was normal as I watched him fly.
He had no problems though.

The Avistar is a great plane and can handle plenty with a decent flying style. The O.S .46FX is quite perfect for these trainers in my opinion, however some may feel more comfortable with the 40LA.

Dbow

Hi,

I too have an Avistar equiped with an OS .46FX.

This is my first plane, bought new, as an ARF. It came with a 3-piece wooden wing joiner and has a wooden main spar (no metal seen while building).

The instructions clearly say:
Note: when performing the following steps, be sure to use a sufficient amount of epoxy to form a complete and solid bond between the plywood wing joiner and the two wing halves. This is the most important glue joint on the entire airplane.

Ross stated that it wasn't the wing joiner, but the main spar.

Not good! (in my opinion)

After reading all of these posts on this web site, I may never get this thing off the ground... now I'm wondering if I should use nylon wing screws like I've seen on other airplanes.

I'm ready to break-in the new .46 and get it started for the first time, but now I'm also wondering about the "thrust factor".

Maybe I'll just take it up - see what happens - and make modifications to it later.

I suppose in the (almost) worst case sceniario, I could buy a replacement wing set and reinforce it with metal rods... but I just wanna' fly and have fun with my new found pals!

MacAir (local to a few)