twostroker

My Feedback: (37)

Is it common to have the whole wing flutter on a beginner sailplane, I'm not blaming it on the plane but it is a Hanger 9 Aspire. The wing fluttered at the bottom of a 100- 150' dive to make a fast and low fly-by, so I was obviously too fast. But I wondered if this was common with a beginners type sailplane. It lasted for only a second or two and the plane landed safely so there was no damage. And yes it was the wing you could see the whole thing fluttering.

rogerflies

My Feedback: (3)

Flutter is a potential problem with any wing that isn't built with a sheeted D-box leading edge. The wings that depend on the covering material for torsional (twisting) rigidity just aren't meant to go fast.

Flutter can cause weakening of the structure, even if it doesn't break the first time it happens. Fly the plane like it was intended to be flown and avoid the high speeds.

Roger

Landi

My Feedback: (1)

Hey Roger

If you want to do low passes buy something suitable for it.

Dont try to do it with planes like the Aspire, Bird of time and others from the same family. Those planes are floaters and are not meant to go fast at all.

I think your where luky tha the wing did not colapse when you pulled out of the dive. So be carefull and fly the way the plane is designed to.

Saludos

Thomas

R. Carver

Oooh, Thomas, don't lump the BoT in with the weaker planes. I've done many a speed run with mine and built right it'll take it. Remember, it WAS an F3B model at one time

AcintSpec

2S:

Yes, you can get the Aspire to flutter. Have seen them flutter on occassion while launching, heavy foot on the pedal. It is not uncommon to see the wing break on an over agressive launch or zoom attempt. They do great at the lower speeds though. My experience with the Aspire has shown the wing at times need a little extra adhesive around some of the glue joints on the spars. Both of my wing failures occurred when the shear web finally worked the rest of the way loose from the spars. I prefer the method of having the shear web between the spar, much like an I Beam rather than in front of or behind the spars. Seems to be a little stronger IMHO.

R/Gene

BMatthews

Ditto. You just crossed the line of what was expected of that design. It's not just the Aspire either. Any similar model will have pretty much the same charactaristics.

Side note. I've even seen a Saggita 900 do the wing flutter during a long high speed dive. It was fluttering so much that it was like it hit a brick wall it slowed down so fast. Once below a much lower speed from where it started the flutter stopped and all was well..... other than the look on the owner's face that is. The Saggita shares the same D tube construction as many other designs so you must realize that any model will flutter when pushed beyond it's limits. It's just that in some cases the flutter limit is higher than the terminal velocity.... Unless you start adding ballast then even those might offer up a nasty surprise.

LEDZx

Just on the topic of flutter, I have recently built a Mig7 slope soarer out of correx ( not quite the same as a glider), but on the first flight last weeend i noticed on landing, when I did a tight turn in front of my face, that there was a frequent poping sound. I did another turn about 2m infront of myself and then realised that it was the whloe rear stabiliser( horizontal and elevator) fluttering, even though it was a high G turn, why would the elevator flutter( and it had full deflection, which i would imagine would make it more rigid to bending.
Any thoughts appreciated
LEDZ