I don't know what flutter sounds like, but an interesting sound that is usually made right afterwards sounds something like "oh damn!"

BLE,
More often than not, a still picture, movie or video is worth a thousand words. You choose the right flick to show flutter!

Thanks,
Ernie
Sailplane

I've got the same plane that makes the same noise you are talking about. I've flew it with that noise well over 100 times. It always happens in a high speed nose down atitude. Everybody said it was bad flutter. Well it isn't, its the front nose cheeks vibrating against the big long aluminum motor mount on that particular plane.


Ronnie

Which I would immediately correct so as not to happen again because...

- It may mask the sound of real flutter.
- It indicates excessive vibration of a part
- It will cause excessive wear of the cowling

Do you have anti-vibration mounting in place on your cowling? e.g. the tubing over the screws, etc.?

Ahhh, I ain't to worried about it. If I get tired of listening to it I'll just cut the cheeks off of the plane.

No anti-vib stuff on it, the plane comes with everything mounted solid on this particular model.
I fly this plane full speed every time its up with no problems at all. If it quits, it quits. I've been wanting to put that engine in something else anyway.

Ronnie

I've actually had to epoxy the two wing halve back together twice already. I guess the stress has been breaking that bond. However, I love screaming down the runway shooting the plane straight vertical, then a quarter turn and watching it rocket into the sky. This particular trainer has a thick metal rod in the wing, so perhaps that is holding everything together. I'm building a Venture 60 kit currently, and there is no way I'll be attempted some of the same things I do with the trainer. The trainer is built like a tank compared to the Venture. There is probably twice has much wood in the trainer. The wing ribs are over double the thickness of the Venture.

Thanks Ronnie. Those cheeks do flap quite a lot. Even while on the ground, I'll throttle up on the test stand and the cheeks violently clap. I'm worried that one of these days, the fuel line from the high-speed needle valve to the carb is going to come off while in the air. I can see the left cheek actually hit it the fuel line.

I've also had some problems with screws coming loose on the engine mount and the engine back plate. There must be a lot of vibrating going on up in the air.

Hi, My Four star 120 with a 25cc toro suffered from flutter last week. I went straight up with it until it couldn't climb anymore, pulled the throttle down came straight down with it and both ailerons fluttered!! It sounds like the trailing edge of a kite flapping on a windy day. I lost control of both my ailerons. So I had to land with the rudder! Found out one servo stripped and the other servo mount broke loose from the aileron hatch. I was lucky to land it in one piece. I will now beef up the aileron hatch mount and use metal geared servos. Lesson learned!

It sounds like this: (Ahem) "WAAAAAAAAAAAAAAAAAAAAAAAPOP!hissssssssssssssssCRA CK!"

Normally when you here it & say W T F it's T F L.