Great Planes RV4 40 flutter
 

Just began to disasemble my .46 sized RV4. Have flown it for 3 years with a Magnum .46 and flaps. I never fly this plane at full throttle (except for this time), it is very quick for such a small motor. Staright and level on a full throttle pass the stabilizer broke and began severe flutter. I was able to slow the plane down, drop the flaps, but the damage to the empanage was done. Landed wings level in a bean field with just some monocoat damage. Upon examinig the plane the vertical, and both sides of the horizontal stab were broken into. The canopy broke loose and took some balsa with it, and the elevator servo stipped its gears. Wheel pants also were damaged. The beans took their toll on the monocoat, but probably saved the airframe from a lot more damage. Be a quick repair project for this winter. Any one else have this happen? The control surfaces were nice and tight, not any slop. I quess I could have lost the elevator servo first and this started it all, who knows!

JEB[&o]

RE: Great Planes RV4 40 flutter
 

any loose hinges shown up in the aftermath?

RE: Great Planes RV4 40 flutter
 

When you get it all put back together, you might consider dropping some prop pitch. I don't know what you have been using, but it (apparently) is a bit too much pitch resulting in a bit too much speed, resulting in............ you get the idea! I like the Mag 46 and I have used it with 11X5, 11X6 props, and on a Pulse XT, a 12X4 with good results. The Pulse is a low drag airframe, and even with the 4" pitch prop, it is surprisingly fast.

Good luck with your rebuild.

RE: Great Planes RV4 40 flutter
 

Nope everything is tight. The plane was rock solid with great acceleration. I am wondering if I actualy broke a tooth on the servo gears and that caused the rest. Will most likely never know.

JEB:D

RE: Great Planes RV4 40 flutter
 

The plane was overpowered[:o]