aerobatic fuel squashing

[lucaperazzolli]

With 15 Us gallons for each tank, I play some aileron rolls.

Every time I start my full aileron movement I feel a 'double time' movement in the same side of the roll (I hope that is the fuel forced into a quick movement).

A slow motion roll give me no problem.

Any idea or experience to share with me ?

[DEWATSON]

Does it feel like aileron bump?

[N733JJ]

This is pretty common with full deflection ailerons in RV's. I believe it is actually a buffet from aileron stall but I haven't tufted it to be 1000% sure.

I bet Kevin Horton can come up with a proper explaination.

Scott A. Jordan

[Toobuilder]

First thing I thought of too. The first time I did a full deflection roll with the -8 I felt the burble too.

[Mel]

It's aileron buffet. Try 1/2-3/4 deflection. Much smoother. And almost as fast.

[mike newall]

Yep - watch the aileron - it is interesting !!!!

[flyvans.com]

Definitely nothing to do with fuel.

And happens in all 2-seat rv's that i've flown, 6,7,8.
it's definitely aerodynamic from the ailerons themselves, however i'm not sure whether it's caused by the up or down aileron...

also, we found the best / most agile / good control feel speed is around 120kt, right near the official maneuvering speed of 123kts.
so if we want to do some sightseeing / orbits and such, we reduce to 110-120kts first, plus you get more time to look at the things on ground.
we also start rolls mostly around 120, where that buffet is not so pronounced.
anything above is just for cruising, descent and loops (140kts).

rgds, bernie