In article ,
vincent p. norris wrote:

Or the corkscrew motion of an aileron roll must provide enough "outward"
(normal) force to counteract the downward force of gravity.

I think I understand what you're saying, Hamish. It may depend on the
airplane. An SNJ doesn't "corkscrew" very much. It would hardly be
enough to provide positive G in excess of 1.0.

Well, the *whole point* of a textbook aileron roll is to maintain
positive G's -- not 1+ G's, but *positive* -- all the way through the
maneuver, regardless of whether you do it in a Pitts or a puny Aerobat
(the Pitts is a lot more, erm, exciting in this respect :-)).

The maneuver starts with a pullup...

It does start with a slight pullup, but then then back-prssure on the
stick is released, to produce what approximates a zero-G situation.
(Don't you do that in an Aerobat?)

The textbook aileron roll in an Aerobat starts with a shallow dive to
120 KIAS, then a smart pullup to 30 degrees pitch, then a quick
simultaneous full-over on the ailerons and neutralization of the
elevator until pullout. Apply rudder as appropriate... The Pitts is
pretty much the same, but at least with the constant speed prop you
don't have to spend so much time obsessing about the throttle.

I thnk the best description of an aileron roll is to call it a zero-G
maneuver. Not *exactly* zero, to the tenth decimal place, but close to
zero all the way around.

In no plane I've ever done an aileron roll in is the G force "close to
zero all the way around". In fact, it's close to 2G's at two points in
the maneuver (pullup and pullout), and it's probably around .5 to 1 G
over the top.

and that pullup is never really lost

I don't understand that. I need to use some right rudder after
passing the half-way point of a left aileron roll, or I'll end up
with the nose pointing down about 20 degrees.

Remember, half way around your altitude is still quite a bit higher than
it was when you started the maneuver....

(unlike the slow roll, which can result in negative G's in many aircraft).

I don't understand that, either. You're saying there are airplanes
that can perform a slow roll without experiencing negative Gs?

No I'm saying that true textbook slow rolls result in negative G's (and
are nearly impossible in an Aerobat, but never mind...).

Hamish