"Big John" wrote in message
...
Dudley

Can it be said?

In a Barrel Roll the ball starts centered and stays centered
throughout the roll until aircraft returns to straight and level
flight and starts some other maneuver.

If you are good, you can fly a barrel roll center ball. This requires a near
perfect blend of all controls and is the right way to do the classic BR.

In a Slow Roll (sometimes called Point Roll) the ball starts centered
and is then never centered except momentarily when bird has rolled 180
degrees and is inverted, until completion of roll and return to
straight and level flight?

Well...almost :-) You might lose the center ball as you pull to the roll set
point but in theory it should remain more of less centered up till roll
initiation. Immediately after you initiate a slow roll, you will lose a
center ball as all control input through a slow roll is done in a constantly
changing cross control dynamic. In theory, you should have a doghouse ball
passing through the exact inverted point, but what actually is happening at
this point is that you will be changing rudder to regain top rudder on the
back side, so the airplane will be in a state of transition even through
exact inverted.
Personally, I never used a ball at all in aerobatics and I don't recommend
using a ball to other aerobatic instructors. One of the benefits involved in
learning to fly acro is that you learn to judge maneuver quality with your
eyeballs on the nose attitude outside the airplane . All positioning is
eyeball related and any unwanted yaw should be immediately apparent by
watching the nose.
I discourage ball use even in primary students, and get their heads outside
where it belongs as soon as possible.
All pilots should learn as soon as possible to judge turn quality from nose
attitude behavior.
I know many...many aerobatic pilots who take the ball out of their airplanes
simply to save the weight and space the instrument takes up on the panel.


Rolls are easy to explain face to face in briefing using hands or
models and demo in air, but over Internet the nuances of English make
it difficult.

This can be quite true.

Dudley Henriques


Big John
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On Fri, 21 Jul 2006 14:43:10 GMT, "Dudley Henriques"
wrote:

Ron;
I think what might be happening here is that some folks are defining the
roll from the set point rather than from level flight. It's true that any
raising of the nose from level flight will require more than 1 g, but once
at the set point and initiating the roll (aileron roll) you can unload the
airplane all the way down to 0 g if you like right up to the backside
recovery to level flight, where the g of course has to be returned.
Dudley Henriques

"Ron Natalie" wrote in message
. com...
Big John wrote:
Andrey

As has been said in all the posts, the short answer is NO. 172 is not
certified to do barrel rolls.

However I can barrel roll a 172 only pulling 1 G which puts no more
load on airframe than straight and level flight. I have thousands of
hours to back up my statement.

No you can not.

It's not possible to even start the roll without going greater
than 1G.