"Bob Moore" wrote in message
. 122...
Dudley Henriques wrote
I've done barrel rolls deep in the left side of the envelope using
hard inside rudder in high performance jets that you would swear were
snap rolls!! :-))

Dudley, what source do you use for your definition of a "barrel roll"?

Bob Moore

Well, after teaching them and doing them for fifty years, I guess I could
use myself as a source. I know of at least one major aviation magazine and
one major book on airshow safety who have used me as an aerobatic source
anyway :-)
That pushed aside for obvious reasons of propriety, your IAC source is fine,
as is your good Navy training .
Remember Bob; the military usually teaches barrel rolls in the classic
format for primary, which is as a precision maneuver using specific points
of reference to be obtained during each segment of the maneuver. You usually
don't get into variations of 3 dimensional maneuvering until lead in basic
BFM and ACM.
I also probably taught barrel rolls to primary aerobatic students the same
way you learned them in the Navy. Advanced maneuvering is another matter.
Just remember when discussing barrel rolls; there are only two ways to move
an airplane through three dimensional space. You can maneuver it using a two
dimensional maneuver through three dimensional space, or you can maneuver it
using a three dimensional maneuver through three dimensional space...and
that three dimensional maneuver is a barrel roll, no matter how tight or how
loosely you fly through the roll. Any roll, no matter how it's done, that
moves the airplane "around that barrel" is a barrel roll. If you want to do
it using the points system with the nose pointed exactly 90 degrees to the
entry heading at the inverted point, that's fine. That's a barrel roll. If
you want to pitch into the vertical line, and roll off that lineputting the
pole in the left or right corner of the cockpit winding it through like a
cork screw, that's also a barrel roll. As long as you have three dimensions
in play during the roll, its a barrel roll.

I seem to remember the Navy defining barrel rolls in the J Stage of training
in the F9F-8 Cougar as a shallow dive at about 95% to 350kts; level off and
trim; then roll the airplane around a point 45 degrees off the nose to
either side; initial acelleration to about 3g's; the nose should reach a
point about 45 degrees above the horizon at the 90 degree point; the roll
rate was adjusted to achieve a 90 degree heading change at the 180 degree
point inverted; ; you looked for about 180 to 200 kts at the top inverted
where you were looking at about 1+g if you did it right; as the nose came
through the back side, you adjusted the roll rate to nail level flight again
at your initial entry speed of 350kts. You would play the g from the initial
3 during the entry down to the 1 at the top, then play back in the 3 during
the recovery back to level flight.

This is a good way to teach a barrel roll, adjusting the speed and roll rate
a bit of course for something like the SNJ :-))

But all this dosen't change the fact that a barrel roll can be done much
tighter than this and doing it that way dosen't change the fact that you are
doing a barrel roll :-))

Dudley