Myth: 1 G barrel rolls are impossible.

Dudley Henriques wrote in
news:2007061123170075249-dhenriques@rcncom:

On 2007-06-11 23:02:16 -0400, Bertie the Bunyip
said:

Dudley Henriques wrote in
news:2007061122543716807-dhenriques@rcncom:

On 2007-06-11 22:26:31 -0400, Bertie the Bunyip
said:

Dudley Henriques wrote in
news:2007061122074775249-dhenriques@rcncom:

On 2007-06-11 21:42:18 -0400, Bertie the Bunyip
said:

"Robert M. Gary" wrote in
oups.com:

On Jun 11, 12:51 pm, Mxsmanic wrote:
Jim Logajan writes:
Myth:

It is impossible to perform a barrel roll such that the pilot
feels exactly 1 gee of force perpendicular to the floor of the
cockpit.

No maneuver that involves a change in altitude can maintain
exactly 1 G along the net acceleration vector (including
perpendicular to the cockpit floor). This is not a myth, it's a
fact.

The only roll you can perform that does not involve more than 1
G of net acceleration is one that involves no change in
altitude, such as a roll precisely about the longitudinal axis.
But no roll that maintains the net acceleration vector
perpendicular to the cockpit floor is in this category.

A barrel roll is not about the longitudinal axis of the plane,
that is an aileron roll.


Nope, a roll about the longitudinal axis of the airplane is a
slow roll. actaully that's not entirely correct either since a
perfect slow roll follows a perfectly staight line, which means
the axis of the aircraft must change in realation to the line of
flight throughout. A slow roll is, hower, a one G roll. The 1 G
should always point earthward, though.


An aileron roll is actualy not dissimilar to a Barrel roll in
flight path.


Bertie

Actually Bertie, think about it for just a moment. In a slow roll,
you do indeed roll the airplane on it's longitudinal axis but the
roll line isn't exactly straight.


Not for competition. You're judged by the line you fly. Mind you,
if you can make it look like you're not pushing the nose all over
the place, all the better.


Bertie

Therin lies the "art form" :-) Kirk Brimmer, solo for the 71
Thunderbirds told me the hardest thing to do for him in the entire
show was to make his super slow roll look flat from the ground.
Never flew competition, but I agree totally that making the line
look good is the whole 9 yards.

Yes. In fact, going vertical, it's expected you make a drift line to
compensate for wind. So if you're doing a vertical roll, you must do
it off the veritcal to make itlook good for the judges.

This is also a serious problem in demonstration flying. You're nearly
always dealing with a crosswind because the show line is fixed and
crowd positioning is critical to meet waivers. In the Mustang going
vertical, the torque changes are horrendous as you bleed energy on the
up line and require copious amounts of rudder and some opposite
aileron to hold the line. Throw in a crosswind and you can really have
your hands full on occasion
:-)

Not that I've ever competed in anything that would go vertical long
enough to make a difference!

You and Duane Cole! I honestly think it was the constant extension of
the vertical line brought on by the influx of the higher powered
Pitts' and some others that did him in with his clipped wing T Craft.
What that man could do with that little puddle jumper had to be seen
to be believed.

Still the best aerobatic pilot I've ever seen..I've sen him maybe ten
times over the years. Just brilliant..

Funny thing about competition judging is inverted spins. The pilot
does the spin to the left and all the "new" judges put it down with
a nice Aresti figure and a notation to the right :-))

They even confused me from inside.

You TOO huh??? Count me in on that one. The first one I got into was a
botched multiple outside snap in the Pitts. Took me several turns to
figure out what the hell was going on. I've always recommended to acro
pilots that they install a T&B in their airplanes. The needle shows
the spin direction either erect or inverted which on occasion can be
"quite useful" :-)

Wel, in everything I've spun inverted, if you just push the rudder pedal
that's sticking up you'll come out.
I'm sure that there are exceptions though!




Never Spin a Stearman (the 75 in case we have any nitpickers here) to
the right (pilot's perspective) cuz you'll get a face ful of fuel..

Got a few hours in the 650 way back when. Man, were those pedals wide
apart!! :-))

Yes, good airplane for exploring aerobatics for th eneophyte, though.
Unburstable, except for that prop thing.