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.

On 2007-06-11 23:27:09 -0400, Bertie the Bunyip said:

Dudley Henriques wrote;

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.

That's what got Rollie Cole. Shame.
I miss the old days. I knew a lot of these people up close and
personal.Counting the people we knew on the jet teams and the rest from
the demonstration community, my wife and I have lost 32 friends through
the years to low altitude acro
Dudley

Dudley Henriques wrote in
news:200706112344078930-dhenriques@rcncom:

On 2007-06-11 23:27:09 -0400, Bertie the Bunyip
said:

Dudley Henriques wrote;

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.

That's what got Rollie Cole. Shame.
I miss the old days. I knew a lot of these people up close and
personal.Counting the people we knew on the jet teams and the rest
from the demonstration community, my wife and I have lost 32 friends
through the years to low altitude acro
Dudley

Yes. i've lost a few as well. Somehow I managed to survie it though!

I don't even like doing them at altitude so much these days. Except for
smooth stuff. A freind of mine has just got a Yak 52 and is going nuts
in it doing flat spins and what have you.. Gives me a headache just
looking at him!

On 2007-06-11 23:50:07 -0400, Bertie the Bunyip said:

Dudley Henriques wrote in
news:200706112344078930-dhenriques@rcncom:

On 2007-06-11 23:27:09 -0400, Bertie the Bunyip
said:

Dudley Henriques wrote;

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.

That's what got Rollie Cole. Shame.
I miss the old days. I knew a lot of these people up close and
personal.Counting the people we knew on the jet teams and the rest
from the demonstration community, my wife and I have lost 32 friends
through the years to low altitude acro
Dudley

Yes. i've lost a few as well. Somehow I managed to survie it though!

I don't even like doing them at altitude so much these days. Except for
smooth stuff. A freind of mine has just got a Yak 52 and is going nuts
in it doing flat spins and what have you.. Gives me a headache just
looking at him!

That's weird. I have a friend in Pa. in the financial business who's
into Yaks as well. (Gotta be careful saying this or PETA will be on my
ass here :-)
He has a 52 now and has just bought an 11. I believe he's trying to put
a P&W in the 11 as we speak.
Got another friend in Jersey who's LOA on Mig 21's.
I think the Russians might be invading after all :-)
D

Did I miss some context? Was there a debate about this? There are
videos on youtube of people doing barrel rolls with a cup of coffee in
their lap.

-robert

Ever watch the video of Our Resident Aero Commander Shrike Master Pilot pour
a glass of water/tea/lemonade with his right hand, while performing the
maneuver with his left hand on the yoke?

Bob Hoover is his name..

BT

"Bertie the Bunyip" wrote in message
. 130...
"Maxwell" wrote in
:


"Bob Moore" wrote in message
46.128...
My name is Bob Moore :-)

Just what is a barrel roll has been debated between "Big John",
Dudley, and myself at least twice in the past. It IS difficult to
describe without having a model airplane in one's hand and flying it
through the maneuver.

How come you don't seem to belive the following from Wikipedia?

Barrel roll
From Wikipedia, the free encyclopedia

This article is about the aerial sport. For the military operation,
see Operation Barrel Roll.
A barrel roll occurs when an object (usually an airplane or roller
coaster)
makes a complete rotation on its longitudinal axis while following a
helical path, approximately maintaining its original direction. The G
load is kept positive (but not constant) on the aircraft throughout
the maneuver, commonly not more than 2-3 G.

In aviation, the maneuver includes a constant variation of attitude
in all three axes, and at the midpoint (top) of the roll, the
aircraft is flying inverted, with the nose pointing at a 90-degree
angle ("sideways") to the general path of flight. The term "barrel
roll" is frequently used, incorrectly, to refer to any roll by an
airplane (see aileron roll), or to a helical roll in which the nose
remains pointed generally along the flight
path. In fact, the barrel roll is a specific and difficult maneuver;
a combination of a roll and a loop. It is not used in aerobatic
competition.

From:
http://acro.harvard.edu

The Barrel Roll is a not competition maneuver. The barrel roll is a
combination between
a loop and a roll. You complete one loop while completing one roll at
the same time.
The flight path during a barrel roll has the shape of a horizontal
cork screw. Imagine a big
barrel, with the airplanes wheels rolling along the inside of the
barrel in
a cork screw path.
During a barrel roll, the pilot experiences always positive G's. The
maximum is about 2.5 to
3 G, the minimum about 0.5 G.


Then would you label the roll that Jim has described here as a form of
aileron roll, instead of a barrel roll? Or do you think it is
possible to do a 1g aileron roll?

It's less of a roll than it is a loop.


In fact, that's how I used to teach it. Get a hula hoop, cut it and pull
the ends apart. you are now looking at the path of a barrel roll. A
skewed loop


Bertie

Would it be possible to maintain 1g in the seat if the "corkscrew" were
modified to a shape like an opening spiral, similar to a nautilus shell?
Maybe slip to the right while pulling the nose up to induce acceleration of
1g. You would continue this maneuver, gradually flattening the spiral as
gravity takes over the acceleration into the seat until you are again
straight and level. You would never "climb" against gravity at any point
since that would create an acceleration above 1g. Of course I guess this
isn't technically a barrel roll but my question refers to the possibility of
keeping a constant 1g as felt in the seat throughout the maneuver. Like this
crappy drawing as seen from behind:
http://home1.gte.net/res0f19c/dir1/spiral.jpg

TP

Dudley Henriques wrote in
news:2007061200011427544-dhenriques@rcncom:

On 2007-06-11 23:50:07 -0400, Bertie the Bunyip
said:

Dudley Henriques wrote in
news:200706112344078930-dhenriques@rcncom:

On 2007-06-11 23:27:09 -0400, Bertie the Bunyip
said:

Dudley Henriques wrote;

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.

That's what got Rollie Cole. Shame.
I miss the old days. I knew a lot of these people up close and
personal.Counting the people we knew on the jet teams and the rest
from the demonstration community, my wife and I have lost 32 friends
through the years to low altitude acro
Dudley

Yes. i've lost a few as well. Somehow I managed to survie it though!

I don't even like doing them at altitude so much these days. Except
for smooth stuff. A freind of mine has just got a Yak 52 and is going
nuts in it doing flat spins and what have you.. Gives me a headache
just looking at him!

That's weird. I have a friend in Pa. in the financial business who's
into Yaks as well. (Gotta be careful saying this or PETA will be on my
ass here :-)
He has a 52 now and has just bought an 11. I believe he's trying to
put a P&W in the 11 as we speak.
Got another friend in Jersey who's LOA on Mig 21's.
I think the Russians might be invading after all :-)

I'd say we might have some mutual acquantences.


Bertie

"muff528" wrote in
news:S1pbi.1718$O15.1221@trnddc03:


"Bertie the Bunyip" wrote in message
. 130...
"Maxwell" wrote in
:


"Bob Moore" wrote in message
46.128...
My name is Bob Moore :-)

Just what is a barrel roll has been debated between "Big John",
Dudley, and myself at least twice in the past. It IS difficult to
describe without having a model airplane in one's hand and flying
it through the maneuver.

How come you don't seem to belive the following from Wikipedia?

Barrel roll
From Wikipedia, the free encyclopedia

This article is about the aerial sport. For the military operation,
see Operation Barrel Roll.
A barrel roll occurs when an object (usually an airplane or roller
coaster)
makes a complete rotation on its longitudinal axis while following
a helical path, approximately maintaining its original direction.
The G load is kept positive (but not constant) on the aircraft
throughout the maneuver, commonly not more than 2-3 G.

In aviation, the maneuver includes a constant variation of attitude
in all three axes, and at the midpoint (top) of the roll, the
aircraft is flying inverted, with the nose pointing at a 90-degree
angle ("sideways") to the general path of flight. The term "barrel
roll" is frequently used, incorrectly, to refer to any roll by an
airplane (see aileron roll), or to a helical roll in which the nose
remains pointed generally along the flight
path. In fact, the barrel roll is a specific and difficult
maneuver; a combination of a roll and a loop. It is not used in
aerobatic competition.

From:
http://acro.harvard.edu

The Barrel Roll is a not competition maneuver. The barrel roll is
a combination between
a loop and a roll. You complete one loop while completing one roll
at the same time.
The flight path during a barrel roll has the shape of a horizontal
cork screw. Imagine a big
barrel, with the airplanes wheels rolling along the inside of the
barrel in
a cork screw path.
During a barrel roll, the pilot experiences always positive G's.
The maximum is about 2.5 to
3 G, the minimum about 0.5 G.


Then would you label the roll that Jim has described here as a form
of aileron roll, instead of a barrel roll? Or do you think it is
possible to do a 1g aileron roll?

It's less of a roll than it is a loop.


In fact, that's how I used to teach it. Get a hula hoop, cut it and
pull the ends apart. you are now looking at the path of a barrel
roll. A skewed loop


Bertie

Would it be possible to maintain 1g in the seat if the "corkscrew"
were modified to a shape like an opening spiral, similar to a nautilus
shell? Maybe slip to the right while pulling the nose up to induce
acceleration of 1g.

No.

Bertie

On 2007-06-12 00:14:09 -0400, Bertie the Bunyip said:

Dudley Henriques wrote in
news:2007061200011427544-dhenriques@rcncom:

On 2007-06-11 23:50:07 -0400, Bertie the Bunyip
said:

Dudley Henriques wrote in
news:200706112344078930-dhenriques@rcncom:

On 2007-06-11 23:27:09 -0400, Bertie the Bunyip
said:

Dudley Henriques wrote;

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.

That's what got Rollie Cole. Shame.
I miss the old days. I knew a lot of these people up close and
personal.Counting the people we knew on the jet teams and the rest
from the demonstration community, my wife and I have lost 32 friends
through the years to low altitude acro
Dudley

Yes. i've lost a few as well. Somehow I managed to survie it though!

I don't even like doing them at altitude so much these days. Except
for smooth stuff. A freind of mine has just got a Yak 52 and is going
nuts in it doing flat spins and what have you.. Gives me a headache
just looking at him!

That's weird. I have a friend in Pa. in the financial business who's
into Yaks as well. (Gotta be careful saying this or PETA will be on my
ass here :-)
He has a 52 now and has just bought an 11. I believe he's trying to
put a P&W in the 11 as we speak.
Got another friend in Jersey who's LOA on Mig 21's.
I think the Russians might be invading after all :-)

I'd say we might have some mutual acquantences.


Bertie

Wouldn't surprise me a bit, but fear not if so. Should the Bunyip
become known, his secret is safe and shall remain so.
For your interest, the two people are Seligman and Sutton.
Dudley Henriques

Dudley Henriques wrote in
news:2007061201080016807-dhenriques@rcncom:

On 2007-06-12 00:14:09 -0400, Bertie the Bunyip
said:

Dudley Henriques wrote in
news:2007061200011427544-dhenriques@rcncom:

On 2007-06-11 23:50:07 -0400, Bertie the Bunyip
said:

Dudley Henriques wrote in
news:200706112344078930-dhenriques@rcncom:

On 2007-06-11 23:27:09 -0400, Bertie the Bunyip
said:

Dudley Henriques wrote;

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.

That's what got Rollie Cole. Shame.
I miss the old days. I knew a lot of these people up close and
personal.Counting the people we knew on the jet teams and the rest
from the demonstration community, my wife and I have lost 32
friends through the years to low altitude acro
Dudley

Yes. i've lost a few as well. Somehow I managed to survie it
though!

I don't even like doing them at altitude so much these days. Except
for smooth stuff. A freind of mine has just got a Yak 52 and is
going nuts in it doing flat spins and what have you.. Gives me a
headache just looking at him!

That's weird. I have a friend in Pa. in the financial business who's
into Yaks as well. (Gotta be careful saying this or PETA will be on
my ass here :-)
He has a 52 now and has just bought an 11. I believe he's trying to
put a P&W in the 11 as we speak.
Got another friend in Jersey who's LOA on Mig 21's.
I think the Russians might be invading after all :-)

I'd say we might have some mutual acquantences.


Bertie

Wouldn't surprise me a bit, but fear not if so. Should the Bunyip
become known, his secret is safe and shall remain so.
For your interest, the two people are Seligman and Sutton.

No, don't know them myself, but I think one had A CJ 6 ferried from Cal
a few years ago?

Also, i reckon you also knew a Pinto/ F86 driver that bit off more than
he could chew?




Bertie