Myth: 1 G barrel rolls are impossible.

wrote in message
oups.com...
1. If I enter a coordinated turn, I experience an increase in Gs.
2. If I enter a descent, I experience a decrease in Gs.

If I do these two things at the same time, it is possible to enter a
descending turn without any change in Gs.

Yes. Note, however, that you must _accelerate_ downward, and not merely
drift
downward at a constant rate.

Right. A major part of your argument in this thread has been that it
is impossible to change the direction in which the plane is travelling
without accelerating the plane. Your own analysis, based on my
questions, clearly shows that it is possible to change the direction
the plane is going in without deviating from the 1G being exerted.
Note that the I am not denying that the aircraft is accelerating in
this situation. But it is doing so without a change in force being
felt. So where your argument breaks down is in the assumption that if
changing the direction requires acceleration, then acceleration will
require a change in G force.

I am not saying that this is, in of itself, proof of the possibility
of the 1G barrel roll. It does, however, clearly indicate a flaw in
your argument. I find it odd that you find it so hard to believe that
people can believe that changes in direction are possible without
accelerations being felt, given that by your own admission, these
people are actually correct.


Of course, all combinations are indeed possible. But this interesting
special case of the situation exists, doesn't it, in which there is no
change in the force felt by the pilot?

Yes. It sounds a lot like a spin.

What? It sounds very little like a spin - try entering a spin with no
change in G force!


A change in direction does not *require* acceleration..........a change in
direction *is* acceleration.
You "feel" the effects of acceleration, whether it is caused by gravity, a
change in velocity, or
change in direction. All of these factors come into play when doing any
maneuver giving a net
result that you interpret as gee's, whether you are in freefall or in a high
gee turn.

Dudley Henriques wrote:
Matt Whiting wrote:
Dudley Henriques wrote:

There is a special case where you can unload the airplane in roll to
increase the roll rate. It's done in fighters all the time in ACM.
You can experience it in your everyday light aerobatic airplane by
doing an aileron roll from a nose high roll set position, then as the
airplane goes past the first knife edge position, go forward on the
pole to unload the wings but not enough to go negative. Keeping the
aileron in hard while you do this increases the roll rate and as a
side effect flattens the roll in pitch at the same time making it
prettier :-)

Why does this work?

Matt

Several factors effect roll rate, roll acceleration and roll inertia.
Basically why this works is that unloading the airplane while rolling
(aileron roll basically, not a slow roll) minimizes much of the
effectiveness issues experienced by the ailerons especially at low
airspeeds and high load factors when the wings are generating a fair
amount of lift. Anytime you want to maximize the roll rate, unloading
will achieve this. The exact point where the rate is maximized by
unloading will vary from aircraft to aircraft but basically the rule
still applies.
Dudley Henriques

Thanks!

muff528 wrote:
wrote in message
oups.com...
1. If I enter a coordinated turn, I experience an increase in Gs.
2. If I enter a descent, I experience a decrease in Gs.
If I do these two things at the same time, it is possible to enter a
descending turn without any change in Gs.
Yes. Note, however, that you must _accelerate_ downward, and not merely
drift
downward at a constant rate.
Right. A major part of your argument in this thread has been that it
is impossible to change the direction in which the plane is travelling
without accelerating the plane. Your own analysis, based on my
questions, clearly shows that it is possible to change the direction
the plane is going in without deviating from the 1G being exerted.
Note that the I am not denying that the aircraft is accelerating in
this situation. But it is doing so without a change in force being
felt. So where your argument breaks down is in the assumption that if
changing the direction requires acceleration, then acceleration will
require a change in G force.

I am not saying that this is, in of itself, proof of the possibility
of the 1G barrel roll. It does, however, clearly indicate a flaw in
your argument. I find it odd that you find it so hard to believe that
people can believe that changes in direction are possible without
accelerations being felt, given that by your own admission, these
people are actually correct.

Of course, all combinations are indeed possible. But this interesting
special case of the situation exists, doesn't it, in which there is no
change in the force felt by the pilot?
Yes. It sounds a lot like a spin.
What? It sounds very little like a spin - try entering a spin with no
change in G force!


A change in direction does not *require* acceleration..........a change in
direction *is* acceleration.
You "feel" the effects of acceleration, whether it is caused by gravity, a
change in velocity, or
change in direction. All of these factors come into play when doing any
maneuver giving a net
result that you interpret as gee's, whether you are in freefall or in a high
gee turn.



What's a gee? Is that like a gee whiz? :-)

Dudley Henriques wrote:
Matt Whiting wrote:
wrote:
You're right about a barrel roll, of course, I like that you can
rotate the wings through 360 degrees and maintain 1 G.

You could also, I think, start the 'roll' with an upward velocity
component of 320 feet a second and end it level, but hardly at the
same altitude (you'd be 1600 feet higher).

An even more interesting question would be, is there an airplane that
can fly this flight path? I think it would take massive control
surfaces to be able to pull a G with the yoke.

I'm not an aerobatic pilot, but pulling 1G with the elevator isn't
hard on any airplane I've flown.

Matt

Actually Matt, all you need to do with most g meters is to "tweak" the
stick with an instant of positive pitch pressure and release it. You
will register over 1 g just doing that :-))
Dudley Henriques

Unfortunately, I've never had the pleasure of flying a g meter equipped
airplane!

Matt

"Matt Whiting" wrote in message
...
muff528 wrote:
wrote in message
oups.com...
1. If I enter a coordinated turn, I experience an increase in Gs.
2. If I enter a descent, I experience a decrease in Gs.
If I do these two things at the same time, it is possible to enter a
descending turn without any change in Gs.
Yes. Note, however, that you must _accelerate_ downward, and not
merely drift
downward at a constant rate.
Right. A major part of your argument in this thread has been that it
is impossible to change the direction in which the plane is travelling
without accelerating the plane. Your own analysis, based on my
questions, clearly shows that it is possible to change the direction
the plane is going in without deviating from the 1G being exerted.
Note that the I am not denying that the aircraft is accelerating in
this situation. But it is doing so without a change in force being
felt. So where your argument breaks down is in the assumption that if
changing the direction requires acceleration, then acceleration will
require a change in G force.

I am not saying that this is, in of itself, proof of the possibility
of the 1G barrel roll. It does, however, clearly indicate a flaw in
your argument. I find it odd that you find it so hard to believe that
people can believe that changes in direction are possible without
accelerations being felt, given that by your own admission, these
people are actually correct.

Of course, all combinations are indeed possible. But this interesting
special case of the situation exists, doesn't it, in which there is no
change in the force felt by the pilot?
Yes. It sounds a lot like a spin.
What? It sounds very little like a spin - try entering a spin with no
change in G force!


A change in direction does not *require* acceleration..........a change
in direction *is* acceleration.
You "feel" the effects of acceleration, whether it is caused by gravity,
a change in velocity, or
change in direction. All of these factors come into play when doing any
maneuver giving a net
result that you interpret as gee's, whether you are in freefall or in a
high gee turn.

What's a gee? Is that like a gee whiz? :-)

No... it's like geez whiz......you spread it on bread to get a geez sammich.

I can't believe I took the time to do this.

If you started at abaout 18000 miles an hour (you had better be pretty
high!) when you flew this path you'd end up level with the horizon.

I think this is out of the range of most general avaition airplanes.
The neat thing is, though, if you wanted to have a real aerobatic
flight experience on a simulator, this is the one to try. Just create
a craft with the ability to go that high, that fast, with thrusters
than could do this thing. Why, you could pour coffee into a cup and
claim to have the same effects in the simulation as a real pilot would
have in the craft.

wrote in message
ups.com...
I can't believe I took the time to do this.

If you started at abaout 18000 miles an hour (you had better be pretty
high!) when you flew this path you'd end up level with the horizon.


It's called orbital velocity

http://electronics.howstuffworks.com/satellite3.htm


I think this is out of the range of most general avaition airplanes.
The neat thing is, though, if you wanted to have a real aerobatic
flight experience on a simulator, this is the one to try. Just create
a craft with the ability to go that high, that fast, with thrusters
than could do this thing. Why, you could pour coffee into a cup and
claim to have the same effects in the simulation as a real pilot would
have in the craft.

Of course it is, and in this trivial case I just calculated how far
one must travel in the 10 seconds of the track to have the earth curve
away 1600 feet.

Increase the roll rate -- jets can roll really quickly -- and the
speed starts dropping to 3 or 4 mach.

On Jun 15, 9:12 am, "El Maximo" wrote:
wrote in message

ups.com...

I can't believe I took the time to do this.

If you started at abaout 18000 miles an hour (you had better be pretty
high!) when you flew this path you'd end up level with the horizon.

It's called orbital velocity

http://electronics.howstuffworks.com/satellite3.htm



I think this is out of the range of most general avaition airplanes.
The neat thing is, though, if you wanted to have a real aerobatic
flight experience on a simulator, this is the one to try. Just create
a craft with the ability to go that high, that fast, with thrusters
than could do this thing. Why, you could pour coffee into a cup and
claim to have the same effects in the simulation as a real pilot would
have in the craft.- Hide quoted text -

- Show quoted text -

Here's a very realizable one g roll for any airplane -- it just
depends on one's frame of reference. I'll choose the sun, and get a
slow 1 G barrel roll with an 8000 mile diameter in 24 hours. Depending
on the direction the airplane is tied down, it could be backwards.

On Jun 15, 9:20 am, wrote:
Of course it is, and in this trivial case I just calculated how far
one must travel in the 10 seconds of the track to have the earth curve
away 1600 feet.

Increase the roll rate -- jets can roll really quickly -- and the
speed starts dropping to 3 or 4 mach.

On Jun 15, 9:12 am, "El Maximo" wrote:



wrote in message

oups.com...

I can't believe I took the time to do this.

If you started at abaout 18000 miles an hour (you had better be pretty
high!) when you flew this path you'd end up level with the horizon.

It's called orbital velocity

http://electronics.howstuffworks.com/satellite3.htm

I think this is out of the range of most general avaition airplanes.
The neat thing is, though, if you wanted to have a real aerobatic
flight experience on a simulator, this is the one to try. Just create
a craft with the ability to go that high, that fast, with thrusters
than could do this thing. Why, you could pour coffee into a cup and
claim to have the same effects in the simulation as a real pilot would
have in the craft.- Hide quoted text -

- Show quoted text -- Hide quoted text -

- Show quoted text -

wrote in message
ps.com...
Here's a very realizable one g roll for any airplane -- it just
depends on one's frame of reference. I'll choose the sun, and get a
slow 1 G barrel roll with an 8000 mile diameter in 24 hours. Depending
on the direction the airplane is tied down, it could be backwards.

MX could even 'fly' that one g