Myth: 1 G barrel rolls are impossible.

writes:

'Some combination', 'several possibilities.' I'm confused by this -
can you be more precise? What are the possibilities?

You can move and accelerate in any combination of three dimensions, with any
combination of acceleration rates, almost. You have to calculate the
direction and magnitude of the net acceleration vector to determine exactly
how much force is acting upon the pilot, and in which direction.

Some of it is (or should be) intuitive. For example, if you turn the aircraft
to the right, you'll be accelerated to the right.

Why?

mike

"Mxsmanic" wrote in message
...

If it is equal to 1.0 G (which would be quite a feat),

mike regish writes:

Why?

It's hard to maintain a downward acceleration of 1 G in any aircraft,
especially a small, non-aerobatic aircraft.

Mxsmanic wrote in
:

mike regish writes:

Why?

It's hard to maintain a downward acceleration of 1 G in any aircraft,
especially a small, non-aerobatic aircraft.

How would you know, fjukkwit, you don't fly.


Bertie

Didn't say anything about maintaining it. It is easy to attain zero g in an
airplane. And if you start out with a steep climb, you can sustain zero g
for several seconds easily. I know because I do it all the time. My kids
love watching their soda bottles floating up in front of them.

mike

"Mxsmanic" wrote in message
...
mike regish writes:

Why?

It's hard to maintain a downward acceleration of 1 G in any aircraft,
especially a small, non-aerobatic aircraft.

On Jun 14, 9:39 pm, "mike regish" wrote:
Didn't say anything about maintaining it. It is easy to attain zero g in an
airplane. And if you start out with a steep climb, you can sustain zero g
for several seconds easily. I know because I do it all the time. My kids
love watching their soda bottles floating up in front of them.

I used to move an item from one side of the cockpit to the other and
back and forward just to impress the pax..
Then on the ground I'd drop the item just to show pax the speed we
were descending at at the time ...

Mxsmanic wrote in
:

writes:

Got it. What happens to the g force acting on me as a pilot if I
start in straight and level, unaccelerated flight, and then I use
down elevator and enter a descent?

As you descend, you are accelerated downward. This acceleration is
subtracted from the constant acceleration imposed by gravity. If your
acceleration downward is less than 1.0 G, you experience a diminished
G force, unchanged in direction. If it is equal to 1.0 G (which would
be quite a feat), you will experience no G force at all. If it is
greater than 1.0 G (unlikely indeed), you'll feel a negative G force
tending to lift you out of your seat. These changes persist only for
as long as you are accelerating downward; once you are descending at a
steady rate, you will again experience exactly 1.0 G.

The latter circumstances are unlikely because accelerating downward at
1.0 G would give you a descent of 1920 fpm after one second, 3840 fpm
after two seconds, and so on.

Nope, you're an idiot.


Bertie

In article ,
says...
writes:

Got it. What happens to the g force acting on me as a pilot if I start
in straight and level, unaccelerated flight, and then I use down
elevator and enter a descent?

As you descend, you are accelerated downward.

No you are not - not relative to "self" (not the earth). Yer a moron.

Relative to yourself - in the plane - you can do a 1G roll (not a very
tidy one, and not one you'll see in the books). The 'book' describes
(as has been written here already), typically a descent to build
airspeed, then a climb and bank, then into it and over and recover
level.

To put it another way, if you closed your eyes, you wouldn't know you've
done a roll (given you go for the 'non-standard' 1G roll), other than
the initial sensation of beginning the turn, and then the sensation of
the turn stopping.

--
Duncan

Dave Doe wrote:

To put it another way, if you closed your eyes, you wouldn't know you've
done a roll (given you go for the 'non-standard' 1G roll), other than
the initial sensation of beginning the turn, and then the sensation of
the turn stopping.


Not sure exactly where you are with this, but as what you are saying
pertains to barrel rolls begun from level flight or from a position with
the nose below the horizon, don't forget that the entire gist of the
misunderstanding that has been running rampant on this thread about
barrel rolls and doing them at 1 positive g can be centered and
completely focused on the fact that it's the ENTRY and the EXIT of the
roll, and how these two factors interplay into the roll itself that is
causing all the confusion.
The one factor that can't be taken out of the barrel roll scenario is
that no matter how you cut it, if PITCH is a factor in a barrel roll,
there will be an indication on a g meter above 1 g as that pitch change
is being made. In a normal barrel roll you have pitch change as the nose
transverses the roll in it's helical path.
If a barrel roll requires the nose of the aircraft to be above the
horizon during the entry and then again brought back to the horizon
during the recovery (as it does) you will absolutely be showing more
than 1 positive g on the g meter during the roll, and if it's a
retaining double needle g meter, after the roll when you bring the
airplane home........period! This is a fact of life. As soon as the
aircraft's nose shows a positive nose rate in PITCH as it's raised
during the roll entry and then again during the recovery as it's raised
again to level flight, that g meter will leave 1 and show more than 1
positive g.

Now here is the part that is causing all the confusion. ONCE the nose
has been raised above the horizon (and that over 1 g has been registered
on the g meter) as you feed in aileron you can PLAY WITH THE BACK
PRESSURE being applied and EASE OFF the positive g to a LOWER LEVEL if
desired over the top of the roll, but that level can't be unloaded below
1 g or the arc of the roll will be destroyed. It's the COMBINATION of
roll and pitch that is producing the roll arc and those TWO pressures
MUST be maintained to produce the roll.
So the bottom line is simply that to do a barrel roll where the nose
must be both above and below the horizon line starting from level flight
you need over 1 g during the entry and exit, but you can reduce the g to
1 through the top of the roll if desired.

Dudley Henriques

I don't know how anyone can make it more clear than that. If you don't
believe this, you have never done barrel rolls and should do so, with
appropriate plane and instructor, before saying any more.

Dudley Henriques wrote:


Not sure exactly where you are with this, but as what you are saying
pertains to barrel rolls begun from level flight or from a position with
the nose below the horizon, don't forget that the entire gist of the
misunderstanding that has been running rampant on this thread about
barrel rolls and doing them at 1 positive g can be centered and
completely focused on the fact that it's the ENTRY and the EXIT of the
roll, and how these two factors interplay into the roll itself that is
causing all the confusion.
The one factor that can't be taken out of the barrel roll scenario is
that no matter how you cut it, if PITCH is a factor in a barrel roll,
there will be an indication on a g meter above 1 g as that pitch change
is being made. In a normal barrel roll you have pitch change as the nose
transverses the roll in it's helical path.
If a barrel roll requires the nose of the aircraft to be above the
horizon during the entry and then again brought back to the horizon
during the recovery (as it does) you will absolutely be showing more
than 1 positive g on the g meter during the roll, and if it's a
retaining double needle g meter, after the roll when you bring the
airplane home........period! This is a fact of life. As soon as the
aircraft's nose shows a positive nose rate in PITCH as it's raised
during the roll entry and then again during the recovery as it's raised
again to level flight, that g meter will leave 1 and show more than 1
positive g.

Now here is the part that is causing all the confusion. ONCE the nose
has been raised above the horizon (and that over 1 g has been registered
on the g meter) as you feed in aileron you can PLAY WITH THE BACK
PRESSURE being applied and EASE OFF the positive g to a LOWER LEVEL if
desired over the top of the roll, but that level can't be unloaded below
1 g or the arc of the roll will be destroyed. It's the COMBINATION of
roll and pitch that is producing the roll arc and those TWO pressures
MUST be maintained to produce the roll.
So the bottom line is simply that to do a barrel roll where the nose
must be both above and below the horizon line starting from level flight
you need over 1 g during the entry and exit, but you can reduce the g to
1 through the top of the roll if desired.

Dudley Henriques