Path of an airplane in a 1G roll

On Sun, 19 Jun 2005 11:04:39 -0500, Chris W wrote:

4 Groups?

Do we have any who is a math whiz here? I want to find a formula to
calculate the position of an airplane throughout a 1G roll. The reason

At any rate, do you want to maintain 1G, or just positive G? it's a
big difference.

You can do a barrel roll and maintain positive G all the way around.
It's a very simple maneuver and very easy to do. It's also probably
one of the easiest to screw up.

I'm doing this is so I can build a "roll track" for a remote control car

Remember that in straight and level flight you are pulling 1G. If you
start a roll you will have to start adding nose up stick to maintain
1G to the point of 1G when inverted. "
"Theoretically" as you rolled past inverted you would start reducing
back pressure until you were back wings level.

At this point it takes some one much more versed in aeronautic theory
(and practice) than I, but... A barrel roll comes the closest to what
you are asking. It, however starts out at more than 1G. Typically 2Gs
and it can be more. With a 2G pull up at the start, you will be
pulling 1G when passing inverted.

Remember you started out in a nose high attitude to get to this point.
So in the theoretically description you would most likely be way nose
low at the 180 degree inverted position and I think you will probably
get well past 2 Gs getting back to the wings level position.

so the car will alway have a positive g force on it to keep it on the

But, if it's just the positive Gs you need, shape the track like the
path a plane would take through a barrel roll. It would go up and
curve to the right forming a corkscrew shape with the end right back
at the same level as the beginning. You can add turns as well "as
long as the car is changing direction in relation to *its" own
vertical axis. For example if the car is on its right side the track
needs to be curving right, if on its left then the track needs to be
curving left. If the car is inverted the track needs to be curving
down.

Remember too that the car has to be going fast enough to maintain the
desired G forces and traction. Slow down and it'll just fall off.

Roger Halstead (K8RI & ARRL life member)
(N833R, S# CD-2 Worlds oldest Debonair)
www.rogerhalstead.com
track. Anyone have any ideas? So far my attempts have have all come up
short. They don't pass what my college calculus instructor called the
"warm and fuzzy" test. I think it has been too long since I took those
classes.

My take on this is that an airplane in a 1G roll would follow the same
path as any other object.

Imagine your in space. A 1G roll would be a perfect circle with a
constant 1G acceleration.

Now bring that path into the Earth's gravity well. Now the 1G roll is
all messed up by the Earth's 1G. How can we fix that? Just like the
Vomit Comet does, by accelerating down at 9.8m/s^2. Superimpose a roll
on top of a parabolic descent and you have the path of a theoretical
airplane in a 1G roll.

I don't think there is a plane that could actually perform this maneuver
in reality.

--
This is by far the hardest lesson about freedom. It goes against
instinct, and morality, to just sit back and watch people make
mistakes. We want to help them, which means control them and their
decisions, but in doing so we actually hurt them (and ourselves)."

On Wed, 29 Jun 2005 04:01:56 +0100, Ernest Christley
wrote:

My take on this is that an airplane in a 1G roll would follow the same
path as any other object.

Imagine your in space. A 1G roll would be a perfect circle with a
constant 1G acceleration.

Now bring that path into the Earth's gravity well. Now the 1G roll is
all messed up by the Earth's 1G. How can we fix that? Just like the
Vomit Comet does, by accelerating down at 9.8m/s^2. Superimpose a roll
on top of a parabolic descent and you have the path of a theoretical
airplane in a 1G roll.

I don't think there is a plane that could actually perform this maneuver
in reality.

Obviously, the quicker you can roll, the easier it would be, but
essentially it would be impossible to complete a constant 1G roll back to
S&L. You would have to end up in a nose-down attitude in order to
maintain 1G while inverted. The greater your roll rate, the less time
you'll need to maintain positive G while inverted, and hence the nose
won't need to drop as far. The closest you're going to get to this is a
simple aileron roll where you start nose high... but then you've pulled
more than 1G to get the nose in to that position!



--

PERCUSSIVE MAINTENANCE:
The fine art of whacking the cr*p out of an electronic device to get it to
work again.