an exercise for sim pilots -- a 1 G roll

The physics of this 1 g roll are nicely demonstrated at

http://www.stanford.edu/~siegman/one_g_roll.html


The question I had asked in the first posting seems to have been
answered by Kyle.


This was almost as much fun as the airplane on a treadmill thread --
thanks everyone.


Now there's an idea. Let's design a treadmill that follows the 1 g roll
path and sell it to Disney! It wouldn't be much fun for the kids riding
it, would it? ( I have one year from first public disclosure to file a
patent application, right?)

On Jan 5, 9:05 am, "Tony" wrote:
On Jan 5, 6:51 am, Mxsmanic wrote:

Tony writes:
In fact you are wrong. You may wish to look in the archives of this
newsgroup for the proof.The archives of this newsgroup are proof of nothing.Ah, but if you are capable of the task, you can apply some classical
physics to the information provided in the archive and do the analysis
yourself.

If you are not capable of the analytical physics you might have to do
experimental physics. In your case if you have the skills those can be
gamed.

Or, remain ignorant, and wrong.

Again.





You cannot change altitude without acceleration, and that changes G
force. You cannot execute any type of roll that involves any change
in altitude without a change in G force. This is basic physics.

If you roll the aircraft without a change in altitude, the magnitude
of the G force can be held constant. However, in that case, you
cannot keep the vector pointed in the same direction.

If you want positive G through the normal vector when moving through
the inverted portion of a roll, you _must_ accelerate downward at at
least one G at some point, otherwise gravity will reduce G to zero and
make it negative. When the aircraft is inverted, gravity produces
-1.0 G of acceleration on the pilot. The only way to counter this is
to accelerate downward at at least 1 G.

I do think you didn't quite say what you meant when you stated you
cannot change altitude without changing G. What g force would you
expect it you were climbing at 500 feet a minute?None, but you would experience greater than 1 G as you started the
climb, and less than 1 G as you ended it. You have to accelerate
upward to start a climb and downward to stop it. You cannot
accelerate without inducing G forces. The same is true in turns.

--
Transpose mxsmanic and gmail to reach me by e-mail.- Hide quoted text -- Show quoted text -

Tony writes:

Ah, but if you are capable of the task, you can apply some classical
physics to the information provided in the archive and do the analysis
yourself.

Acceleration is a change in velocity. Climbing from the ground (or
from any constant altitude) is a change in vertical velocity (since
the initial rate of climb is zero). Therefore climbing involves
acceleration. G forces are nothing more than acceleration. Therefore
climbing changes G forces. QED.

If you are not capable of the analytical physics you might have to do
experimental physics.

Nothing that complicated is required. See above.

--
Transpose mxsmanic and gmail to reach me by e-mail.

"Mxsmanic" wrote in message
...
Tony writes:

Ah, but if you are capable of the task, you can apply some classical
physics to the information provided in the archive and do the analysis
yourself.

Acceleration is a change in velocity. Climbing from the ground (or
from any constant altitude) is a change in vertical velocity (since
the initial rate of climb is zero). Therefore climbing involves
acceleration. G forces are nothing more than acceleration. Therefore
climbing changes G forces. QED.

You are correct, but for typical climbing and decending the amount of G away
from 1 is so small that as a pilot it is still "1". Entering a climb or a
decent moves a G meter such a small amount, you can't see the needle move
and you can't feel the small difference in the seat of your pants. There
are small G changes in a barrel roll, but not enough to really feel. As a
pilot, the manuever is called "1 G". Keep in mind this is in comparison
with other aerobatic manuevers that go to routinely 3 to 10 Gs.

Danny Deger