an exercise for sim pilots -- a 1 G roll

T o d d P a t t i s t writes:

I do wish people would stop discussing the roll. A pure
rolling motion cannot affect the force vector in any way
relevant to producing 1 G into the seat.

It's certainly true that rolling alone does not change the magnitude
of the acceleration vector at axis around which the roll occurs.

Mx is right, but I think he misses the point - there's
nothing that says we can't start in a steady climb or end in
a steady descent. Both have a steady 1G load on the
aircraft.

Even if you start in a steady climb or descent, you cannot avoid a
change in G forces in any maneuver that requires a change in the rate
of change of altitude, which includes a typical barrel roll that
preserves positive G on the pilot.

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

Steve Foley writes:

I believe you could decrease your altitude while banking and maintain 1G
from level flight.

No matter what you do, at some point you will deviate from 1 G.

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

Jose writes:

Tilting the 1G vector back, the nose comes up.

Remember: Whenever the vector is not normal to the surface of the
planet, its magnitude will vary from 1 G, because it must always
contain a 1 G component that is normal to the surface.

This is why you cannot enter a 90-degree bank in a coordinated turn,
for example.

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

Tony writes:

... I can show you how to go from straight and level into a climb
maintaining one g into the seat ...

Show me.

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

Tony writes:

I made a mistatement in my prior post. I do not know how to get into a
30 degree climb from straight and level without experiencing a change
in preceived G forces.

Ah, I am reassured.

In fact, any change in climb rate requires a change in G. So unless
your aerobatic maneuver can be executed without any change in your
climb rate at any point, it will involve a change in G.

--
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

Danny, you are correct when you say the actual deviation from 1 G is
small for climbs, but small isn't good enough. I wanted what we trained
in the sciences would call 1, an integer, not 1.00. The problem I could
not resolve in entering a climb is not getting the airplane to pitch up
30 degrees and maintaining 1 g into the seat -- it just has to
decelerate to do that. I just don't seem to have the degrees of freedom
that are needed.

Some - Mx is an example -- don't quite understand how to do the
analysis, and would rather argue than show where the math I cited is in
error. Too bad, it could have been a learning experience for them.

Do take a look at the neat family of curves in the citation: it's
interesting stuff, and guess what? If the equations of motion are
solved in closed form, G is 1, into the seat.



On Jan 5, 5:53 pm, "Danny Deger" wrote:
"Mxsmanic" wrote in messagenews:bfftp2t07l335t5qr0s08dsdb80vjr1bnt@4ax .com...

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

In article ,
says...
Duncan writes:

Are you a troll?

No.

Why don't you head down to your local flight school and do a $100 trial
flight?

In part because $100 is almost what I make in a week. In part because
there are no local schools. In part because I have no time or
transportation to get to a flight school. And in part because, even
if I enjoyed the flight, I have no resources to pursue any type of
real-world flying.

So? Nothing ventured nothing gained.

You'll get a logbook and get to make your first entry in it.

Wow. Do I get small appliances after logging a certain number of
hours?

???


You'll get to fly a real plane, hands on.

Wow.

Actually, I'd much rather have time on some full-motion sims.

How do you know? Flown a plane already? If not, you have no evidence to
make such a comparison.

--
Duncan

Duncan writes:

???

I simply meant that I see no advantage to logging hours.

How do you know? Flown a plane already? If not, you have no evidence to
make such a comparison.

I'm already certain. A full-motion sim would be more fun than a
non-motion sim, in most cases, and it would have none of the drawbacks
of flying a real aircraft.

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

Tony writes:

Some - Mx is an example -- don't quite understand how to do the
analysis, and would rather argue than show where the math I cited is in
error. Too bad, it could have been a learning experience for them.

I've explained the error. You cannot change your rate of climb
without accelerating. You cannot accelerate without deviating from 1
G. You cannot maintain a constant rate of climb forever, so you must
change the rate of climb from time to time. And any maneuver that
changes the rate of climb (which, in practice, is roughly the same as
saying any maneuver that changes altitude) will change the G forces.
It's very simple, and doesn't require any fancy physics.

Do take a look at the neat family of curves in the citation: it's
interesting stuff, and guess what? If the equations of motion are
solved in closed form, G is 1, into the seat.

You can solve all the equations you want, but you cannot escape from
the reality I've described above.

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