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XyZspineZyX
12-15-2003, 03:05 AM
Have been trying out a force feedback stick. Does it really take this much force in a real plane to induce roll movements (left and right) versus pitch (forward and backward)?

Thanks

http://www-rcf.usc.edu/~nagle/p51dalone.jpg


Atticus

XyZspineZyX
12-15-2003, 03:05 AM
Have been trying out a force feedback stick. Does it really take this much force in a real plane to induce roll movements (left and right) versus pitch (forward and backward)?

Thanks

http://www-rcf.usc.edu/~nagle/p51dalone.jpg


Atticus

XyZspineZyX
12-15-2003, 03:09 AM
I did just find this old post. There is some points in reference to greater than 50 lbs of stick force to roll so.


Hi, First, I want to say that I like IL2 demo for its atmosphere and
details..and I just like it.

However, in flying the IL2 P-39 Airacobra, I looked at some P-39 NACA tests
I have: Among them:

1) "NACA wartime report MR 1945 measurements of the flying quliities of a
Bell P-39D-1"

2) "NACA report ACR Oct 1940" and saw some interesting things.

One was a steady state roll rate chart for 360 degrees roll for the P-39D-1.
At speeds above 235 MPH, the pilot was exerting 50 LBS of stick force.
Below that speed, he was exerting full aileron deflection.

Note two things:

1) That the fastest NACA P-39 roll was 4.8 seconds at 235 mph (IL2's P-39
is 1.8 seconds for me).

2) That the roll rates are in a bell shaped curve that is reached when the
pilot simply runs out of strength. That speed is 235 MPH in this P-39D-1
NACA test.

Here are the NACA results:

160 mph- 6.67 sec.

200 mph- 5.8 sec.

235 mph (best roll rate speed)- 4.8 sec.

250 mph -5.0 sec.

390 mph -7.3 sec. (Hmmmm, in IL2 I can roll the P-39 in 1.8 sec at this
speed!!!!)

However,... "It's (P-39's) time constant to start rolling was extremely
fast..."...so it could start a roll very quickly (ie. sensitive to control
inputs)..but then just took a long time to get there...a lot like the P-51D
Mustang in roll handling this way (As I have personally found and a British
flight test state [AFDU /3/21/36 8th March, 1944).

This is not to sit here and cream the IL2 demo...it is a good sim...however
this and my own Mustang and Spitfire aerobatic experience points out (with
similar results done with a stop watch) that perhaps in IL2 demo:

1) Roll rates should be slower for the fighters (except the FW 190 if
implemented-a NACA test I have gives it a rare 2.2 sec max roll rate at 260
mph). (The NACA P-51 B was doing 4.2 second rolls at this speed in the same
test...ouch!)

2) Roll rates should slow down at the higher speed levels as pilots run out
of muscle to overcome the force of the increasing air flow over the control
surfaces as all my roll charts show except for the boosted controls P-38).

A BF 109E (with clipped wings compared to the later "G" model ) flight test
shows an initial time to 45 degrees of 4 seconds alone at 400 mph. The BF
109G in pitch was almost unmoveable at 400 MPH according to the late Mark
Hanna as well with personal correspondance. In IL2, I can definitely
maneuver the BF 109 up and down at 400 mph by comparison.

The RAE BF 109E test 2361 states that "at 400 MPH a pilot exerting all his
strength, can only apply 1/5 aileron." However, it also admits that the
Spitfire Mk. I with the fabric covered ailerons also had the same slow roll
rate (later improved in the Mk5 by adding metal ailerons so that the aileron
fabric did not balloon at high speeds). However, then the ultra thin
Spitfire wings twisted/warped at high speeds still keeping the roll rate
sluggish at speeds approaching 400 MPH (according to the AFDU test).

"'the aiulerons and elevator of the Me.109 became so heavy in the dive that
rapid manoeuvring was impossible..." (2361)

This means that in IL2 for tactics that the BF 109 which was notorious for
being unmoveable at high speeds now has a massive advantage in IL2 by being
able to unhistorically not have to worry about high speeds at the advanced
flight model level.

Now, these NACA tests also state some P-39 handling issues which IL2 seems
to have been well-done on the most challenging level flight model:

"P-39 D fore-aft stick movement of one inch would change wing lift
coeffieient from a high speed value of .20 to a near stall 1.40 with normal
center of gravity (CG)."

"Light stick forces-normal CG fore-aft stick force per g in a turn was less
than two pounds".

In other words the p-39 is a rather sensitive aircraft in pitch and roll
axes.

Another thing which IL2 (and many other sims might want to work on is the
ability to constantly turn while using rudder...ie used for slipping evasive
maneuvers. I find that the IL2 planes really don't keep slipping (turning)
with rudder input after the initial input (look at the non-turning outside
clouds and non- turning compass). Most airplanes with a rudder will do
this...especially marginally stable fighter aircraft. I definitely performed
continual sideslips on the Spitfire and Mustang and have the evidence taped
from the cockpit in the Mustang for proof (when I was doing yaw stability
tests).

Again, I think that IL2 demo shows a great sim and that it is enjoyable, and
I like it.

Richard Ordway


http://www-rcf.usc.edu/~nagle/p51dalone.jpg


Atticus

XyZspineZyX
12-15-2003, 03:16 AM
Just came across this as well.

"In WWII, most aircraft rolled at very different rates depending on how
fast they were going. At middle speeds, like around 250 mph, most
aircraft realised their optimal roll speed. At higher speeds the
ailerons became increasingly hard to operate and roll rate became a
matter of how strong the pilot was. In the Spitfire, it was often the
case that high speed maneuvering required two hands to force the stick
over."

This is making me realize that the AI are not showing any limitations to roll power. They are rolling all over the place at very high speeds. They have a 500lb super AI with big arm muscles who is yanking that thing all over the place.





http://www-rcf.usc.edu/~nagle/p51dalone.jpg


Atticus