HTC, a question about roll rate modeling?

[Karnak]

I was thinking about the NACA chart that showed the roll rate of various aircraft and various speeds with 50lbs of stick force.  The chart that was used to illustrate the Typhoon's excessive roll rate.

How much force can be applied to the stick to roll the aircraft? 50lbs?  75lbs?  I have no idea.  How much is being assumed in AH?

If AH is assuming 50lbs is the max, then the Typhoon is now about right, the A6M5b is too fast, the Spitfire is too fast at higher speeds and the Fw190 is too slow.  If more than 50lbs of force can be applied, then it is likely that only the Typhoon is to slow and the Fw190 is too slow.  The other aircraft in AH could very well be accurate representaions of the stick force being used in AH if the force is greater than that of the NACA test.

Furthermore, there is the issue of how much deflection is obtained.  It is entirely possible to get the same exact roll rate out of 50lbs of stick force as one gets out of 100lbs of stick force simply becase 50lbs is enough, on that aircraft at that speed, to fully deflect the aerilons.

I am wondering if the NACA chart is fully applicable to AH.

[ 07-15-2001: Message edited by: Karnak ]

[Zigrat]

karnak,
its pretty easy to see where the aerodynamic limits end and the stick force limits begin.. the roll rate will be increasing until teh stick force limit is reached then start decreasing

imo the thing that htc doesnt model is aileron reversal, which was a big problem in the normal wing spitfires. I'd like to see the normal spitfire wing roll rate fixed, and have a lf.ix clip wing added, which would be a hotrod of a non perked fighter for RAF fans (i like the lf.ix clip too   )

just so im not looking luftwobblish i think the roll rate of the 109 might be too high at extreme speeds too...

[R4M]

Originally posted by Zigrat:

just so im not looking luftwobblish i think the roll rate of the 109 might be too high at extreme speeds too...

the 109 has rollrate at extreme speeds?

now THAT is something new    

[Hristo]

So, if I remember correctly, all planes roll too fast while 190 rolls too slow ?

[DB603]

S!

 109G-2 roll rate was not bad.At speeds of 300km/h and above it rolled in about 4 seconds without using rudder to help.Even with gondolas the roll rate was the same.They didn't affect the roll rate,but the start of the roll(minimal).Roll was said to be easy and tendency to drop nose was slight.This countered by starting the roll with 10 deg nose up.Tests were made 1943 with Bf109G-2,Finnish Air Force.

[Karnak]

Hristo,

No, the Spitfire rolls too slowly at low speed and too fast at high speed when 50lbs of stick force are applied.

The 190 simply rolls too slowly.

But all of that is beside my point.

My point was that the test was with 50lbs of stick force.  If more stick force is being modeled in AH then the roll rates would be higher, up to the limits of the airframe.

Zigrat,

Yes, it would be good to see the aerilon reversal that occurred in the Spitfire wings modeled.

I want to make it clear that I'm not trying to get one airframe a benefit here.  It is simply that I want all airframes modeled on the same terms.

It seems to me that the Typhoon is now modeled with 50lbs of stick force whereas everything else may be at a higher stick force.

The Fw190 simply rolls too slowly, and that I would like to see fixed as well.

[ 07-15-2001: Message edited by: Karnak ]

[straffo]

What about a pilot modelling ? (like in the competition  )
I thing that the average "virtual" pilot can pull more than 50 lbs at 1st move ,50 for 2nd move under 50 at 3rd etc...

And when exausted he would be dead meat  

[Seeker]

Since when could any one *ever* apply 50lbs lateral pressure on a 109 stick?

You may be openeing up a can of worms you'd wish left untouched....

This may be of germaine interest:
 http://www.geocities.com/spades53.geo/prodocs.htm

[Karnak]

straffo,

You are, I take it, refering to WW2Online.  I don't really see that as competition.  It is so laggy as to make dog fighs impossible.

Additionally, even in a multi-minute turn fight in the Spitfire MkIa, I never had the fatigue level come into play, let alone on the 2nd turn or roll.

I truely have no idea ho much stick force your average pilot could apply for turns and rolls in any given airframe.  I have no idea what the fatigue rate for an average WWII fighter pilot was either.  Saburo Sakai certainly described it, but that was post wound and in a long fight against desparate odds, and even then it didn't stop him.

Seeker,

Nice!

[ 07-16-2001: Message edited by: Karnak ]

[MiG Eater]

To get to the real nitty gritty, then the stick length would have to be appropriately modeled as well.  A 50 lb force on the end of a short control stick has less mechanical advantage than a 50 lb force on a long control stick.

MiG

[F4UDOA]

Gents,

In a modern evauluation done in 1989 by a group of military test pilots known as the "Society of expermental Test pilots" did a report to determine the best of the American WW2 fighters.

Borrowing A/C from different collectors the ballasted the A/C for various weights and checked engines for rated HP and then conducted several test.

One of which was roll rate and another was pound per G of stick force.

Roll time 360 degrees and rate 200KIAS 10,000ft.

P-47D-40
Right 4.9sec(74deg per sec)
Left 5.9sec (61deg)

FG-1D (F4U-1D)
Right 4.5sec 81deg
left 4.9sec 73deg

F6F-5
Right 4.6sec 78deg
Left 5.9 61 deg

P-51D
Right 4.8 75 deg
Left 5.1 71 deg

Pounds per G of stick force

FG-1D 5lbs per G
P-47D-40 7.5lbs per G
F6F-5 12.5lbs per G
P-51D 20lbs per G

Hope this adds some insight

[dtango]

I'm a little lost here.  Can someone point to me to the NACA report so that I can try and figure out what 50 lbs of stick force is and how they did that test?  Or if someone wants to educate me on what lbs of force on the stick relate to I would appreciate it   !

Not sure what to make of the 50lbs of force vs. the lbs of force per G listed by F4UDOA and how they are related.

Thanks!

[Naudet]

50 lbs stock force would mean u haveto pull with the power of 50lbs left or right on the stick to get the am  special roll rate.

Its the power u must apply so ur control surfaces move into the air stream and sta there.

The higher the stick force the more power u must use to moe the stick.
when the force is to great to be applied by u, u cant move ur plane, i.e. at speeds above 350mph the ZERO ailerons locked due to the power of the air stream floating above em, increasing the stick force so much, no pilot could apply it.

late WW2 planes (P38L, FW190D13) had hydraulic boost systems than allowed lower stick forces at high speeds, by assisting the pilot.

hope that helps

[dtango]

Thanks for clearing it up Naudet.  I thought that's what it meant but wasn't sure.

So the question is still open:
(1) How does AH model this?

My other question is:
(2) What does F4UDOA's post mean?- the lbs/G stick force listed for the various aircraft listed?

[F4UDOA]

Dtango,

I'm not sure what your first question is asking but the data I posted is this

For instance a P-47D pulls into a 4G turn. How hard is it for the pilot to maintain that constant turn rate. According to the test results from the Tes Pilots who flew the various A/C the P-47D took 7.5 pounds to pull 1 G, so a 4 G turn is 7.5 * 4 = 30pounds of force. This may not seem like a lot of weight but in a sustained dogfight pulling even higher G's the pilot is likely to become very worn down from wrestling his A/C around. Remember the pilot is also sustaining the effects of G force and a 200pound pilot pulling 4 G's now weighs 800lbs, Very tiring. So a P-47 actually has very light controls relative to a P-51 which would require 20lbs per G or 80lbs of force in a 4 G turn. Not good!!

BTW, this effect is not modeled in AH or anywhere in the virtual world that I am aware of.