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XyZspineZyX
08-30-2003, 12:36 AM
~S! All

Elevator Response/Pitch rate of the P-39

What follows is an explanation of why the Elevator response of the P-39 is off and should be addressed in future FM development, if any further development is to occur beyond this date. As a caveat I'm not speaking to speeds and other comparisons or complaints of other FM's. Pitch rate like roll rate, and other dynamics is an integral part of the P-39s design, as it is in any aircraft, My on line and off line time this past week indicate that the elevator response is so slow now, the issue should be brought out.

I¦ve only flown the 1.1b patch for one week now. Overall the FM development process improvement has carried forward with improvements to some birds, most notably the Fw 190s and some areas in others.

In the case of the P-39 some changes are noted in the area of speed/accel ( not commenting as to the accuracy) however the elevator response is very markedly degraded to the degree that the machine's pitch rate degrades quite rapidly with speed to almost losing elevator effectivenss at close to maximum dive speeds. The described elevator control degradation was true of some aircraft but was not a trait shared by the P-39 to my knowledge. One clue that peaked my curiosity and led me to examine this on the P-39 is the strange and extreme trim change that occurs now in transitioning the model into landing configuration. Not much pitch change occurs on gear deployment, basically similar to what I understand about the real aircraft , but flap deployment at normal pattern entry speeds now demand almost full forward stick movement to prevent the nose from skying up. Pitch up on flap deployment is a common trait of (generally) high wing aircraft, but low wing aircraft generally pitch down on flap deployment. The reason and driving force is the location of the Center of Lift in relation to the Center of Gravity location. The Center of Lift moves further behind the C of G on flap deployment. The pilot being concerned with landing and slowing the plane must counter with some nose up trim to not over speed his approach. Having said all of this the P-39 with its unique configuration with its mass in close proximity to the C of G and C of L should likely experience little trim change in transitioning to landing configuration. Now the rest........

I have searched for performance curves on the P-39¦s Pitch Rate to further support my point with hard data. However at this writing I've haven't some across those, and time is marching on. If any one has seen 'em I'd appreciate a copy or forward them with my sincere thanks.

The only definitive reference I can cite right now is from America's 100,000 by Francis Dean, which refer to pilot reports. Many regular contributors to this forum have this reference; it only contains the Basic curves for power, climb, roll, and endurance.

I'll start this bug report and continue to try to turf up the "P"'s on pitch rate.

I anticipate comment, please be nice/i/smilies/16x16_smiley-happy.gif , and also keep in mind that if comparisons are brought forth on turn rate as a point or counter point; pitch rate is not the same as rate of turn. Pitch rate along with roll and the planes configuration deal with placing the machine in a turning attitude, or any change in attitude for that matter. Turn (rate of) is more determined by speed, the radius, G load, wing loading, power loading, and other dynamics which influence the airframe at any given angle of attack.

I'll also offer that what I'm talking about will make the '39 much more prone to stall and spin if you bank and yank it, as you can do now with the 1.1b FM. As it is the machine is out of character and benign as regards pitch rate and stall behavior in the main.

Excerpt, A's 100k, page 201:

"An outstanding characteristic of the P-39 was extreme control sensitivity; A P-39D fore and aft stick movement of only one inch would change the wing lift coefficient from a high speed value of 0.20 to a near stall 1.40 with a normal airplane center of gravity location. One pilot put it this way "you move the stick on the P-39 one eighth of an inch and you could throw it into a spin before you knew what was happening." In addition stick forces were light. At normal center of gravity location fore and aft stick force per G was less than 2 pounds, where the normally allowed minimum was 3 pounds per G."

Lastly, how about adjusting the control input in the FB setup page? Since FB came out, for the P-39 my pitch settings have been 100 pct across the page with little dead zone and no filter.

All the Best:



BPO5_Jinx
C.O. Replacement Air Group
Birds of Prey. 16th GvIAP
http://www.birdsofprey16thgviap.com
http://www.soaridaho.com/Schreder/RS-15/N50GL.html

XyZspineZyX
08-30-2003, 12:36 AM
~S! All

Elevator Response/Pitch rate of the P-39

What follows is an explanation of why the Elevator response of the P-39 is off and should be addressed in future FM development, if any further development is to occur beyond this date. As a caveat I'm not speaking to speeds and other comparisons or complaints of other FM's. Pitch rate like roll rate, and other dynamics is an integral part of the P-39s design, as it is in any aircraft, My on line and off line time this past week indicate that the elevator response is so slow now, the issue should be brought out.

I¦ve only flown the 1.1b patch for one week now. Overall the FM development process improvement has carried forward with improvements to some birds, most notably the Fw 190s and some areas in others.

In the case of the P-39 some changes are noted in the area of speed/accel ( not commenting as to the accuracy) however the elevator response is very markedly degraded to the degree that the machine's pitch rate degrades quite rapidly with speed to almost losing elevator effectivenss at close to maximum dive speeds. The described elevator control degradation was true of some aircraft but was not a trait shared by the P-39 to my knowledge. One clue that peaked my curiosity and led me to examine this on the P-39 is the strange and extreme trim change that occurs now in transitioning the model into landing configuration. Not much pitch change occurs on gear deployment, basically similar to what I understand about the real aircraft , but flap deployment at normal pattern entry speeds now demand almost full forward stick movement to prevent the nose from skying up. Pitch up on flap deployment is a common trait of (generally) high wing aircraft, but low wing aircraft generally pitch down on flap deployment. The reason and driving force is the location of the Center of Lift in relation to the Center of Gravity location. The Center of Lift moves further behind the C of G on flap deployment. The pilot being concerned with landing and slowing the plane must counter with some nose up trim to not over speed his approach. Having said all of this the P-39 with its unique configuration with its mass in close proximity to the C of G and C of L should likely experience little trim change in transitioning to landing configuration. Now the rest........

I have searched for performance curves on the P-39¦s Pitch Rate to further support my point with hard data. However at this writing I've haven't some across those, and time is marching on. If any one has seen 'em I'd appreciate a copy or forward them with my sincere thanks.

The only definitive reference I can cite right now is from America's 100,000 by Francis Dean, which refer to pilot reports. Many regular contributors to this forum have this reference; it only contains the Basic curves for power, climb, roll, and endurance.

I'll start this bug report and continue to try to turf up the "P"'s on pitch rate.

I anticipate comment, please be nice/i/smilies/16x16_smiley-happy.gif , and also keep in mind that if comparisons are brought forth on turn rate as a point or counter point; pitch rate is not the same as rate of turn. Pitch rate along with roll and the planes configuration deal with placing the machine in a turning attitude, or any change in attitude for that matter. Turn (rate of) is more determined by speed, the radius, G load, wing loading, power loading, and other dynamics which influence the airframe at any given angle of attack.

I'll also offer that what I'm talking about will make the '39 much more prone to stall and spin if you bank and yank it, as you can do now with the 1.1b FM. As it is the machine is out of character and benign as regards pitch rate and stall behavior in the main.

Excerpt, A's 100k, page 201:

"An outstanding characteristic of the P-39 was extreme control sensitivity; A P-39D fore and aft stick movement of only one inch would change the wing lift coefficient from a high speed value of 0.20 to a near stall 1.40 with a normal airplane center of gravity location. One pilot put it this way "you move the stick on the P-39 one eighth of an inch and you could throw it into a spin before you knew what was happening." In addition stick forces were light. At normal center of gravity location fore and aft stick force per G was less than 2 pounds, where the normally allowed minimum was 3 pounds per G."

Lastly, how about adjusting the control input in the FB setup page? Since FB came out, for the P-39 my pitch settings have been 100 pct across the page with little dead zone and no filter.

All the Best:



BPO5_Jinx
C.O. Replacement Air Group
Birds of Prey. 16th GvIAP
http://www.birdsofprey16thgviap.com
http://www.soaridaho.com/Schreder/RS-15/N50GL.html

XyZspineZyX
08-30-2003, 01:51 AM
I agree, and now you just mash the stick against the stop . . . no finesse needed . . . any need to worry about excess angle of attack. . . This isn't new since the patch though, this came along with FB.

S!
TX-EcoDragon
Black 1
TX Squadron XO
http://www.txsquadron.com

Reserve Pilot Aircraft #2 of Gruppo 313
Pattuglia Acrobatica Virtuale
http://www.pav-amvi.it

http://www.calaggieflyers.com/



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XyZspineZyX
08-30-2003, 02:12 AM
couldnt agree more. 190s yaks and mig3s are just as bad as the 39 no sense of stick pressure at all at any speeds. Hopefully they will dull them down alot and make the sim have semi descent realistic fms.

definatly has the best gunnery and graphics


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Good dogfighters bring ammo home, Great ones don't. (c) Leadspitter

XyZspineZyX
08-30-2003, 02:14 AM
I have NACA reports on the flying characteristicis of the P-39. All in PDF format. They are as follows:

Flying qualities of the P-39D
Effects of compressibility on the P-39N
Variation of drag coefficient for the P-39N
High speed longitudinal control of P-39N
Measurements of pressure distribution on wing of P-39N

It's a lot, over 8 megs. But I'll send them to you if you want them.



Regards,

SkyChimp

http://members.cox.net/rowlandparks/corsairs.jpg


Message Edited on 08/30/0305:23AM by SkyChimp

XyZspineZyX
08-30-2003, 02:28 AM
Actually, I think this one would fill the bill nicely:

"High-speed longitudinal stability and control of the Bell P-39N-1 airplane as calculated from propeller-off tests of a 0.35-scale"
Robert C. Robinson and Angelo Perone
NACA RM-A6L27
1947


Download it here:

http://naca.larc.nasa.gov/reports/1947/naca-rm-a6l27/naca-rm-a6l27.pdf

Regards,

SkyChimp

http://members.cox.net/rowlandparks/corsairs.jpg

XyZspineZyX
08-30-2003, 04:29 AM
~S! SkyChimp and thanks, much appreciated.

Those are applicable curves that speak to rate of pitch, stability, and rate of change through the machine speed range.

I'm not an engineer but looking briefly at the curves, they seem to confirm the elevators are very effective to high mach numbers, the curves stay together with little diversion. I intend to spend some more time with them.

Here's the science, I'd be interested if the info therein will be put to use, eventually.

They are also saying after the fact, that if the factory increased the span of the bird's horizontal stab it improves the machines stability in pitch through the speed range and would thereby reduce the tendency of stick reversal at high G high speed turns and dive pull out, without degrading rate changes to any large degree. Translated this change would give the pilot more feedback as the machine apprached the critcal alpha.

In the sim we would hear airframe shake and maybe see head shake from vibration and some degradation of aileron response, i.e the plane would want to start to dutch roll.

I would like copies of the files, one can never have too much info of this type. I'll send you a PM.

Regards:





BPO5_Jinx
C.O. Replacement Air Group
Birds of Prey. 16th GvIAP
http://www.birdsofprey16thgviap.com
http://www.soaridaho.com/Schreder/RS-15/N50GL.html

ZG77_Nagual
08-30-2003, 04:56 AM
looks like elev was maybe closer pre patch.


http://pws.chartermi.net/~cmorey/pics/p47janes.jpg

XyZspineZyX
08-30-2003, 04:14 PM
With the kinds of moves I've seen countless P-39s make online, I don't see how you can complain about elevator response. P-39s, particularly the N1s, are able to literally loop circles around 109s, which see control stiffness starting at just 400kph in dives.

In a 109 you cannot follow a P39 if it dives and then raises the nose at combat speeds. He'll stick the nose up and *viff* he's GONE. And there's nothing you can do about it. Chances are, he'll be coming back down the other side of the loop onto your six before you can even get 45 degrees nose up.

XyZspineZyX
08-30-2003, 04:34 PM
Salute

The 109 should not be able to follow the P-39 at high speeds.

The 109 has test documented lack of elevator response at high speeds. This in multiple tests and through multiple models.

Additionally, with the exception of perhaps the F4, the P-39 has lower wingloading than all the 109's. The degree of this advantage increases dramatically with the later model P-39Q-10 versus the 109G10, or K4.


RAF74 Buzzsaw

ZG77_Nagual
08-30-2003, 05:19 PM
I hope the documentation in this thread has been emailed to Oleg. the opening statement is one of the most articulate and well-formulated ones I've seen.

http://pws.chartermi.net/~cmorey/pics/p47janes.jpg

XyZspineZyX
08-30-2003, 05:59 PM
~S! All:

I'd be happy to email to Oleg, I don't have the addy though ( I's certainly like to have it).... or Skychimp can do it and recieve the credit, he supplied the data, I just started the process on this one. Again my thanks to SkyChimp and others.

To Stiglr:

You'll for sure see a quicker change in pitch from the Snakes.... BUT what you will also see much more of, is the start of manuever which fails because the pilot pulled a little too hard. In the main , just my take on this, you won't see a commanding advantage given the the '39's, you see more stall/spin right in front of you. The 109's still have a great excess thrust... read accel, and the ability to out run the '39's in certain configs. The point of the thread and my point is historical accuracy, if that is to be fullfilled. Well flown 109's will win engagaments, so will the 39's if well flown. My point is not about unfair advantage at all. I hope you can understand that.

Personally ,I wish to experience what a '39 was like with all its vices up front and center, and the same with the other aircraft whatever model or make.

If corrected the pitch rate will be quicker, much quicker... the result is the pilot will have the ability to immediately depart the plane from with too quick a pull. As it is, no finesse required, I just put the stick back to its fullest aft movement and hold it...... the machine won't stall, until it slows, by that time my view in front has generally improved. Its way off the mark. At the end of the day I think you and other 109 drivers get some advantage/strenghts back in your favor.

The elevator reponse as modelled on the 39 is way off, the data/curves show that.

Regards:



BPO5_Jinx
C.O. Replacement Air Group
Birds of Prey. 16th GvIAP
http://www.birdsofprey16thgviap.com
http://www.soaridaho.com/Schreder/RS-15/N50GL.html

XyZspineZyX
08-30-2003, 06:52 PM
~S!

PM sent.

Regards:



ZG77_Nagual wrote:
- I hope the documentation in this thread has been
- emailed to Oleg. the opening statement is one of the
- most articulate and well-formulated ones I've seen.
-
-
-
<img
- src="http://pws.chartermi.net/~cmorey/pics/p47jane
- s.jpg">
-



BPO5_Jinx
C.O. Replacement Air Group
Birds of Prey. 16th GvIAP
http://www.birdsofprey16thgviap.com
http://www.soaridaho.com/Schreder/RS-15/N50GL.html

XyZspineZyX
08-30-2003, 07:51 PM
RAF74BuzzsawXO wrote:
- Salute
-
- The 109 should not be able to follow the P-39 at
- high speeds.
-
- The 109 has test documented lack of elevator
- response at high speeds. This in multiple tests and
- through multiple models.
-


Can you post these multiple tests, Buzzsaw, or at least provide us with an exact reference (ie. 109 and P-39 types used in these evalutations).

What I have on 109 elevator response at high speeds (109F dive evaluation performed by Lukas Schmidt) shows that the pullout (and horizontal flying state) from a 906 kph, 70-80 degree vertical dive could be easily done on a tested 109F witin a matter of ~800m altitude after the pullout was initaited.

http://vo101isegrim.piranho.com/FB-desktopweb.jpg
'Only a dead Indianer is a good Indianer!'

Vezérünk a Bátorság, K*sérµnk a Szerencse!
(Courage leads, Luck escorts us! - Historical motto of the 101st Puma Fighter Regiment)

Flight tests and other aviation performance data: http://www.pbase.com/isegrim

Message Edited on 08/30/0308:54PM by Vo101_Isegrim

XyZspineZyX
08-30-2003, 11:20 PM
Oh yes... where did this false notion of the 109 controls feeling as if stuck in cement ever come from? Certainly not from German pilots who flew them! Or perhaps the cement was thin and wet?


Neal

XyZspineZyX
08-31-2003, 02:48 AM
I never heard that Me-109s had elevator problems. Aileron problems at high speed maybe, but not elevator problems AFAIK.

Regards,

SkyChimp

http://members.cox.net/rowlandparks/corsairs.jpg

XyZspineZyX
08-31-2003, 02:55 AM
Hmm alot of information and documentation to this topic.


All I know is since FB if I've got a P-39 engaging me while I'm in a 109 except the later crotch rockets like AS, G-10,14.K-4 and I didn't start the engagement with enough energy over him to pull away in a climb I just give up.

It will out run you, it will outdive you, and it will out turn you, it will even out zoom climb you. Your only hope it is a sustained climb and hope he doesn't get any potshots in.

http://www.redspar.com/redrogue/CraggerUbisig.jpg

About after 30 minutes I puked all over my airplane. I said to myself "Man, you made a big mistake." -Charles 'Chuck' Yeager, regards his first flight

XyZspineZyX
08-31-2003, 12:02 PM
SkyChimp wrote:
- I never heard that Me-109s had elevator problems.
- Aileron problems at high speed maybe, but not
- elevator problems AFAIK.
-
- Regards,
-
- SkyChimp

The other way, chimp. Elevator was heavy, ailerons and rudder were light. Still, the elevator control was in order of the P-51s in terms of heaviness.

http://vo101isegrim.piranho.com/FB-desktopweb.jpg
'Only a dead Indianer is a good Indianer!'

Vezérünk a Bátorság, K*sérµnk a Szerencse!
(Courage leads, Luck escorts us! - Historical motto of the 101st Puma Fighter Regiment)

Flight tests and other aviation performance data: http://www.pbase.com/isegrim

XyZspineZyX
09-01-2003, 01:08 PM
I think the elevator stiffness issue comes from Cpt Eric Brown in book "Wings of the Luftwaffe". He states:

"At cruising speed of 240mph (386km/h) the Gustav was certainly delightful to fly, but the situation changed as speed increased: in a dive at 400mph (644km/h) the controls felt as though they had seized!"

I believe that the elevator stiffness kicks in at too low a speed (perhaps 500-550km/h would be a more realistic number)

Also it must be remembered that Brown was of small stature and perhaps not as strong as some.

XyZspineZyX
09-03-2003, 02:05 PM
Good posts.

I agree the P-39 should have a better "instantaneous" pitch ability and bring back the nasty stall/spin characteristics of the Cobra. It was known to depart if pushed - and not pushed that hard either.

In IL-2 the P-39 was to me (and my squad) a respected aircraft. Rugged with great firepower it could be dangerous in the right hands. We had great respect for pilots who tackled the challenges of the P-39 and proved worthy opponents.

The P-39 now has a somewhat bizzare FM IMHO with odd climb, roll and energy bleed elements. Hopefully the dev team will latch on to this info and make some changes for the next patch - thanks for the info guys S!

JG5_UnKle

"Know and use all the capabilities of your airplane. If you don't sooner or later, somebody who does, will kick your ***"


http://homepage.ntlworld.com/victoria.stevens/jg5_logo.jpg

XyZspineZyX
09-03-2003, 02:11 PM
Strange...every Patch since IL2 changed the FMs dramatically..and always Mr O. said: "It is realistic"...



Message Edited on 09/03/0303:12PM by VVS-Manuc

XyZspineZyX
09-03-2003, 03:22 PM
LeadSpitter_ wrote:
- couldnt agree more. 190s yaks and mig3s are just as
- bad as the 39 no sense of stick pressure at all at
- any speeds. Hopefully they will dull them down alot
- and make the sim have semi descent realistic fms.
-
- definatly has the best gunnery and graphics
-

Hopefully based on what? You have written that BS no often enough to spill the donuts and yet you fail to document one single unrealistic manouver or "bat turn".

Semi decent FM? FOr the first time FB bothers to produce something like high gee manouvers. Yes, an aircraft with Bf wingloading needs 440 km/h to pull 7 g without stalling, FW wingloading needs already 460 km/h. If you read of pilots blacking out or them performing those load factors it must have happened above that speed /i/smilies/16x16_smiley-wink.gif and without decent elevator that's not possible.

Pray tell why wouldn't a P-39 7 g curve at 500 km/h be just as tight as Yak-3 7 g turn? In fact P-39 will turn inside Yak-3 at this speed because it flies higher lift factor due to wingloading and will bleed speed faster in tight manouver (thus cutting inside). It will also loose the E-advantage in continued manouvering faster. Exactly this is what happens at the moment. The only escape for Yak is to pull higher gee, higher lift factor, same speed bleed -> blackout. Or use the coming E-advantage. What you're seeing for the first time starts to resemble a real behaviour. Pity, if b!tching and moaning gets noted and we end up with the lazy as flight model with DC-3 elevator fm.

-------------------------------------
http://people.freenet.de/hausberg/schimpf.gif

XyZspineZyX
09-03-2003, 03:52 PM
Ugly_Kid wrote:
- What you're seeing for the first time starts to
- resemble a real behaviour. Pity, if b!tching and
- moaning gets noted and we end up with the lazy as
- flight model with DC-3 elevator fm.

It feels like that has happened somewhat already. Things feel heavier and a bit more sticky, more like the crap that was IL2 thanks to the ill-informed crying that FB was "too easy" merely because planes could accelerate and retain E like they should.

XyZspineZyX
09-03-2003, 03:54 PM
JG5_UnKle wrote:
- The P-39 now has a somewhat bizzare FM IMHO with odd
- climb, roll and energy bleed elements. Hopefully the
- dev team will latch on to this info and make some
- changes for the next patch - thanks for the info
- guys S!

I was under the impression that the P-39 had excellent E retention due to it's highly aerodynamic form. (then again, so did the FW-190, but try to get Oleg's followers, to admit that. lol)

XyZspineZyX
09-03-2003, 03:59 PM
Yes, some of the issues exist on the arcade side of the spectrum like no spins etc.. Then on the otherhand 1.1 is IMHO big leap forward and not backwards. I am not talking about the special effects stalls and spins etc. I mean the average movement through the air and particularly high speed behaviour, heavy wingloaded aircraft FM. The average speed in the fight has increased quite a lot in FB and even more with 1.1 (compared to IL-2 FW fights with take-off flaps), the thousand circles turnfights seem to be history and it does not seem to suit some...

-------------------------------------
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Message Edited on 09/03/0304:34PM by Ugly_Kid

ZG77_Nagual
09-03-2003, 04:08 PM
I agree Ugly_Kid - soon as i start thinking something is way off - I get online against other types and see the relative performance is very good - from everything I've been able to gather.

http://pws.chartermi.net/~cmorey/pics/p47janes.jpg

XyZspineZyX
09-03-2003, 05:14 PM
ZG77_Nagual wrote:
- I agree Ugly_Kid - soon as i start thinking
- something is way off - I get online against other
- types and see the relative performance is very good
- - from everything I've been able to gather.

But some things are off as Ugly_Kid suggests. This thread points to an obvious one with the P-39's lack of stall and spin. Whatever has been done to the FM overall in FB and in 1.1, some planes just don't seem to have the flight characteristics that they were historically noted for having.

An N-1 pilot can literally yank and bank without worrying about flat spinning it at all. This changes how it is flown. It matters much less how a turn is entered, andthe slip indicator can be pretty much ignored. The lack of elevator sensitivity now also makes it an extremely stable gunplatform from long ranges.

http://home.cogeco.ca/~jkinley/rcafpost.jpg

ZG77_Nagual
09-03-2003, 06:20 PM
These things are true- but you are talking actual enhancements to the 39s performance at higher speeds (in skill hands of course) with a twitchiness more like what we see in the 190 - if I'm not mistaken. Previously the p39 would stall out of turns that were not necessarily sharp - that is the stalling was there - but not the turn - also it lost energy very quickly and could not regain it. This does not fit with vvs historical accounts which say this aircraft had excellent e retention/aeordynamics (the brits criticized it because it did not DEcelerate quickly.

So anyway - If I'm right - you are looking to make the stick more sensitive and, also, improve high speed elevator response - am I right?

The other question is roll rate - which I've seen no figures for with regard to the models in the game

http://pws.chartermi.net/~cmorey/pics/p47janes.jpg

XyZspineZyX
09-04-2003, 12:15 AM
~S!

Nagual, your are correct, the point and focus is flight control response, in partricular elevator response, on the P-39. That's all, roll rate is covered elsewhere.

This will not change the planes dynamics are far Critical alpha, E retention, etc, etc., What will happen a pilot who makes a mistake such as pulling too hard, he'll have the ability to depart the plane. He'll get bite! More sensitve in pitch simply, not the almost non repsonsive elevator response as seen now as speed builts up. ( To what degree? I don't know the rate is there in the curves.)

We have the Flight test data and it has been forwarded. The is more to go as well.

Let's please not see anecdotal comparsion of machines here, those issues appear in other threads.

I respect and appreciate the input to date, but lets keep to the subject please. I'm not in command of data nor pilot reports and such on Yaks, La's, Migs, nor have I researched the LW machines to the degree that I have on the P-39.

At the end of the day it will be the developers who make the call, the best we can do is to assist with the facts as much as possible.

One of the facts I found interesting in reviewing some of these curves, are the changes made to the N1's.

As an example, I earlier recited from a quote in A's 100k that the Elevator pressure of the D model was under 2 lbs per G. The N1's was in the range of 3.3 to 4.0 lbs per G. This still means that the initiation of a high G turn or dive pull out is still a light and singled handed event for the P-39 pilot. This would translate to the pilot having a tremendous effect and control of the machine's E retention or Bleed, as the case maybe.

Thanks to all, let's see what response we receive.

Regards:



BPO5_Jinx
C.O. Replacement Air Group
Birds of Prey. 16th GvIAP
http://www.birdsofprey16thgviap.com
http://www.soaridaho.com/Schreder/RS-15/N50GL.html

XyZspineZyX
09-04-2003, 04:47 AM
Just on a random side note; excessive elevator lightness was a problem that the P-47 suffered from heavily in FB 1.0. Pull back hard on the stick at speed, and you a very suddenly flying with a 30 degree Angle of Attack. That's a pretty quick, and potentially nasty, stall. You can see it in the flyby view relatively easily. If you pull hard, the P-47 is quickly pointing in a very different direction from the one it is flying in.

Note: I am not stating whether or not this is accurate or not, and really do not wish to start a debate on this subject. Rather I am tryign to point out an aircraft that is modelled so that one can experience the problems on excessively light controls.

Harry Voyager

http://groups.msn.com/_Secure/0YQDLAswcqmIpvWP9dLzZVayPXOmo6IJ16aURujNfs4dDETH84 Q6eIkCbWQemjqF6O8ZfvzlsvUUauJyy9GYnKM6!o3fu!kBnWVh BgMt3q2T3BUQ8yjBBqECLxFaqXVV5U2kWiSIlq1s6VoaVvRqBy Q/Avatar%202%20500x500%20[final).jpg?dc=4675409848259594077

XyZspineZyX
09-05-2003, 02:53 AM
~S!

Thanks Harry. Bump.



BPO5_Jinx
C.O. Replacement Air Group
Birds of Prey. 16th GvIAP
http://www.birdsofprey16thgviap.com
http://www.soaridaho.com/Schreder/RS-15/N50GL.html

XyZspineZyX
09-05-2003, 01:28 PM
The P-39 suffers from the same elevator problems like the FW 190 in Il-2 and FB 1.0. It should be lighter, but also very prone to stalls & spins, even at high speeds. (The differece to the FW is that the FW hardly spins and it's easy to recover while the P-39 is very dangerous)

Also read:

The Best of the Breed
by Col. "Kit" Carson

"High speed stalls under "g" load were a little vicious and could be a fatal handicap in combat. If the airplane was pulled in tight and stalled at high speed at 2 "gs" or more with the power on, turning right or left, the left wing would drop violently without warning and the airplane would flick onto its back from a left turn. I scored against a 190 under such circumstances. The message was clear, don't stall it.

Our own Bell P-39 Aircobra would do the same thing." (!)

XyZspineZyX
09-05-2003, 09:27 PM
~S! BUMP!!!

XyZspineZyX
09-26-2003, 01:42 AM
Great find Willey. Bump!

ZG77_Nagual
09-26-2003, 02:08 AM
The above quote refers to a 190 flight eval - not a p-39 - just to be clear.
Great thread.

http://pws.chartermi.net/~cmorey/pics/p47janes.jpg


Message Edited on 09/25/0309:09PM by ZG77_Nagual

XyZspineZyX
09-26-2003, 11:49 AM
Interestingly "Attack of Airacobras" from Loza says that VVS issued an order to limit dive speeds and consequent pull-ups to 420 mph because they had cases of severely bent elevators and also loss of complete tail section. The elevator was inadequately designed with too large spacing between the stringers. Taking the almost tearshedding patriotic style of the book into account I would not take anything with the face value but would be good to know whether this had a ring of thruth in it. (There was also a reference to this particular order in the book)

-------------------------------------
http://people.freenet.de/hausberg/schimpf.gif

XyZspineZyX
09-27-2003, 04:33 PM
~S!

Ugly Kid, I refered to this in an earlier post, I found other references which indicate the factory addressed this by strengthening the empenage. It maybe somewhere in Attack of Aircobras, not sure about my memorary tho.

Regards:



BPO5_Jinx
C.O. Replacement Air Group
Birds of Prey. 16th GvIAP
http://www.birdsofprey16thgviap.com
http://www.soaridaho.com/Schreder/RS-15/N50GL.html

XyZspineZyX
09-27-2003, 06:23 PM
why shhhhhytcan the p39 but leave the stupid *** movements people use online with the 190 yaks mig3u and lagg


definatly the worst part of the game the stick yanking fish flopper constant roll with no red or black out THIS NEEDS FIXING and the game would be so much better

btw p40m accel top speed and roll are wrong http://ubbxforums.ubi.com/infopop/emoticons/icon_smile.gif the d27 roll is wrong as well im sure you still have the charts p40m outrolls the p39 at all alts http://ubbxforums.ubi.com/infopop/emoticons/icon_smile.gif


http://mysite.verizon.net/vze4jz7i/ls.gif

Good dogfighters bring ammo home, Great ones don't. (c) Leadspitter

XyZspineZyX
09-27-2003, 07:39 PM
SkyChimp wrote:
- I have NACA reports on the flying characteristicis
- of the P-39. All in PDF format. They are as
- follows:
-
- Flying qualities of the P-39D
- Effects of compressibility on the P-39N
- Variation of drag coefficient for the P-39N
- High speed longitudinal control of P-39N
- Measurements of pressure distribution on wing of
- P-39N
-
- It's a lot, over 8 megs. But I'll send them to you
- if you want them.

Ooh, Skychimp! It´s a deal... I wasn´t the one who asked, but I´d love to have a look at those manuals... can I?

Please PM me either here or at il2skins (same nick) so I can send you my e-mail address.

Thanks in advance...

GreyBeast_P39