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XyZspineZyX
08-13-2003, 05:53 PM
Oleg Maddox wrote:

"Another notice is that we do not accept the bug reports like "this plane flying bad! I think it should fly better!" without technically documented arguments on enginiring level of knowledge."

So let's all pull together adn post enything and every thing that supports the FACT that the P-47 was a one of the best fighters in WWII.


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XyZspineZyX
08-13-2003, 05:53 PM
Oleg Maddox wrote:

"Another notice is that we do not accept the bug reports like "this plane flying bad! I think it should fly better!" without technically documented arguments on enginiring level of knowledge."

So let's all pull together adn post enything and every thing that supports the FACT that the P-47 was a one of the best fighters in WWII.


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XyZspineZyX
08-13-2003, 07:38 PM
bump...this is a worthy post,but I don't have time to post anything detailed yet....I'm sure there are plenty that can. Pesonally, I feel the engine DM is still too sensitive,and the roll rate is too slow,but these are just "impressions" I have....nothing concrete.

47|FC
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XyZspineZyX
08-13-2003, 08:53 PM
I just flew on a 1942 server. I started with the Fw190A-5, and I had some good fights at 6000 meters against a MiG-3U. I then decided to take the P-47 for a spin. What can I say? This planes is so smooth! It's heigh weight gives it an incredible momentum! I managed to down a MiG-3U and a La-5FN with ease! Being a Fw fanatic, transfering the tactics I use flying 190 onto the P-47 was a piece of cake! The .50's creates some serious damage! If the rollrate gets any better on this baby, it will be a very good match for my D-9! P-47, an awesome aircraft! Finally!!/i/smilies/16x16_smiley-happy.gif

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XyZspineZyX
08-13-2003, 09:04 PM
Roll rate not right though on Jug /i/smilies/16x16_smiley-sad.gif

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XyZspineZyX
08-13-2003, 09:21 PM
Heuristic_ALgor wrote:
- Roll rate not right though on Jug /i/smilies/16x16_smiley-sad.gif
-

Don't you ever dreamed that a P-47 can roll like a Fw190 or a La7? But, i agree with you that the P47 have a litle better roll rate.

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XyZspineZyX
08-13-2003, 10:37 PM
I know a mechanic from the actural 310th fighter squad and he served in the Pacific, anything you wanna know about the P-47 he can tell you, but you have to go to him..

He said that the engineers calculated a dive that a P-47 did once, and from about 30,000 feet to 3,000 feet he when about 687 mph.. and that is just what Tex told me..

The plane was so messed up that they stripped it for parts and scrapped the rest. The pilot had to put his feet on the instrument panel and wait until the plane was in thinker air before he managed to pull up..

If Oleg would just talk to Tex once, he would see that no freekin' book of his can beat what Tex already knows..

XyZspineZyX
08-13-2003, 10:56 PM
Maybe we will never get the correct roll rate. Surely by now Oleg and his team would have take care of this problem. Maybe they think they know something all the the experts dont. Maybe they disagree with all the plentiful data available for the P-47s rollrate. Or maybe they are just biased towards Russian and German aircraft. It is just rediculous how frequently the P-47 loses its controls and engine with one hit from a MG round. Not to mention the fuel leaks. This happens on just about every flight.


While the P-47s damage model is worse the 190s are still flying tanks. Say what you want but the 190 DM is the most overmodeled part of the game IMO.


The P-47Ds cruise speed is 350mph and the top speed is about 430mph. These are almost unatainable in level flight it should not take forever to reach your cruise speed thats why its called cruise speed. Keep in mind that this is mph not kph. If you reach the cruise speed in level flight post your track here, Id like to see how long it took ya to reach it.



Message Edited on 08/13/0305:57PM by VMF-214_HaVoK

XyZspineZyX
08-13-2003, 11:14 PM
maybe Oleg just have more reliable information about flying characteristics of the P47...

I've been a passionnate about warbirds for more than twenty years, and i never heard about the marvellous rollrate some people are discussing here...

Maybe i wasn't well informed after all...

i'll have to find out now, can't stay like this without knowing...

XyZspineZyX
08-13-2003, 11:14 PM
The P-47D-27 in FB should be modelled with a roll that corresponds to a 50 lb stick force, just as all other aircraft are. To leave it with a crippled roll rate is inexcusable.

It's clear the roll rate of the FB D-27 is much closer to the 30 lb performance in the now "famous" NACA report. (In reality, it isn't even that good.)

So what's the excuse? No roll charts available that show performance with a 50 lb stick force? Poor excuse.

Now that we know how the plane performed at 30 lbs, all we need to know is its peak roll rate at 50 lbs to come up with a proper graph.

The P-47D-25 had the same PEAK roll rate as did the P-47D-22. The D-22 was the same as the C-1. And we know the C-1 topped out at 85 degres per second. I'd wager the P-47D-25, D-27 and D-30 were pretty damned close to eachg other.

Therefore, all we need to do is extend the initial line on the 30 lb chart to 85 degrees, and allow it to drop off at the same rate as it does at 30 lbs, and we have the 50 lb performance.

http://members.cox.net/rowlandparks/50lb_roll.jpg


Oleg should model the D-27 to this standard.

Oleg has no excuses for leaving the P-47 crippled in this regard. None whatsoever.



Regards,

SkyChimp

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XyZspineZyX
08-13-2003, 11:27 PM
oh...

you're wrong, the formula for the effect of control surfaces related to the stick pressure isn't linear...

i thought you knew it, you seemed to be well informed in aeronautics calculations...

XyZspineZyX
08-13-2003, 11:33 PM
S!

Instead of posting technical data that can sometimes be disputed, cant you get a AVI file of a P47 at an Airshow doing a roll and Post a link to it here.

I was at the Flying Legends airshow at Duxford UK, and I can vouch for the roll rate being way wrong as I have seen the P47 roll for real.

Bear in mind that 60 year old aircraft doing a roll these days is done way within minimums and is no where near actual combat rates.

It still rolled a hell of a lot faster than the ones in FB though.

XyZspineZyX
08-13-2003, 11:45 PM
Hoarmurath wrote:
- oh...
-
- you're wrong, the formula for the effect of control
- surfaces related to the stick pressure isn't
- linear...
-
- i thought you knew it, you seemed to be well
- informed in aeronautics calculations...
-
-

Is this directed at me?

The chart I posted above would be correct.

The original chart indicates 30 lbs of stick force was sufficient to fully deflect the aileron from 130 mph to 200 mph. Applying 50 lbs of stick force at these speeds would be wasted effort as the ailerons would be at the mechanical limitation of their travel.

At speeds of over 200 mph, pressure would have been sufficient to start to reduce deflection with a 30lb stick force. Therefore, a higher stick force would be needed to maintain full deflection at speeds over 200 mph.

The P-47D-25 was capable of 85 degrees per second with 50lbs of force (the P-47D-27 surely would have been similar). Therefore, one only needs to extend the 30 lb line to a point where it peaks at 85 degrees per second. Once 85 degrees per second is achieved, the rate begins to drop. It would more or less drop at the same rate as it does at 30 lbs.



Regards,

SkyChimp

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XyZspineZyX
08-13-2003, 11:56 PM
It is slow. I rarely break even Cruise Speed except in a Dive. Many planes in IL2 are like this, except for some that are far faster than they should be. It feels like they took the P47 data and just changed Mph to Kph and left the numbers the same. Something to look into I think for those with the time.

Fish itchy

XyZspineZyX
08-13-2003, 11:58 PM
What the? A petition to just change the P-47? Isn`t that just incredibly selfish? What about the rest of the sim? Why not play it for at least ONE week first before all this Holier than thou other planes rubbish?

I hate to think what would happen if Olegg did listen to JUST you guys...
We might as well call the simulation (made by you guys)` P-47 and All Else Don`t Matter!`


/i/smilies/16x16_smiley-mad.gif





"Tis better to work towards an Impossible Good, rather than a Possible Evil."

SeaFireLIV.

Message Edited on 08/13/0310:59PM by SeaFireLIV

XyZspineZyX
08-14-2003, 12:05 AM
ok, i understand this :

"The P-47D-25 was capable of 85 degrees per second with 50lbs of force (the P-47D-27 surely would have been similar)."

then i don't understand this :
"Therefore, one only needs to extend the 30 lb line to a point where it peaks at 85 degrees per second. Once 85 degrees per second is achieved, the rate begins to drop. It would more or less drop at the same rate as it does at 30 lbs."

i supposed you did a mistake in the first sentence?

XyZspineZyX
08-14-2003, 12:18 AM
Hoarmurath wrote:
- ok, i understand this :
-
- "The P-47D-25 was capable of 85 degrees per second
- with 50lbs of force (the P-47D-27 surely would have
- been similar)."
-
- then i don't understand this :
- "Therefore, one only needs to extend the 30 lb line
- to a point where it peaks at 85 degrees per second.
- Once 85 degrees per second is achieved, the rate
- begins to drop. It would more or less drop at the
- same rate as it does at 30 lbs."
-
- i supposed you did a mistake in the first sentence?
-
-
-
-

I don't see a mistake. The red line on the chart I posted illustrates my statement.

Regards,

SkyChimp

http://members.cox.net/rowlandparks/SkyChimp2.jpg

XyZspineZyX
08-14-2003, 12:29 AM
This has been talked about since FB came out and nothing has changed.

Talking to deaf ears guys.

After 6 months development, the P47 roll appears untouched.

Skychimp has posted these legit numbers for quite some time now - if Oleg was interested he would have commented.

But, I hear nothing - again, talking to deaf ears.


S!
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XyZspineZyX
08-14-2003, 12:46 AM
Recon_609IAP wrote:
- This has been talked about since FB came out and
- nothing has changed.
-
- Talking to deaf ears guys.
-
- After 6 months development, the P47 roll appears
- untouched.
-
- Skychimp has posted these legit numbers for quite
- some time now - if Oleg was interested he would have
- commented.
-
- But, I hear nothing - again, talking to deaf ears.

Yeah I commented on this the other day and the posts appear to have gotten more coherent. In view of that and the fact that it has not changed(roll rate), I think we are possibly not going to get a change in this regard. I still have a slim hope since there are new patches coming. However, Oleg's Team seems resolute in their belief that because the JUG was so heavy and could carry a real bomb load, it could not roll the way Western data says it did.

One point about whatever data Oleg's team "IS" using to make the JUG FM. Most folks would like to know where is it? Can "we" go to a site on the web that has this data? I really would like to know. According to some, Oleg's team has in the past refused to divulge this information. I would "hope" that at this time in the development/sales process, he would feel secure in the full public release of this data to resolve this issue once and for all.

How about it Oleg? It could end this controversy and bashing quickly. Help us resolve this. Thanks.

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Message Edited on 08/13/0304:49PM by UCLANUPE

XyZspineZyX
08-14-2003, 12:54 AM
you should indicate this as a reference, rather than that 1952 study

http://naca.larc.nasa.gov/reports/1947/naca-report-868/


this report is much more precise, and definitely on topic...


well, when i have a look at this document, i find that my razorback should have a roll rate of about 80?/second at a speed of 220 mph at 3000m altitude...

when i check in game, with a P-47-D-10, i find myself closer to 90?/second, somewhat better than chart, but it seem still rather correct (i think the difference have more chances of coming from my measure than from real game data)...

so, what's the problem? isn't the ability to roll 360? in four seconds enough?

(by the way, the other infos i found about the jug roll rate give a lesser value for the D series with bubble canopy, something to do with an heavier wing, it seem to induce a 10% drop in roll rate)

XyZspineZyX
08-14-2003, 12:57 AM
Well so far the only 2 ppl that have contributed any thing to this thread worth while are Skychimp & Priller.
SC thnks for posting the data. Much more is neded however.
i Contact some one on maxwell AFB today and i think i have a point i the right direction. The actuall usaaf flight test studies are avalible to the public. There stored in the National Archives. i'm going to try and get my hands on as much of that information as i can.

And Priller, I'm sure Tex & My Grandfather know each other.
Pops worked mostly on T6 Texans but did work on the Jugs quite for a short time. In Korea he was working on F-86's in Osan-Ni with the 58thFG/310thFS. Ask him if he was with them in Korea as well.

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XyZspineZyX
08-14-2003, 01:06 AM
"Therefore, all we need to do is extend the initial line on the 30 lb chart to 85 degrees, and allow it to drop off at the same rate as it does at 30 lbs, and we have the 50 lb performance"


That is NOT a correct statement.. The relationship between the stick force and the roll rate at various speeds will NOT follow the assumptions you made..

XyZspineZyX
08-14-2003, 01:07 AM
Sorry I cannot contribute much more than an opinion but what would probably really help Oleg out is two or more reports that largely conclude the same thing that have relatively the same information provided. This way we have something of a scientific process going on where the results are checked, rechecked, and rechecked again. That way, if Oleg is using something that has erroneous data (there's all kinds of variables from a human error in the data to the plane not working quite the way it should and so on and so forth - we do know that no test is ever going to be exactly the same but things should be very similar under the same conditions).

Now I don't have the access to the resources or anything like that but it'd be great if you guys, instead of just posting the info on the forum, gathered what sources you could, provided it in a word or word perfect document, and e-mailed it to Oleg and team so that they have solid reasoning behind your argument, the cold hard numbers, and several reports to back it up.

Forgive me if this has already been done to no avail, but at the moment I see alot of facts being turned up that look like they are coming from very legitimate sources...but nothing that Oleg can just take from this forum and integrate into an updated FM.

As it stands, the P47 is better than it was before...I find it much more effective (a DM server by the name of WWII online pitted US aircraft against German ones and the P47 was doing quite nicely for me).

Good luck!

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XyZspineZyX
08-14-2003, 01:10 AM
On the deck, I could get the D-27 up to almost 310mph. This was with WEP.

At 7500 meters, the indicated airspeed was about 220 Mph.


Ill keep checking if you want me to, just tell me anything I need to know so it can actually be used(CEm on or off, stuff like that).


Fish itchy

XyZspineZyX
08-14-2003, 01:10 AM
i don't see the erroneous datas from Oleg...

The plane we have in the game comply almost exactly to the NACA datas...

i really don't see why you're complaining about its roll rate...

XyZspineZyX
08-14-2003, 01:26 AM
Hoarmurath wrote:
- you should indicate this as a reference, rather than
- that 1952 study
-
- <a
- href="http://naca.larc.nasa.gov/reports/1947/naca-
- report-868/"
- target=_blank>http://naca.larc.nasa.gov/reports/19
- 47/naca-report-868/</a>


Why? I'd trust actual test data over calculated data any day. You learn in high school science that first you calculate your theory, then test it to see if you are correct. Test results always supercede speculative calculations.

You don't need to calculate roll rate for the P-47. Actual tests have been done and the numbers are known. There is no need to reinvent the wheel.



- this report is much more precise, and definitely on
- topic...

Sure its on topic, but it just muddies the waters. Again, the exact figures are known from actual tests. You don't need to try and calculate it.



- well, when i have a look at this document, i find
- that my razorback should have a roll rate of about
- 80?/second at a speed of 220 mph at 3000m
- altitude...

Republic and USAAF tests indicate 85 degrees per second at approximately 250 mph. Fine and dandy. But roll in FB at faster speeds DO NOT correlate with actual test data. The rate drops off way too fast. At 375 mph, the P-47 rolls twice as slow as it should



- when i check in game, with a P-47-D-10, i find
- myself closer to 90?/second, somewhat better than
- chart, but it seem still rather correct (i think the
- difference have more chances of coming from my
- measure than from real game data)...

The roll at 250 mph IAS with the razorback is not the issue. The roll at higher speed is.

For instance, the P-47D-27 in FB does a 360 roll in about 11 seconds at 375 mph IAS. It should perform the roll in about 5.7 seconds.



- so, what's the problem? isn't the ability to roll
- 360? in four seconds enough?

You're new, or a regular using a different name. This issue has been discussed at length. Low speed roll is not the issue. At low speed, 250 mph, the roll in FB is FAIRLY accurate. The issue is at high speed. The rate of roll drops off too fast for all models of P-47 in FB. All models roll about twice as slow as they should at high speeds. Again, this is not calculated. This is a comparison of FB performance tests compared to roll charts relecting real test data.



- (by the way, the other infos i found about the jug
- roll rate give a lesser value for the D series with
- bubble canopy, something to do with an heavier wing,
- it seem to induce a 10% drop in roll rate)

Are you talking about the universal wing? Older models were retrofitted to that standard very early on. And the data I have reflects performance for planes with that type of wing.

But if you think that's right, then please post the sources, or a link to them.

The books I have reflect a peak roll rate of 85 degrees per second for the P-47D-25. In fact, the P-47N, a plane with longer, heavier wings than the D-25 rolled at 110 degrees per second peak.



Regards,

SkyChimp

http://members.cox.net/rowlandparks/SkyChimp2.jpg

XyZspineZyX
08-14-2003, 01:38 AM
Chimp, you should stop acting as your name implies


you should have clicked on the link rather that saying nonsense, it point to the same site YOU are refereeing with the 1952 document, but to a different document, wich is focused on aileron response...

if this document is not a reference, then yours is just BS...

really...

XyZspineZyX
08-14-2003, 01:39 AM
jtasker wrote:
- "Therefore, all we need to do is extend the initial
- line on the 30 lb chart to 85 degrees, and allow it
- to drop off at the same rate as it does at 30 lbs,
- and we have the 50 lb performance"
-
-
- That is NOT a correct statement.. The relationship
- between the stick force and the roll rate at various
- speeds will NOT follow the assumptions you made..


It is absolutely correct. It has to, jtasker.

Look at the original roll chart. The rise in the line from 130 mph to 200 mph reflects the rate of roll with a 30 lbs stick force. You can not increase this rate even if you apply 100 lbs of force! You can not do it because the aileron WILL NOT move any more. 30lbs FULLY deflects the ailerons in this speed range. They are at the physical end of their range of motion.

But at 200 mph, pressure on the ailerons becomes too great for 30lbs of force to overcome. Pressure begins to push the aileron back down (or up). Therefore, a higher force is needed. Applying 50lbs of force from 130 mph to 200 mph will do NOTHING to increase roll rate, but it WILL keep the ailerons fully deflected beyond 200 mph. Get it? And because of this, the roll rate WILL continue to increase with speed until even 50 lbs is no longer sufficient to keep the ailerons deflected.

When that speed where 50 lbs is no longer sufficient is reached, the roll rate will begin to drop off. And will continue to drop off as speed increases.







Regards,

SkyChimp

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XyZspineZyX
08-14-2003, 01:42 AM
Hoarmurath wrote:

- The plane we have in the game comply almost exactly
- to the NACA datas...

Wrong, it does not. The roll rate of the P-47D-27 in FB does NOT even correspond to the 30lb graph I posted.

Look for Machine's graph comparing FB values to the 30lb NACA chart. Roll at slow speed is close, but its too low at high speeds.

Oleg didn't get it right for 50 lbs, and he didn't get it right for 30 lbs either.


Regards,

SkyChimp

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XyZspineZyX
08-14-2003, 01:50 AM
Copperhead310th wrote:
- Well so far the only 2 ppl that have contributed
- any thing to this thread worth while are Skychimp &
- Priller.
- SC thnks for posting the data. Much more is neded
- however.
- i Contact some one on maxwell AFB today and i think
- i have a point i the right direction. The actuall
- usaaf flight test studies are avalible to the
- public. There stored in the National Archives. i'm
- going to try and get my hands on as much of that
- information as i can.
-
- And Priller, I'm sure Tex & My Grandfather know each
- other.
- Pops worked mostly on T6 Texans but did work on the
- Jugs quite for a short time. In Korea he was working
- on F-86's in Osan-Ni with the 58thFG/310thFS. Ask
- him if he was with them in Korea as well.
-
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- adron/</a>
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Tex, only served in WW2 in the Pacific, and he kept his pilot alive and his crew is the only full ground crew left from that squad, we must not argue about stupid stuff but make a valid point and post that, whinning does nothing and when these men overseas got hit, they would always say, "I did my job" and that is realitiy.

XyZspineZyX
08-14-2003, 01:54 AM
Hoarmurath wrote:
- Chimp, you should stop acting as your name implies
-
-
- you should have clicked on the link rather that
- saying nonsense, it point to the same site YOU are
- refereeing with the 1952 document, but to a
- different document, wich is focused on aileron
- response...
-
- if this document is not a reference, then yours is
- just BS...
-
- really...
-
-

Hoarmurath, this concept seems to be lost on you. I am NOT interested in generalities regarding aileron response. I am interested in SPECIFIC roll rates given a particular stick force. For the P-47, that data is KNOWN, YOU DO NOT NEED TO CALCULATE IT.



Here is a question, Hoar:
Will the P-47D-30 roll faster at 300mph with a 50lb stick force than it does with a 30 lb stick force?



Of course it will. There simply is no question. And to suggest, like some people have around here, that a 50lbs stick force is not possible, is ludicrous when that was the standard force used in tests to determine roll rate.


Again, perhaps a perusal of past post will enlighten you as to just what is being complained about here.



Regards,

SkyChimp

http://members.cox.net/rowlandparks/SkyChimp2.jpg

XyZspineZyX
08-14-2003, 01:54 AM
this is why i posted this url, it point to a document containing a chart at 50lb stick pressure...

this was my last intervention... i will leave you at your whining, it is really all that you are doing here...

you don't even look at documents posted by other people if they don't seem to agree with you, you just stick to yours, with the values you want (by extrapolation, as they are not really indicated the way you expose them)...

XyZspineZyX
08-14-2003, 02:08 AM
-SkyChimp wrote:
-
- Why? I'd trust actual test data over calculated
- data any day. You learn in high school science that
- first you calculate your theory, then test it to see
- if you are correct. Test results always supercede
- speculative calculations.
-
- You don't need to calculate roll rate for the P-47.
- Actual tests have been done and the numbers are
- known. There is no need to reinvent the wheel.
-
-
-

A few years ago, the Society of Experimental Test Pilots ran a flight test comparison of the F6F-5, FG-1D (Goodyear F4U), P-47D-40 and P-51D. Chief test pilot was John Ellis of Kal-Aero. Other pilots also participated.

The three radial jobs had versions of the R-2800 that produced appx. 2,000 hp, so differences in performance can be reasonably attributed to the airframe (and prop). The P-51 had a V-1650-9 Merlin rated at appx. 1,500 hp.

The P-47 had a Curtiss Electric constant-speed four-blade prop. The FG-1 and F6F both had Hamilton Standard three-bladed constant speed props (so only the airframe made the difference between these two). The P-51 had a Hamilton Standard Hydromatic four-bladed constant speed prop.

Because of the age of the aircraft, structural loads were kept to 6g max. Engines were fueled with 100LL, which limited MP by four inches on the radials. Power was limited to maximum continuous settings (except for
take-off & climb to 10,000 ft., when military power was used), superchargers were limited to low range. Altitude did not exceed 10,000 ft (so bomber escort altitudes were not reached).

Some of the findings:

CLIMB brake release to 10,000 ft.

Hellcat quickest at 4min 15 seconds, followed by the FG-1 at 4min 44 sec. However, the F6F required 100 lbs of continuous right rudder making it very tiring to operate. The P-47 trailed the FG-1 by a few seconds. The
P-51 came in last.

LEVEL ACCELERATION at 10,000 ft. using METO to max attainable speed

P-51 accelerated from 110 KIAS to 242 KIAS in 133 seconds.
P-47 accelerated from 105 KIAS to 223 KIAS in 130 seconds.
F6F accelerated from 100 KIAS to 220 KIAS in 115 seconds.
FG-1 accelerated from 100 KIAS to 230 KIAS in 162 seconds.

STALL normal (straight and level decelerating at 1 kt/sec.) and accelerated (constant 3g turn decelerating at 1 kt/sec.)
Aerodynamic warning:

Best--P-47, with buffet 5 kt above stall.
Worst--P-51, no buffet or other warning.
FG-1 and F6F buffeted 2 kts above stall.
Decreasing aileron effectiveness and increasing longitudinal stick forces
were noticeable in all except the FG-1.

Height loss, accelerated stall:
Best--P-47, 100 ft.
Worst--P-51, 500 ft.
FG-1 and F6F both 150 ft.

Behavior during accelrated stall:

Most predictable and controllable: P-47 and F6F. Both could be flown at will into the pre-stall buffet, which at no time was heavy enough to present problems with tracking, and held at maximum usable lift coefficient with ease. Sideslip became noticeable as wing heaviness correctible with rudder. There was little tendency to depart controlled
flight. The FG-1 suffered severe airframe buffet shortly before the stall, but at the stall there was a strong g-break and rapid right wing drop--no matter which direction the turn. Careful left rudder could prevent wing drop,
but then at the stall the aircraft became very unpredictable, bucking and porpoising, with a tendency to a sudden departure. The P-51 gave no warning whatsoever of an accelerated stall. At the stall, the aircraft departed with complete loss of control, achieving 270-degree of roll before recovery. Departure was accompanied by violent
aileron snatch strong enough to rip the control stick from the hand. In short, the P-51 suffered from a Part I deficiency.

SUSTAINED TURN PERFORMANCE at METO at 10,000 ft.

The F6F out-turned the other three by a conclusive margin (1g). The other three were all about the same.
Corner speeds of all were very close to the maximum level flight speed, implying very rapid energy loss when turning at the structural limit. The F6F was in light airframe buffet at 6g at Vmax; the P-47 experienced light buffet at 4.8g. The FG-1 and P-51 were buffet-free up to 6g.

MANEUVERING STABILITY stick forces/g at Vmax

FG-1--5 lbs/g (too light)
P-47--7.5 lbs/g (ideal)
F6F--12.5 lbs/g (barely acceptable)
P-51--over 20 lbs/g (excessive)

STATIC LATERAL DIRECTION STABILITY steady heading sideslips
All aircraft except the P-47 exhibited moderate or greater adverse aileron yaw. Worst was the F6F, followed by the FG-1 and the P-51.

ROLL PERFORMANCE

1g 360-degree right (left slower--F6F worst, P-51 best)
FG-1--81 deg./sec.
F6F--78 deg./sec.
P-51--75 deg./sec.
P-47--74 deg./sec.

3g 180 degree right (left slower--P-51 and F6F best, FG-1 worst)

P-47--66 deg./sec.
FG-1--58 deg./sec.
P-51--55 deg./sec.
F6F--48 deg./sec.

DIVING ACCELERATION 30 deg. dive from 10,000 ft., 5,000 ft. begin pull-up, level off at 4,000 ft.

Aircraft P-47 FG-1 F6F P51

Start Speed 110 kts 100 kts 100 kts 120 kts
Max Speed 350 kts 348 kts 315 kts 350 kts
Time 23 secs 32 secs 28 secs 25 secs
All aircraft except the P-47 needed retrimming during the dive.

AGILITY g capture of 3g target, held for 5 seconds.

G capture and hold was easiest in the P-47, predictable and accurate. F6F overshot the target by 0.2g. P-51 and FG-1 both overshot by 0.5g

Heading Change Time (180 deg at METO, 220 KIAS at 10,000 ft.)

FG-1--8.5 sec P-47--9.7 sec F6F--9.9 sec P-51--10.0 sec

AIR-TO-AIR TRACKING 210 KIAS at 10,000 ft. (straight & level into a 3g turn to the left building to 4g followed by a hard reversal into a 4g right turn.)

FG-1 best, followed by P-47, F6F and, trailing badly, the P-51. Lateral corrections in the P-51 were difficult thanks to the very high stick forces. During one run-thru, an effort at a longitudinal tracking correction that put 4.5g on the plane led to a sudden departure and spin.

Poor forward visibility in all aircraft (P-47 worst, FG-1 best) made air-to-air tracking difficult. Depressed sight-line aiming difficult to impossible.

AIR-TO-GROUND TRACKING (90-degree roll into a 30-degree dive from 200 KIAS at 5,000 ft. into a 3.5g right rolling pullout to a 90-degree heading change initiated at 2,500 ft.)

The P-47 was far and away the best, accelerating 125 kts in the dive, no retrimming required, with crisp control response. Accurate target tracking very easy. FG-1 next best. 100 kt. acceleration. Agressive lateral corrections required. P-51 similar to FG-1 in acceleration and
control response, but with heavier stick forces. F6F also accelerated 100 kts., but stick forces increased 20 lbs and rudder forces became so high they interfered with accurate target tracking.

THROTTLE & PROPELLER RESPONSE
MP response instantaneous. Hamilton Standard propeller response quick and positive. Curtiss electric prop (on P-47) sluggish in response, delaying RPM change by 3 seconds in a change from 2,000 rpm (cruise) and 2,550 rpm (METO).

Radial engines required pilot to manage cowl and cooler flap settings.
Merlin engine had automatic control of oil and coolant radiator flaps.

I susepct that the SETP know what they are doing. The P-47 is the game is better, but it STILL screwed up.

-Tom




<img src=http://a0.cpimg.com/image/68/87/21986920-f885-016800F6-.jpg>

XyZspineZyX
08-14-2003, 02:10 AM
Hoarmurath wrote:
- this is why i posted this url, it point to a
- document containing a chart at 50lb stick
- pressure...
-
- this was my last intervention... i will leave you at
- your whining, it is really all that you are doing
- here...
-
- you don't even look at documents posted by other
- people if they don't seem to agree with you, you
- just stick to yours, with the values you want (by
- extrapolation, as they are not really indicated the
- way you expose them)...
-


Hoar:

You think that report is new to members of this board? If you think so, I'll have to inform you that you are a day late and a dollar short.

I have that chart (and report). It's been posted ad nauseum at this site. The P-47 therein is a P-47C-1. We don't have a P-47C-1 in the game. We have a P-47D-27.

The P-47C-1 to P-47D-23 all had approximately the same roll rates at the same speeds. Their roll charts would look almost identical.

But the P-47D-27 (who's roll characterisitics were close to that of the P-47D-25) PEAKED at the same RATE as the C-1 (to D-23), but at a HIGHER SPEED. And that corresponds to the chart I posted.


In short, Hoar, you are comparing apples to oranges.

Fine, compare the roll of the P-47D-10 and D-22 in FB to that roll chart. You will STILL find FB very lacking in that regard.

But the D-27 in FB should roll in accordance to the chart I posted. Not the one in that report.





Regards,

SkyChimp

http://members.cox.net/rowlandparks/SkyChimp2.jpg



Message Edited on 08/14/0305:12AM by SkyChimp

XyZspineZyX
08-14-2003, 02:17 AM
Thanks Tom. I've seen that before. I think you posted it some time ago.

Era test data show a higher peak roll rate for the P-47D-25. But even the figures in your post are better than what is in FB.

I don't know much about that test in your post. But I would bet that warbird owners were a little reluctant to push their planes to the limits.

Regards,

SkyChimp

http://members.cox.net/rowlandparks/SkyChimp2.jpg

XyZspineZyX
08-14-2003, 02:31 AM
One of the Philadelphia lawyers that I worked for awhile ago owned a F-9 Panther and was a member of the SETP.

Their website is here:

http://www.setp.org/

He let me log on once and I got a paper called "Settling the argument" - It's still available there.

Title (click for abstract) Author(s) Year Aircraft Paper No.

Flight Test Comparison - "Ending The Argument" John M. Ellis and Christopher A. Wheal 1989 P-40 Thunderbolt, FG-1D Corsair, F6F-5 Hellcat, P-51D Mustang 1735

-Tom





<img src=http://a0.cpimg.com/image/68/87/21986920-f885-016800F6-.jpg>

XyZspineZyX
08-14-2003, 02:37 AM
http://members.cox.net/rowlandparks/50lb_roll_2.JPG



The blue line on this graph corresonds to the graph in the NACA report Hoarmuth refers to. The blue line shows the roll performance of a P-47C-1 with a 50 lbs stick force. The P-47D-10 and P-47D-22 should roll in a manner consistent with this line.


The orginal chart shows how a P-47D-30 DID roll with a 30 lb stick force. The red line indicates how it should roll with a 50 lb stick force.


The P-47D-10, D-22, and D-27 in FB should all have roughly the same peak roll rate, but the D-27 will peak at a higher speed than the D-10 and D-22.


No P-47D in FB corresponds even remotely to this chart EXCEPT at very low speed. But even that is off some.

Regards,

SkyChimp

http://members.cox.net/rowlandparks/SkyChimp2.jpg



Message Edited on 08/14/0305:39AM by SkyChimp

XyZspineZyX
08-14-2003, 03:33 AM
SeaFireLIV wrote:
- What the? A petition to just change the P-47? Isn`t
- that just incredibly selfish? What about the rest of
- the sim? Why not play it for at least ONE week first
- before all this Holier than thou other planes
- rubbish?
-
- I hate to think what would happen if Olegg did
- listen to JUST you guys...
- We might as well call the simulation (made by you
- guys)` P-47 and All Else Don`t Matter!`
-
-
-


This is getting very old, your insistance that it has to be played for at least a week is rediculous, What we are talking about can be tested in 15 minutes, many of us did this because this was one of the problems we wanted fixed, so go test it yourself, spawn at 10,000 meters, cruise up to 500 kph, now get your watch ready and roll, it takes 10 seconds to roll a full 360' that is twice what it should be, it won't suddenly get better in a week, and no matter how much I fly, I will never feel it's correct, so STFU and stay out of our thread.
You gone into every thread here spouting this crap, just because you need a week to notice problems doesn't mean we should all be that slow.

<center>http://www.goobage.com/pics/D_Rat.gif </center>
<center><font><font size=1 ><font color=000000>Visit RatFinks Screaming Pile of Sin and Confusion</font></font size> (http://www.goobage.com/forum.php)</center>

XyZspineZyX
08-14-2003, 04:31 AM
Here's the "FB" test mentioned above....I've posted a bunch of other places and encourage people to check my data...

http://users.adelphia.net/~machineii/P-47%20Data.pdf

Interestingly enough for all those "stick force" types, the forces applied in FB appear to actually be HIGHER at 150mph than 50lbs.

Regardless, it's wrong...the curves don't even match the actual performance despite the performance inadequacies.

Also, nobody here is arguing that the P-47 out-roll a Fw190, but that the P-47 in the game bears little resemblance to the one in real life. That's it. In real life the P-47 was a successful fighter which was only supplanted by the P-51 for its longer range...NOT inadequate combat performance.





<html> <body><p align="center">http://users.adelphia.net/~machineii/images/sig3.jpg
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<center><font color=yellow>BlitzPigMachine<font>

XyZspineZyX
08-14-2003, 05:06 PM
Skychimp,


What variants of the P47 reached the USSR via lend-lease?
Is it perhaps possible that Oleg & company are confining themselves to Soviet archival data from tests of those P47's alone?


Blutarski

XyZspineZyX
08-14-2003, 05:28 PM
Also it is people like SkyChimp and Machine (+ all others) who contribute data to make this game what it is. Without their dedication in getting things right you lot would be happy for certain aircraft to remain wrong.

I for one love this game that Oleg has brought us and the fact that a few people offer oleg the correct information shows us not as whiners but as people who are full of praise for Oleg bringing us a combat flight sim of this quality.

There words help him to drive his product to the top of the ratings!

I for one read these posts and salute the chaps who study the data and pass it onto Oleg. For me it means a better more realistic game.

Case closed

http://af-helos.freewebspace.com/BP_Ham%20Sig.gif



Per Ardua Ad Astra

XyZspineZyX
08-14-2003, 05:43 PM
SkyChimp wrote:
-- That is NOT a correct statement.. The relationship
-- between the stick force and the roll rate at various
-- speeds will NOT follow the assumptions you made..
-
-
- It is absolutely correct. It has to, jtasker.

With respect, SkyChimp, you posted about 3 posts above
this one that actual test data was better than calculated.
In extrapolating those lines, you are not using actual
test data at 50lbs stick force.

XyZspineZyX
08-14-2003, 05:47 PM
Maybe you guys should contact Neal Melton out of the Tennessee Aviation Museum who has a real P-47D which may produce real numbers, and see what he gets out of the thing. It was cool to see it flying this weekend btw.

XyZspineZyX
08-14-2003, 05:54 PM
SkyChimp wrote:

- The P-47C-1 to P-47D-23 all had approximately the
- same roll rates at the same speeds. Their roll
- charts would look almost identical.
-
- But the P-47D-27 (who's roll characterisitics were
- close to that of the P-47D-25) PEAKED at the same
- RATE as the C-1 (to D-23), but at a HIGHER SPEED.
- And that corresponds to the chart I posted.

Chimp, are the roll rates in FB for the D10 (since
you say the D10 rates are close to those of the P-47C-1)
correct. If not, then I think it is worth examining
page 166 of that Naca document and comparing them to
FB.

At least give credit to the original poster for not
talking rubbish, but actually having a decent data
source with 50lb stick forces. In the absence of
any other information regarding 50lb stick forces,
it is worth looking at to see how the D10 in FB relates
to this document.




Message Edited on 08/14/0305:04PM by AaronGT

XyZspineZyX
08-14-2003, 06:38 PM
here here Hamish..I whole heartedly agree with u.

BM357_Raven
08-14-2003, 06:50 PM
A very interesting post on the P-47/P-51/F6F comparison... I really enjoyed it.

A small note about the P-51 not giving any stall warning what-so-ever. I am an avid reader of WWII books, and in my readings, on several occasions reading about P-51 pilots I remember reading about buffeting when approaching stalls. The pilots mention feeling this.. Ok, this took me a while to find, but here is an excerpt from Lt. Gen., USAF (Ret.) George Loving, who flew various planes during the war including the P-51B which he flew here:

"...I continued a left break for 180 degrees of turn and was totally surprised to find that two Me-109's had turned with us. I reefed it in tighter, feeling as I did the start of a grayout, and the beginning of a buffet that signaled an approaching stall...."

Now I don't know how incongruent this escerpt is with the type of study mentioned above. Probably a lot. And I know there is a BIG difference between the two P-51 variants, but I thought to submit that I do know that some pilots we better attuned to the warning signs than others. The same could be the case in the studies. Also, if buffeting is more extreme in one type of plane than the other, it might result in a test pilot's failure to notice the charactaritics of a stall coming on, especially if tested by the same pilot within a similar time frame. For a guy who really knows his plane, he can probably sense a lot more...I believe..


And here I am alluding to a certain subjectivity that 'some' of these studies probably include and/or questioning potential differences that could be relavent in the studies between several P-47's of the same model-- that might give a different end-result. I am posing this statement for the sake of the argument that studies 'might' require testing in several of the same planes to get more accurate data. Yes?

Perhaps this is rather academic and without researching the history of the data collection I simply offer the humble question:

Is a given, that the same data will always be obtained by each and every (for example) P-47 ever made, of a certain variant OR can their be gross differences between two planes, of the same make, model, load-out etc? This is a question that I would find interesting to see answered by Sky Chimp in particular. Thank you. http://ubbxforums.ubi.com/infopop/emoticons/icon_smile.gif

BM357_Raven
08-14-2003, 07:01 PM
One other thing came to mind.. In another book, by 'Bud' Fortier, he mentions how the P-40 felt like an absolute lead weight to fly. It was difficult to maneuver on the ground and had a very heavy feel. Power, I suspect was one reason he felt that way...

When he flew the P-47, he mentioned that the P-47 actually felt a lot lighter than the P-40 and that (I think if I understood correctly) as the power came on with the P-47, it really lightened up and began to feel like a fighter.

To me, the P-40 still feels much more nimble than the P-47, which is what I would have expected before reading "An Ace of the Eighth."

Comments or Data to support?
-----------
One thing I CAN say on a purely subjective level is that the P-47 is perhaps (in it's current FM) one of the most exciting planes to fly. Without commenting on FM accuracy, this plane takes a steady hand to control and I equate it with a "real man's" plane..lol (yes I know women jockied them around too during the war--tough gals!)..

The P-40 is another fun plane to fly, imo.. I get bored with planes that seem too perfect, although, in a five minute flight in the Yak-3, I was surprised to find that it felt a little more interesting than it used to.. two cents... /i/smilies/16x16_smiley-happy.gif -- sorry about my 'off-topicness' /i/smilies/16x16_smiley-wink.gif

http://bm357.com/bm357_logok.jpg

XyZspineZyX
08-14-2003, 07:37 PM
Hey all, I'm very surprised that no one has mentioned elevator effectiveness at high speed. I did some diving tests and found that the P-47 looses it elevator over 400-450kph IAS in a dive, similar to the 190 elevator in v1.0.

The '44 dora I was compareing it to had elevator authority all the way up to 650 IAS, enough to get at least a partial blackout. I tested both a/c in a split-s from 7500 meters. Historically, the Jugs elevators were every bit as light, or lighter then the 190s at high speeds (over something like 400mph?).

I also noticed this when going against a Bf-110, I chased it in a dive and when it pulled out I was unable to follow do to lack of elevator authority. This was at under 3000 meters. Historically, the 110 had rather stiff controls, even at moderate speeds.

Has anyone else noticed/tested this or is it just me?

XyZspineZyX
08-14-2003, 08:03 PM
Salute all

Here is a copy of a letter I sent to Oleg prior to the patch and which contains some suggestions. His response was that the rollrate was incorrect and that he would fix it, but that the other issues he disagreed with.

>>>>>>>
Hello Oleg

There are a number of issues which I am hoping you will check as far as the P-47's Flight model is concerned.

The issues I would like to bring to your attention are:

1) I understand you will be correcting the P-47's roll rate. Thank you for making this change. While you are making your corrections, I would ask you to examine the response of the P-47's ailerons at high speed. If you look at this chart:

http://naca.larc.nasa.gov/reports/1947/naca-report-868/index.cgi?page42.gif


You will notice the roll rate remains quite high even at elevated speeds, and does not decrease at a constant rate with an increase in speed. I hope you will consider this in your changed model.

2) The P-47D27 seems to run out of fuel very quickly. With a quarter tank, the aircraft can only fly for about 15 minutes. It seems to run out of gas at about the same as a 109. If so, this is not correct, as the plane had an internal fuel load of 372 U.S. gallons, (1302 litres) which gave it a range on internal fuel of 1020 miles, (1632 km's) which is more than twice that of a 109. The other P-47's do not seem as bad, but they do not seem to have as good a range as they should have. (D-10 had a range of 835 miles) I would appreciate if you could check the fuel consumption rate on these aircraft.

3) The P-47D-10 and P-47D22 seem to have their Revi gunsight mounted too low. This results in the aircraft having a very poor view, partially obstructed by the window frame, and makes deflection gunnery very difficult. If you look at the photographs here:

http://www.web-birds.com/9th/404/halbw3.jpg
here:http://www.web-birds.com/9th/404/halbw2.jpg
here:http://www.web-birds.com/9th/404/mccolpin.jpg


and here:

http://www.billybishop.net/images/rsjhnson.jpg


you will see that in real aircraft the gunsight is mounted much higher than the one in the game in the cockpit view. And it has a clear view over the window frame. The gunsight shown in the photographs is at the 2/3 point of the main cockpit vertical bar area, but the one in the game is much lower. Even external views of the P-47D-10 and D-22 in the game show the Revi gunsight mounted higher as it was historically. I have attached one graphic of this. I think the problem may be in the original modelling of the aircraft cockpit, which has much smaller front windows than historical photographs show and which has confused the issue. That obviously was not your responsibility. However, I am hoping you can adjust the gunsight.

4) I hope you will re-examine the turn rate of the P-47. I realize the aircraft had high wingloading, but when compared to German aircraft such as the Focke Wulf 190, it was actually better, and when compared to the later model 109's, it was not that much different. I have included some data and comments below, which I hope you will consider. I have attached an original USAAF document for weight references.

The model I am presenting here is the P-47D-10. Later models weighed more, but much of that extra weight came from the extra 67 gallons of fuel added in these models.

P-47 D-10 fully loaded: 13, 677 lbs. Of that, 1730 lbs is fuel. 205 US gallons (each gallon is 3.5 litres) in the main tank, 100 US gallons in the auxiliary tank. This weight includes 8 .50 calibre gun installation, and the full 3400 rounds of ammunition.

Normal Combat: 13,077 lbs

With 200 gallon belly tank: 15,000 lbs

Wingloading

Fully loaded: 45.59 lbs per Sq/ft

Normal Combat Weight: 43.59 lbs per Sq/ft (The was a United States Air Force term, and was the weight at which the aircraft was expected to fight at. Normal combat weight is with the Auxiliary tank empty)

Engine: Pratt and Whitney R 2800-63

Maximum 2300 hp at 2700 rpm from Sea Level to 27,000 ft

Military Power 2000 hp at 2700 rpm from Sea Level to 25,000 ft

Maximum Continuous 1625 hp at 2550 rpm from Sea Level to 29,000 ft

Powerloading

Fully loaded: 5.95 lbs per hp up to 27,000 ft

Combat Weight: 5.68 lbs per hp up to 27,000 ft


Some comparison with German aircraft:

Messerschmidt Bf109G6 Data is from Finnish manual for G6 available at:

http://icebreakers.compart.fi//WW2History.html ( <a href=)" target=_blank>http://icebreakers.compart.fi//WW2History.html</a>" target=_blank>http://icebreakers.compart.fi//WW2History.html</a>

Weight Fully loaded: 3500 kgs, 7700 lbs (this is likely a little high, so I will use figure of 3150 kgs or 6930 lbs for my wingloading and powerloading calculations)

Wing Area: 172.75 Sq/ft

Wingloading: 40.11 lbs per Sq/ft

Engine: Daimler Benz DB605A

Rated at 1475hp at Sea Level

Rated at 1355hp at 5,700 metres

At higher altitudes, the maximum engine power dropped off considerably, to the area of 1,025 hp max.

Maximum continuous power at sea level, 1080 hp

Powerloading:

4.69 lbs per hp at Sea Level Maximum power

5.11 lbs per hp at 5700 metres Maximum power

Approx. 6.76 lbs per hp at 9000 metres.


Focke-Wulf 190A8 (Data from "Focke Wulf FW190 by Gordon Swanborough and William Green")

Empty Weight: 7652 lbs

Normal Loaded weight: 9660 lbs

Wing Area: 196.98 Sq/ft

Wingloading: 49 lbs per Sq/ft


Engine: BMW 801D

1700 hp at Sea level

1,440 hp at 18,700 ft

Powerloading

5.68 lbs per hp at Sea Level

6.7 lbs per hp at 18,700 ft


The powerloading of the P-47 would suggest that it would not be very good at low altitudes, but would eventually gain the advantage on both the 109 and 190 at higher altitudes.

The wingloading of the P-47 is actually superiour to the FW190A8, and is not that much different from the 109G6.

Now I realize that a larger heavier aircraft, will require a larger force exerted on it to change direction than a smaller lighter aircraft. Even if it has the same wingloading.

For that reason, the logic of a 6930 lb Bf109 being able to turn more quickly than a 13,500 lb P-47 is obvious.

At low speeds, this is certainly the case. A P-47 without a speed advantage should not be able to outturn a 109 at lower speeds. Especially at lower altitudes, when the 109 has better powerloading.

Plus the drag of the P-47's larger airframe would cause more speed bleed.

However, at high speeds, when the effects of airflow over the control surfaces reduce their effectiveness, these arguments only apply if the forces which can be applied to change the aircraft's direction are proportionately equal.

At higher speeds, the P-47 would not have the same problems as it would at low speed with the onset of a stall in a high G turn. At higher speeds a pilot would be able to pull higher G turns before approaching the point of an accelerated stall.

The P-47 also had all metal coverings on its control surfaces, ie. ailerons, elevators and rudder. This was an advantage over aircraft with fabric covered control surfaces, which were subject to distortion at high speeds, ballooning etc. The P-47 did not have this problem at high speeds.

The book "America's Hundred Thousand" says that the aircraft had very light controls at most speeds, in fact the stick forces became lighter at higher speeds. According to this source, a modern evaluation gave a stick force of 7.5 lbs per G.

The P-47 had modifications to the elevator controls which designed to give better response at high speeds.

The first P-47C (41-6066) was completed on September 14, 1942. Even though the
P-47C incorporated strengthened tail surfaces, the P-47C still had some problems in
recovering from the very high dive acceleration and terminal speeds which could be achieved with the P-47. The aircraft was rated capable of diving safely to 500 mph, (800kph) safely. However because the aircraft accelerated so fast, it could reach speeds beyond 500 mph. Beyond that speed, recovery from power dives was hazardous, with the elevators being unable to respond because of compressibility forces.

(note: Many German or Soviet Fighter aircraft could not even reach 500mph without disintegrating. The fact that the P-47 was able to maneuver up to 500mph is indicative of its excellent high speed characteristics even in the early P-47C model)

The engineers at Republic took a number of steps to improve the aircraft's ability to respond at high speeds.

The P-47C-1-RE production block differed by having an extra 8-inch section added
to the fuselage forward of the firewall to change the center of gravity and giving improved flight characteristics.

Additionally, Bob weights or counterbalance weights were installed in the elevator control system, to help to overcome the compressibility problems that had made high speed dives in the earlier P-47C dangerous.

These bob weights allowed additional leverage to be applied to the P-47's elevators, leverage which was enough to move them, at 500mph or higher despite compressibility effects.

The P-47, like the FW190 also had its aileron, elevator and rudder surfaces moved by control rods, not wire cables. These allowed more leverage to be applied and were no subject to stretching.

On November 13, 1942, Test Pilots Lts. Harold Comstock and Roger Dyar managed to reach airspeeds of 725 mph during high-speed dives in their later model P-47Cs. This was beyond the speed of sound, which, if accurate, would have made them the first pilots to break the sound barrier. However, it is likely that the airspeed
readings were inaccurate, since the terminal velocity of the P-47 is
about 600 mph. Still it is clear they reached the 600mph range. (960 kph)

The fact that they were able to reach these very high speeds, and recover safely from them, shows the effectiveness of the Elevators on the modified P-47C-1RE.

In some cases P-47's would enter compressibility at high altitudes in an extreme high speed dive, but would always recover elevator control when more dense air at lower altitudes was encountered.

The fact that the P-47 had good response from its elevators, is in direct contrast to aircraft such as the Bf109, which had very poor high speed elevator response.

The later model P-47's were rated as capable of diving up to 550 mph.

Various tests of different models of the 109 tested showed poor response at high speeds.

Following is an excerpt from a British AIR FIGHTING DEVELOPMENT UNIT test of a 109E3 for which I have the original document scan, and which I can send you if nessesary. It deals with control response.

>>>>>>>>>>

"Ailerons
At low speeds the aileron control is very good, there being a definite resistance to stick movement, while response is brisk. As speed is increased, the ailerons become heavier, but response remains excellent. They are at their best between 150 mph and 200 mph, one pilot describing them as an 'ideal control' over this range. Above 200 mph they start becoming unpleasantly heavy, and between 300 mph and 400 mph are termed 'solid' by the test pilots. A pilot exerting all his strength cannot apply more than one-fifth aileron at 400 mph. Measurements of stick-top force when the pilot applied about one-fifth aileron in half a second and then held the ailerons steady, together with the corresponding time to 45 degrees bank, were made at various speeds. The results at 400 mph are given below:
Max sideways force a pilot can apply conveniently to the Bf.109 stick 40 lbs.

Corresponding stick displacement 1/5th.
Time to 45-degree bank 4 seconds.
Deduced balance factor Kb2 - 0.145

Several points of interest emerge from these tests:
a. Owing to the cramped Bf.109 cockpit, a pilot can only apply about 40 lb sideway force on the stick, as against 60 lb or more possible if he had more room.
b. The designer has also penalized himself by the unusually small stick-top travel of four inches, giving a poor mechanical advantage between pilot and aileron.
c. The time to 45-degree bank of four seconds at 400 mph, which is quite escessive for a fighter, classes the airplane immediately as very unmaneuvrable in roll at high speeds.
Elevator
This is an exceptionally good control at low air speeds, being fairly heavy and not over-sensitive. Above 250 mph, however, it becomes too heavy, so that maneuvrability is seriously restricted. When diving at 400 mph a pilot, pulling very hard, cannot put on enough 'g' to black himself out; stick force -'g' probably esceeds 20 lb/g in the dive."

<<<<<<<<<<<

It is true that later models of the 109 were improved, most notably with the re-design of the 109F, but the problems continued. Following is an excerpt from an AFDU test of a 109G6 which confirms this problem existed with later model 109's. There was a basic lack of leverage, which limited control surface movement.

>>>>>>>>>>>

"The ailerons became increasingly stiff as speed was increased and were especially so at speeds in excess of 350mph. The Elevators became increasingly difficult to operate as speed increased, and above 350mph this unpleasantness was accentuated as the elevator trim was practically impossible to operate."

<<<<<<<<<<<

The Finnish Air Force Handbook which I have referred to earlier on their late model 109G6 also shows that the elevator response of these planes went down considerably at higher speeds.

Turning time for the aircraft was stated as follows in the manual:

At 400 kph turn time was 13 seconds for a 180 degree turn.

At 450 kph turn time was 14 seconds for a 100 degree turn.

This shows that with only a 50 kph increase in speed, the turn time became much worse, and indicates the elevator response was decreasing quickly.

The Finns also listed a maximum dive speed of 750 kph for the late model 109G6. That is only 468 mph and indicates the chances of recovery with the aircraft decreased considerably at higher speeds.

According to a recent interview with Franz Stigler, a Luftwaffe pilot who had over 400 sorties in 109's, the G6's handling at higher speeds was not good.

http://icebreakers.compart.fi//WW2History.html

He was asked a direct question about dive speeds:

What's the fastest you ever had a 109 in a dive?

I've taken it to about 680 to 750 km/hr at which point you needed 2 hands to pulls it out of the dive.

Pilots who exceeded the reccommended dive speed had extreme difficulty in recovering:

Finnish Pilot Jussi Huotari from recent interview

http://icebreakers.compart.fi//WW2History.html

I lost my speed, I had to turn below them. I had to push the stick to get behind them, and as they dived at me I dived right down. I turned with ailerons a couple of times, and had full power on.
Then I started recovery from the dive, of course in the direction of home, then checked the dials, the reading was eight hundred plus kmh. Then I started pulling the stick, pulled harder as hard as ever: never in my life did I pull so hard. I pulled with right hand and tried to trim the horizontal rudder with my left hand. But it did not budge, as if it had been set in concrete. But by the by the nose began to rise, but terribly slowly. As my angle was about 45 I heard over the radio as Onni Paronen said, "hey lads, look, a Messerschmitt is going in the sea!" I wanted to answer back but I could not afford to do anything put pull with two hands. As soon as I had returned to level flight and had been able to breath normally for a while, I in a way regained consciousness. I pushed the transmitter key and said "not quite". It was a close shave.

(in all these accounts it is likely that the actual speeds in the dives were slower than the pitot tubes were indicating. Most of the time such instruments exagerrated as was the case with the P-47 test dives)

<<<<<<<<<<<

The later mode P-47 from the C-1RE onwards suffered from no such problems at high speeds.

It had an official maximum allowable dive speed of 550mph IAS (880 kph) below 10,000 ft listed in its manual.

With the advent of the bubble top P-47, and its higher horsepower engine, dive acceleration increased again. Again a redesign with the addition of dive recovery flaps allowed for recovery from even very high speed dives in these models.

How does the P-47 compare to the FW190?

Comparisons of wingloading show that the P-47 had either comparable or better wingloading than the FW190's of its era.

The FW190 did have better lateral high speed maneuverability than the Bf109. Reports show that its aileron effectiveness remained good even at higher speeds, although it declined from its best speed range of 250mph. The 190 had the best rollrate of any WWII era aircraft at low and medium speeds, but was matched by the P-47 and P-51 at very high speeds. (see the chart I have listed earlier)

Elevator effectiveness on the 190 was also quite good, although not as good at high speeds. In fact a USAAF test of a 190A5 versus a P-47D4 with fuel injection showed that the P-47 had the advantage at speeds over 250mph, although at low speeds, where the 190's elevators remained fully effective, that it was capable of outturning the P-47.

A test was conducted between a 190A5 and a P-47D4 with Water injection in December 1943. The 190 was in excellent condition. Following is an excerpt of the document of which I have a scan of the original if you wish to examine it.

>>>>>>>>>

3) Turning

a) Turning and handling in excess of 250mph. The two airplanes alternately turned on each other's tail, holding in the turns as tightly as possible and alternating the turns first left then right. The P-47 easily out-turned the FW190 at 10,000 ft and had to throttle back in order to keep from overrunning the FW190. The superiority of the P-47 in turning increased with altitude. The FW190 was very heavy in fore and aft control, vibrated excessively and tended to black out the pilot.
b) Turning and handling below 250mph. Turns were made so rapidly that it was impossible for the airplanes to accelerate. In making the usual rather flat turns in a horizontal plane, the FW190 was able to hang on its propellor and turn inside the P-47.

<<<<<<<<<<<

What these comparisons between the P-47, the 109 and the 190 show, is that the P-47, while inferior at low speeds, had distinct advantages in high speed maneuver, something which particularly suited it for combat at high altitudes or in maneuver which occurred in high speed dives from altitude.

4) A final issue which I hope you will look at is the damage model for the P-47. I find from experience, that the aircraft is very often seriously damaged by the fire of single light 7.92mm machine guns from bombers and attack aircraft. This very often results in a destroyed engine, or severed control cables. From my own readings of pilot accounts, and my own examination of a real Pratt and Whitney R-2800 in an air museum, it is highly unlikely that a rifle calibre bullet would be able to destroy such an engine. In regards to the control mechanisms for elevators, ailerons and rudders, as I have mentioned before, the P-47 had no cables, but used a system of metal rods, which were much heavier than simple cables found on other aircraft. The FW190 also had this system. These rods would not be easily damaged by a rifle calibre bullet. There were also redundant systems, that is, there were separate rods for each wing aileron. There is finally the question of damage to the turbo charger system from a bullet entering the inlet or outlet channels. From my examination of these diagrams:http://rwebs.net/avhistory/images/superchg.jpg
it would not seem likely that a bullet would have an unobstructed path into the turbocharger, but would hit sheet metal or exhaust pipes first.

I hope you will consider all these comments.

Once again, I would like to thank you Oleg for your patience in listening to your customers and loyal fans. Good luck in your patch and good luck in all your other projects!

Thankyou RAF74 Buzzsaw

XyZspineZyX
08-14-2003, 09:46 PM
-MachineII wrote:
- In real life the P-47 was a successful fighter which
- was only supplanted by the P-51 for its longer
- range...NOT inadequate combat performance.
-

That was part of the reason. The Mustang was a cheaper aircraft ($50K versus $85K for the P-47), and we all know that the US, even during WWII, tended to still appreciate a better bargain that allowed for greater mass (though the P-47 still managed to beat out all other US fighters in terms of number produced during the war, mainly due to its earlier service entry date). And unlike the P-51 with its inline Merlin, there were a lot of other competing requirements for those big radial engines in the US aviation production arena (not to mention the use of radial engines to power M4 Sherman tanks).

BTW I believe the P-47N had a greater range than any of the Mustang variants...

-Tom
(who likes Jugs... so to speak ;-P )

<img src=http://a0.cpimg.com/image/68/87/21986920-f885-016800F6-.jpg>

Message Edited on 08/14/0304:57PM by Tommel6

XyZspineZyX
08-14-2003, 09:51 PM
RAF74BuzzsawXO wrote:
- Salute all
-
- Here is a copy of a letter I sent to Oleg prior to
- the patch and which contains some suggestions. His
- response was that the rollrate was incorrect and
- that he would fix it, but that the other issues he
- disagreed with.
-
-

(snip to save space)

Very nice - I'm curious to how Oleg will respond to that.

-Tom


<img src=http://a0.cpimg.com/image/68/87/21986920-f885-016800F6-.jpg>

XyZspineZyX
08-14-2003, 10:17 PM
Hoarmurath wrote:
Finnish Pilot Jussi Huotari from recent interview
"...but by then the nose began to rise, but terribly slowly. As my angle was about 45 I heard over the radio as Onni Paronen said, "hey lads, look, a Messerschmitt is going in the sea!" I wanted to answer back but I could not afford to do anything but pull with two hands."


Sorry man.
I hope you guys get the correct roll rate for the P-47.
I just though this was cartoon-like funny /i/smilies/16x16_smiley-very-happy.gif /i/smilies/16x16_smiley-very-happy.gif /i/smilies/16x16_smiley-very-happy.gif /i/smilies/16x16_smiley-very-happy.gif

<center>http://users.compulink.gr/ilusin@e-free.gr/bf109[2)1.jpg

XyZspineZyX
08-15-2003, 01:45 AM
Bump