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View Full Version : I'm missing compressibility on these planes:



KaRaYa-X
08-24-2004, 07:59 AM
Fighters which should show compressibility effects but don't as of now:

-P51B
-P51C
-P51D5/20
-all P47s... however we would need dive recovery flaps for the P47D27 which was the first Thunderbolt that got 'em
-FW190A
-FW190D
-Ta152
-maybe a bit more compressibility on the Spitfires
-Ki84 all versions


I don't want to say that these planes should be stiff like concrete at high speeds - but the way it is right now can't be realistic. Especially the Mustangs could need "some" stiffening (at least to please the my-stang-looses-a-wing-at-800km/h-IAS-when-pulling-back crowd) and the P47 even more.
I've frequently come across articles on the internet and the "Flight-Journal" magazine that suggested that up to the P47D27 (which finally had dive recovery flaps) pilots constantly had to be careful not to overdive the T-Bolt into compressibility (similar to the P38!).

As to the credibility of the articles from "Flight-Journal" Magazine: The author was Corky Meyer - a rather famous test pilot who test-flew about every important fighter of WWII (among them the Bf109, Spitfire, Airacobra, Kingcobra, Thunderbolt, Mustang, etc. - all in different versions - but unfortunaltely he did not have the chance of getting his hands on a FW190)


So, pls let me know what you think of it

--= flying online as JG52<Karaya-X =--

KaRaYa-X
08-24-2004, 07:59 AM
Fighters which should show compressibility effects but don't as of now:

-P51B
-P51C
-P51D5/20
-all P47s... however we would need dive recovery flaps for the P47D27 which was the first Thunderbolt that got 'em
-FW190A
-FW190D
-Ta152
-maybe a bit more compressibility on the Spitfires
-Ki84 all versions


I don't want to say that these planes should be stiff like concrete at high speeds - but the way it is right now can't be realistic. Especially the Mustangs could need "some" stiffening (at least to please the my-stang-looses-a-wing-at-800km/h-IAS-when-pulling-back crowd) and the P47 even more.
I've frequently come across articles on the internet and the "Flight-Journal" magazine that suggested that up to the P47D27 (which finally had dive recovery flaps) pilots constantly had to be careful not to overdive the T-Bolt into compressibility (similar to the P38!).

As to the credibility of the articles from "Flight-Journal" Magazine: The author was Corky Meyer - a rather famous test pilot who test-flew about every important fighter of WWII (among them the Bf109, Spitfire, Airacobra, Kingcobra, Thunderbolt, Mustang, etc. - all in different versions - but unfortunaltely he did not have the chance of getting his hands on a FW190)


So, pls let me know what you think of it

--= flying online as JG52&lt;Karaya-X =--

VMF513_Sandman
08-24-2004, 08:03 AM
in the words of oleg: bring proof..documented proof. he obviously dis-credits practically all pilot accounts. he didnt even give any 'credibility' to spec's direct from lockheed on the 38's.

p1ngu666
08-24-2004, 08:09 AM
i thought the spits got abit too stiff, but there we go http://ubbxforums.ubi.com/images/smiley/16x16_smiley-wink.gif

the snapping wings, from my limited testing is from how fast u move the stick, not nessoerly the deflection. im not sure but i only think it effects the p51's and go229

http://www.pingu666.modded.me.uk/mysig3.jpg
&lt;123_GWood_JG123&gt; NO SPAM!

KaRaYa-X
08-24-2004, 09:13 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by p1ngu666:
the snapping wings, from my limited testing is from how fast u move the stick, not nessoerly the deflection. im not sure but i only think it effects the p51's and go229
<HR></BLOCKQUOTE>

Yes that's right but actually this happens on a lot of birds (including the Ki84, all FW190s, the P51, all jets, the Me163) - but my major concern wasn't wing-snapping...

--= flying online as JG52&lt;Karaya-X =--

Fennec_P
08-24-2004, 10:25 AM
Control heaviness seems to be a very elusive factor in this game.

Most of the planes, epsecially the ones from the original IL-2, have had their control responsiveness changed many times.

The FW-190 used to have a brick elevator until FB, where it was made the exact opposite. The La-5 and La-7 was light in IL-2, then it was changed to heavy, now it is lighter than before. The MiG-3 used to have relatively good controls, and now it locks up at anything above 400km/h.

Not to mention the P-47, Spitfire and others that have changed within the last few patches, though not as much.

The fact that it oftens changes back and forth seemingly at random suggests that there is no hard data for any of this. If there were, the control responsiveness would be set to a specific value and left there.

More likely, they are using pilot accounts, or subjective info from tests. Every time they get new info, they change it.

Willey
08-24-2004, 01:24 PM
Compression is not modelled at all in FB.

And rudder forces aren't that realistic.

Some weeks ago I read a quote from one 109 pilot on the german board. Forgot who he was, I think it was Grislawski.
He said that he could pull 6 G in a 109G at some 850 IAS. I tried that in FB with neutral trim and UDPSpeed and got nice 10 G. Now, even this concrete elevator is overmodelled. Now that tells me, that all others must be much more uber. Remember Eric Brown and his stick settings? There you have it.

WWMaxGunz
08-24-2004, 04:45 PM
It may be that pilot strength modelled may be changing.
Perhaps able to use both arms now.


Neal

TooCool_12f
08-25-2004, 01:20 AM
10G at 850kph IAS? how did you do that? my 109 just goes straight at such speeds http://ubbxforums.ubi.com/infopop/emoticons/icon_wink.gif

polkku
08-25-2004, 01:41 AM
You can use combat flaps in any speed without damage. I tested them with many planes e.g. Lagg3 (the old one), P-51D, P-38J, FW-190, LA-5...etc and the wings fell off, but combat flaps worked fine at maximum speeds. That's how you can get some more G's to your turns.

Ugly_Kid
08-25-2004, 02:13 AM
I think Willey made a typo...I can't pull black-out with neutral trim with 850 IAS on Bf (BO onset is about 6 g)

http://people.freenet.de/hausberg/oksennus_1.jpg

VMF513_Sandman
08-25-2004, 06:22 AM
used to be, the jug would outdive anything short of a jet. now it seems that at or about 850, the jug starts shedding. maybe at extreme speeds do the jugs' start to get into compressability...but still at a much higher speed than either of the 38's; J's being the most unforgiving model dive-speed wise.
i was taken a bit on how the p-51 would snap wings, and yea, it is true on how fast u try to recover from a dive. zeno's warbirds had a clip of a pilot going into a full power dive, but obviously, oleg sez 'that's just propaganda'. overall speed wise, the 51 is a formidable fighter; but like the 38, it has flaws that's certain death to those that know where to hit it.

Willey
08-25-2004, 09:19 AM
OK, I redid the test.

http://home.arcor.de/eldur/bilder/gees.jpg

8,3G, close to the deck, @ 850IAS, Krim QMB default, 5000m, G-6 early, full pull and neutral trim.

The one where I made 10G I was at ~2-3000m or so. Higher TAS. And therefore more G in FB, as the max control plane deflection is defined by TAS. IRL handling and forces depend on IAS.

That's still 2,3G more http://ubbxforums.ubi.com/images/smiley/16x16_smiley-wink.gif

WWMaxGunz
08-25-2004, 09:24 AM
How fast did you get to 8.3G?
Did you use combat flaps?
Nice to know it's possible, now we want the how!


Neal

Willey
08-25-2004, 09:43 AM
No flaps, just pull back. As it takes some time until the blackout effect kicks in, there's no blackout visible. Greyout starts at 3.5 or 4 G IIRC and complete blackout at prolonged 7G.
I got those 8,3 quite quickly... was maybe 1-2 seconds after I started pulling.

p1ngu666
08-25-2004, 10:22 AM
in my very brief flying of late 109's, the g14 is awful elivator, the g10 is WAAAAAAAAAAY better
the thing is, u can very easily move stick quickly to 1/4 or less defelction and THAT pops the wing. iirec most things can survive brief g forces of stupid levels.
eg indycar drivers have susstained 180-200g for VERY short time.

oh it happens to the he162 too aswell, they made the elivator effective in last patch, before it was like a 109

http://www.pingu666.modded.me.uk/mysig3.jpg
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