Best radial fighter of '42

[HoHun]

Hi Vincenzo,

>HoHun can explain me why italian fighter climb speed are so different from italian test?

No idea. At which flying weights were the figures you quoted achieved?

I know that over on Aces High forum, Italian forum member Gatt and Aces High's Hitech discussed climb rate figures for some Italian fighter (of a later generation, I believe) that were too high to be realistic. Gatt had contact to a retired Macchi engineer (I believe - maybe it was an other company), and I seem to remember that after much research, lower figures were accepted as probable.

Maybe this was not type-specific, but systematic for Italian ratings and procedures?

Regards,

Henning (HoHuN)

 

[Elvis]

I'm going with the FW-190.

Thanks for the reminder...I don't think I mentioned this before, so just a word to say I'm changing my vote.
FW-190 for me, too.
I didn't know that the cooling problems were solved, but I guess they were.
That was really the only thing holding me back from voting for it.

...btw, I've never seen shark's teeth on a Spitfire before, Pong.
Interesting picture.




Elvis

 

[Vincenzo]

Hi Vincenzo,

>HoHun can explain me why italian fighter climb speed are so different from italian test?

No idea. At which flying weights were the figures you quoted achieved?

I know that over on Aces High forum, Italian forum member Gatt and Aces High's Hitech discussed climb rate figures for some Italian fighter (of a later generation, I believe) that were too high to be realistic. Gatt had contact to a retired Macchi engineer (I believe - maybe it was an other company), and I seem to remember that after much research, lower figures were accepted as probable.

Maybe this was not type-specific, but systematic for Italian ratings and procedures?

Regards,

Henning (HoHuN)

Hi
Test weight are already give.
can give me the title of topic on Aces High for find it?
I'm not engineer but, at example, power load of macchi it's good, only 6% more of type 1 (and that it's for WEP), also more near to Type 0 (the best climbing in graphs)

 

[HoHun]

Hi Vincenzo,

>can give me the title of topic on Aces High for find it?

I'm afraid you'll have to rely on the search engine since I didn't save that thread

Regards,

Henning (HoHun)

 

[Vincenzo]

Hi
i can't use search engine, almost until they not accept my registration, I hope they accept me in short times

 

[Timppa]

HoHun can explain me why italian fighter climb speed are so different from italian test?
The G. 50 climb at 4 km in 254'' so it's 15,7 m/s average, the max climb in the graphs is ~13,5 m/s

Finnish G.50's could not match the book values (as was the case with almost all fighters used by the FAF, the notable exeptions being the Brewster and the Bf109).

Finnish G.50: Speed 380 km/h OTD, 890 mmHg.
403-430 km/h at 5000m (depending on the propeller), boost 790 mmHg.
Best climb rate 14m/s OTD, reducing linearly to around 10m/s at 4000m.

 

[Vincenzo]

Hi Timppa
i think that plane of suomen test are heavy and w/o closed clockpit, i don't know if weather condition can influence test but maybe.

for true i see on kurfurst site the test of 109 gustav and also this non match con deutsch test

 

[Vincenzo]

To Finnish friends
there is a web page where see (read) the finnish test of old (continous war and or winter war) FAF fighters?

thanks

 

[ssnider]

how about some charts with the brewster variants?

 

[HoHun]

Hi Ssnider,

>how about some charts with the brewster variants?

If you can find good data on weight, top speed at altitude, engine power at various altitudes, reduction gearing and propeller diameter of each version etc., that would increase the chances

Regards,

Henning (HoHun)

 

[Juha]

Hello HoHun
FAF B-239
Wright R-1820-G5, t/o power 950hp at 2200rpm 104cmHg boost pressure at SL
Combat power 1000hp at SL, 800hp at 4900m, max 5min
Nominal 850hp at SL at 2100rpm 93 cmHg, 750hp 2100 rpm 86 cmHg at 4570m. 2-speed supercharger
3 blade Hamilton Standard constant speed airscrew diameter 2,74m blade travel 13-31 deg
T/o speed 120km/h
Best climb speed 220km/h IAS at low level, 180 km/h IAS at 5000m.Change to high gear at 3000m
Climb with nominal power and at 2275kg 6min to 4572m. At 2387kg 6.7 min.
Max speed 428 km/h at SL 480 km/h at 4750m (in fact a bit higher because of ram effect)
Stall speed clean c. 130km/h, with power on c. 120 km/h

HTH
Juha

 

[HoHun]

Hi Juha,

Thanks, that looks like good data! It's not clear what kind of performance was achieved with which level of power, but I think I could make some good guesses on that.

Climb rate was with 2100 rpm "Combat" power I think since if I use this power, I hit the figures almost dead on.

I have used power figures from AEHS Home, which look quite similar but were easier for me to handle.

For the graphs, I decided to use 2200 rpm, 930 HP for low gear maximum power and 2200 rpm, 775 HP for high gear maximum power. This appears to match the enginehistory.com figures.

Regards,

Henning (HoHun)

 

[HoHun]

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[HoHun]

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[Juha]

Thanks a lot, HoHun!!!
When I typed the info, I noticed that there were gaps, for ex the boost pressure of Milit. Power was lacking. BTW, do you have info on the blower gear ratio of R-1820-G5? The Wright engine specs file on AEHS site lacks pages 7 and 8, where –G5 info should have been. A year ago KK89 gave blower gear info for G-1, -2, -3 and -6 but not for -5.

Juha

 

[HoHun]

Hi Juha,

>BTW, do you have info on the blower gear ratio of R-1820-G5? The Wright engine specs file on AEHS site lacks pages 7 and 8, where –G5 info should have been. A year ago KK89 gave blower gear info for G-1, -2, -3 and -6 but not for -5.

It's on their site, but under the confusing title "Model Designations of U.S.A.F Engines":

ModDesig

The R-1820-39 is identified as the -G5, and is listed with a 10.7" diameter supercharger wheel and 7.14 and 10 gear ratios. Compression ratio is 6.45.

Regards,

Henning (HoHun)

 

[Juha]

Thanks a lot, HoHun!

Juha

 

[Juha]

Hello HoHun
Regrettably I must inform that I seem to be suffering a slight reading problem. In my message #211 I wrote that Wright R-1820-G5 had 2-stage supercharger but it had 2-speed supercharger. When I read my source I read kaksivaihteinen as kaksivaiheinen, that's the reason for the mix up. I corrected the error in the original message.

Juha

 

[HoHun]

Hi Juha,

>Regrettably I must inform that I seem to be suffering a slight reading problem. In my message #211 I wrote that Wright R-1820-G5 had 2-stage supercharger but it had 2-speed supercharger. When I read my source I read kaksivaihteinen as kaksivaiheinen, that's the reason for the mix up. I corrected the error in the original message.

Thanks for the heads up! No impact on the calculations fortunately, as the horse power numbers were the decisive bit of information - a single-stage supercharger is not as efficient, but it requires no special treatment during the analysis.

Regards,

Henning (HoHun)

 

[Elvis]

Henning,

I was noticing in the "sustained turn rate" chart, it appears you have the B-239 listed at almost 26 deg/sec at ground level, yet the rate has slowed to approximately 21.25 deg./sec @ 2000M.

I thought that was kind of an odd figure, so I looked back at the http://www.ww2aircraft.net/forum/aviation/p-40-vs-me-109-a-12342-5.html thread, because I remember quite an indepth discussion about turn rates of different airplanes in there.
In post #73, Ju Ha wrote the following as part of that post...

Brewster Model 239
Sustained 180deg at 350kmh (IAS) at 2000m 7sec, no wonder that Finns liked the plane.

That works out to 25.7+ deg./sec.

Why the differences in those figures compared to yours?



Elvis