Bf109G6 climb rate

[III/JG2Gustav05]

Hello Guys,

 

G6 is the backbone of Luftwaffe between 2nd half of 1943 and 1944. I saw some German test reports present 17m/s at sea level with 1.3 ata. why this number is so low? this number is 100% fuel or 50% fuel result? G6 is heavier than G2 only 90kgs. G2's result is about 21m/s with 1.3ata according to German result. G2 with MG151 gunpods still can achieve 5.1 mins to 5km according to VVS test result. this number should approximately match18m/s at sea level. IIRC gunpods add 215kgs to its weight. sure also creates additional drug like the bumps for MG131 on G6.

Figures below are cited from il2 1946,

bf109G6 has 17.7m/s climb speed at SL at 1.3Ata, according to the climb speed vs altitude profile in il2compare, climb to 5km needs 5'15''. this number exactly matches the figure presented in some historical document.

La5Fn has ability >26m/s at sea level. its climb rate is competent to G6 even up to 4km.

I am curious how Luftwaffe pilots managed to survive when they meet L5fn at that time?  

Edited January 8, 2016 by III/JG2Gustav05

[Finkeren]

17 m/s is the figure I've seen quoted as well, but honestly I don't think it fits together with all the other values you cited.

 

Sure enough, the changes made to the G-5/6 degraded performance noticeably across the board, but I seriously doubt, that the RLM would've accepted such a big loss of climb performance.

[III/JG2Gustav05]

According to Kurfurst's site G6 should be heavier than G2 90kgs instead of 150kgs. underwing 2cm MG 151/20 cannons are 215 kg instead of 330kgs I mentioned above. Any wartime pilot account mentioned big performance degraded from G2 to G6?

Edited June 23, 2015 by III/JG2Gustav05

[6./ZG26_5tuka]

Which G-6 are you referring to? The first series had a weaker engine while the later ones with DB605 AS had better performance than the G-2.

 

I can try digging for some german data once back home.

[III/JG2Gustav05]

Which G-6 are you referring to? The first series had a weaker engine while the later ones with DB605 AS had better performance than the G-2.

 

I can try digging for some german data once back home.

Thank you 5tuka, I am interested in both types you mentioned.

[6./ZG26_5tuka]

Here's sth for the G-6 trop with sandfilter

http://www.wwiiaircraftperformance.org/me109/VB-109-10-L-43.pdf

 

http://www.wwiiaircraftperformance.org/me109/me109g-16476.html

 

As for the DB605AS engine I only found data for the G-5 by now

http://www.wwiiaircraftperformance.org/me109/VB-109-20-L-43.pdf

[III/JG2Gustav05]

I found 1 interesting document on website WWIIAIRCFRAFTPERFORMANCE. http://www.wwiiaircraftperformance.org/me109/VB-8-18-205-001.pdf

 

This test was done on a Bf109G6 with DB605AS engine. decreasing the cooler opening about 100mm can increase climb rate more than 1 m/S, climb time to 5km decrease from 5 min to about 4'40'' and increase level speed 25kph but the coolant temperature does not increase. so that means the radiator opening on Gustav is not optimized and manual radiator control can increase the performance noticeably?

Edited December 2, 2015 by III/JG2Gustav05

[III/JG2Gustav05]

Base on the data what I listed above maybe we can give a try to extrapolate G6's reasonable climb data with kampfleistung and auto-radiator in theory.

what we have right now are,

Bf109G6 is heavier than Bf109G2 90kg.

Bf109G6's MG131 bulges decrease 9km/h top speed.http://www.wwiiaircraftperformance.org/me109/me109g-16476-b.html

non-retractable tail wheel decreases 12km/h top speed.

 

Bf109G2 with MG151 gun pods is heavier than standard version 215kg, gunpods creates 12km/h speed lose.http://www.wwiiaircraftperformance.org/me109/VB-109-08-L-43.pdf

 

Accrdingto Rechlin's 1943 report, Bf109G2 with non-retractable tailwheel works at 1.3ata climbs to 5km need 4'11''. http://kurfurst.org/Performance_tests/109G_Rechlinkennblatt/rechlin_G1_blatt.html

 

Bf109G2 with MG151gun pods climbs to 5km needs 5'06'' according to VVS test report. http://www.wwiiaircraftperformance.org/me109/VVS-Me_109_G2.pdf

So comparing with standard Bf109G2 and gun pods Bf109G2 we have 55'' difference which created by the MG151 gunpods' weight and air fraction.

 

How does air fraction impact climb performance? accroding to http://www.wwiiaircr...-18-205-001.pdf  25km/h speed lose by the fraction created by wider flaps opening can increase 20 sec to climb to 5km.

therefore 12kph speed lose created by gun pods could increase 12/25*20 = 9.6sec climbing time to 5km.

then the remaining part of delay is created by gunpods weight (215Kg), which is 55''-9.6''=45.4 sec.

G6's additional 90kg weight should increase 90/215*45.4=19sec climbing time to 5km.

the air fraction created by G6's bulges should increase 9/25*20=7.2 sec climbing time to 5km.

In sum G6 's climb time to 5km at 1.3 ata should be 4'11''+19''+7.2"=4'37''. which contrast to the most popular data 5'15'' instead.

4'37'' is reasonable figure for climb time to 5km with auto radiator setting at 1.3Ata. calculated corresponding climb speed at SL is 19m/s.

Edited January 9, 2016 by III/JG2Gustav05

[6./ZG26_Klaus_Mann]

It's all in the testing process. For the 109s the Radiators have an enormous impact on rate of climb, due to the extreme openings they can achieve, acting almost as airbrakes.

 

Erla did much of their testing with new machines designated to enter combat. So in order to protect the not yet properly run in engines they performed their tests with the thermostat set to roughly 80-90°C, or 50% radiators. This test gives us best rates of climb of 18.5m/s below 2000m

 

In Rechlin they performed a single line of tests for almost closed radiators on a late production G-1. This is the test that resulted in 21m/s. 

 

All other 109s were tested to ERLA Standards, which means that as a Starting point is 18.5m/s, and the increase for closed radiator openings lies right about 13.5%

 

In a compilation  [http://www.kurfurst.org/Performance_tests/109G1-6_datasheet/109G_perftable.html]the G-2 Recce Variant acheived 18.2m/s, which is close to the other ERLA Values and therfore very much usable. 

 

The Bf109G-2 with MG151 Pods achieved 17.1m/s

The Bf109G-6 with MG151 Pods achieved 16.5m/s

The Bf109G-6 with taller tail unit (heavier) did 17.5m/s http://www.kurfurst.org/Performance_tests/109G_Leistungzusammenstellung/Leistungzusammenstellung109G.html

 

So I would expect the G-6 to climb at 17.8-17.9m/s with Auto Rads and around 20 on manual. 

 

 

Therefore the Difference is rather small, and definetly offset by the introduction of Emergency power in mid 1943. 

[III/JG2Gustav05]

Nice finding, Klaus!

base on information below G6 only has 0.6m/S slower than G2 in climb rate.

The Bf109G-2 with MG151 Pods achieved 17.1m/s

The Bf109G-6 with MG151 Pods achieved 16.5m/s

 

As I remember that standard BF109G's radiator thermostat setting is 100C. so practical value with auto rad should be higher than 17.9m/S.

Edited January 6, 2016 by III/JG2Gustav05

[6./ZG26_Klaus_Mann]

Nice finding, Klaus!

base on information below G6 only has 0.6m/S slower than G2 in climb rate.

The Bf109G-2 with MG151 Pods achieved 17.1m/s

The Bf109G-6 with MG151 Pods achieved 16.5m/s

 

As I remember that standard BF109G's radiator thermostat setting is 100C. so practical value with auto rad should be higher than 17.9m/S.

I'm not 100% sure, but I think thats at least one of the many causes of confusion when it comes to the bf109 radiators and related performance. 

[Askania]

It's all in the testing process. For the 109s the Radiators have an enormous impact on rate of climb, due to the extreme openings they can achieve, acting almost as airbrakes.

 

Erla did much of their testing with new machines designated to enter combat. So in order to protect the not yet properly run in engines they performed their tests with the thermostat set to roughly 80-90°C, or 50% radiators. This test gives us best rates of climb of 18.5m/s below 2000m

 

In Rechlin they performed a single line of tests for almost closed radiators on a late production G-1. This is the test that resulted in 21m/s. 

 

All other 109s were tested to ERLA Standards, which means that as a Starting point is 18.5m/s, and the increase for closed radiator openings lies right about 13.5%

 

In a compilation  [http://www.kurfurst.org/Performance_tests/109G1-6_datasheet/109G_perftable.html]the G-2 Recce Variant acheived 18.2m/s, which is close to the other ERLA Values and therfore very much usable. 

 

The Bf109G-2 with MG151 Pods achieved 17.1m/s

The Bf109G-6 with MG151 Pods achieved 16.5m/s

The Bf109G-6 with taller tail unit (heavier) did 17.5m/s http://www.kurfurst.org/Performance_tests/109G_Leistungzusammenstellung/Leistungzusammenstellung109G.html

 

So I would expect the G-6 to climb at 17.8-17.9m/s with Auto Rads and around 20 on manual. 

 

 

Therefore the Difference is rather small, and definetly offset by the introduction of Emergency power in mid 1943. 

 

IIRC

 

these climb rates were achieved at SL

 

for example

 

The Bf109G-6 with MG151 Pods achieved 16.5m/s

 

Edited January 30, 2016 by Askania

[III/JG2Gustav05]

I'm not 100% sure, but I think thats at least one of the many causes of confusion when it comes to the bf109 radiators and related performance. 

Erla's test condition is too strict, can not represent practical combat condition, even VVS test shows 20m/s at SL, 4'24" to achieve 5000m.

Edited January 10, 2016 by III/JG2Gustav05

[II/JG17_HerrMurf]

According to Kurfurst's site G6 should be heavier than G2 90kgs instead of 150kgs. underwing 2cm MG 151/20 cannons are 215 kg instead of 330kgs I mentioned above. Any wartime pilot account mentioned big performance degraded from G2 to G6?

Honest question here. Is the Kurfurst site reliable/unbiased? I've seen some quote it rather religiously and others discount it.

[JtD]

The information is good, but personally I don't agree with everything in the discussion/analysis. I'd recommend the site to everyone for the information, and - as always, with every source - to develop your own opinion.

 

Kurfürst has a history of emotionally discussing some issues, but many folks do, and this should not be held against the information he provides.

Edited January 10, 2016 by JtD

[II/JG17_HerrMurf]

Understood.

[6./ZG26_Klaus_Mann]

Erla's test condition is too strict, can not represent practical combat condition, even VVS test shows 20m/s at SL, 4'24" to achieve 5000m.

That's because the Automatic radiators have a much smaller opening in Real Life conditions than they did at Erla Testing Facilites, and that caused roughly 2.5m/s 13% drop in climb performance. 

[III/JG2Gustav05]

The information is good, but personally I don't agree with everything in the discussion/analysis. I'd recommend the site to everyone for the information, and - as always, with every source - to develop your own opinion.

 

Kurfürst has a history of emotionally discussing some issues, but many folks do, and this should not be held against the information he provides.

Thanks for your input JtD, I understand that my G6's climb rate estimation is not sophisticated. no professional avaivtion calculation involved.  

even though I think that my 4'37" result pretty matches the report I listed prevously  http://www.wwiiaircr...-18-205-001.pdf

[Sgt_Joch]

Honest question here. Is the Kurfurst site reliable/unbiased? I've seen some quote it rather religiously and others discount it.

 

On the whole, it has very good reliable info. I have read pretty much all the stuff he has on there. 

 

I would say he has a slight LW bias since he always interprets the data in the manner which is the most favorable to the Germans, but OTOH, I have a slight pro-Russian bias myself.

 

It is always better to look and compare as many sources as possible, wwwiiaircraftperfomance.org is equally as good as Kurfurst IMHO.

Edited January 11, 2016 by Sgt_Joch

[II/JG17_HerrMurf]

Yah, I've seen that site as well.

[FTC_Riksen]

So now that the G6 is coming what do you guys think will be the climbing performance? Based on the docs and discussion presented here, I think 19m/s at 1.3 sea-level should be reasonable. Can anyone provide more specs about the early G6 version, like speed and important upgrades?

 

Cheers

[DB605]

So now that the G6 is coming what do you guys think will be the climbing performance? Based on the docs and discussion presented here, I think 19m/s at 1.3 sea-level should be reasonable. Can anyone provide more specs about the early G6 version, like speed and important upgrades?

 

Cheers

 

Early 1943 G6 is exactly same plane as G4 but with 13mm Mg's. Bulges in engine cowlings (for larger magazines of mg's) reduced top speed around ~9km/h's compared to G4.

 

It was only 15kg's heavier so i'm pretty sure climb performance will be pretty much same as G4 too.

[III/JG2Gustav05]

One thing I want to emphasis is that with Allied pilot believed popular number--17.7m/S, which is even worse than the G2 with MG151 Gondolas version, how could RLM pick such subtype which has both firepower and flight performance decreased to replace its predecessor?

[Dutchvdm]

Just wait and see what the team will bring us with the new G-6. I found the decrease in performance for the G-4 not that big. 

 

G-2

 

Maximum true air speed at sea level, engine mode - Combat: 530 km/h
Maximum true air speed at 2000 m, engine mode - Combat: 577 km/h
Maximum true air speed at 7000 m, engine mode - Combat: 656 km/h

Service ceiling: 12100 m
Climb rate at sea level: 21.0 m/s
Climb rate at 3000 m: 19.5 m/s
Climb rate at 6000 m: 16.5 m/s

Maximum performance turn at sea level: 22.2 s, at 270 km/h IAS.
Maximum performance turn at 3000 m: 28.3 s, at 270 km/h IAS.

 

G-4

 

Maximum true air speed at sea level, engine mode - Emergency: 540 km/h

Maximum true air speed at sea level, engine mode - Combat: 517 km/h
Maximum true air speed at 2000 m, engine mode - Combat: 564 km/h
Maximum true air speed at 7000 m, engine mode - Combat: 640 km/h

Service ceiling: 11800 m
Climb rate at sea level: 20.1 m/s
Climb rate at 3000 m: 18.9 m/s
Climb rate at 6000 m: 15.4 m/s

Maximum performance turn at sea level: 21.2 s, at 270 km/h IAS.
Maximum performance turn at 3000 m: 27.2 s, at 270 km/h IAS.

 

Grt M

[II/JG17_HerrMurf]

I was able to use an old BOS Alt/Airspeed chart for all aircraft to determine where and when to engage. And just as importantly where NOT to engage. Lots of pretty colored lines on the speed curves and easy to see where you or the enemy had speed advantages. :Anyone have an all Kuban chart like that yet?

[MiloMorai]

On the whole, it has very good reliable info. I have read pretty much all the stuff he has on there. 

 

I would say he has a slight LW bias since he always interprets the data in the manner which is the most favorable to the Germans, but OTOH, I have a slight pro-Russian bias myself.

 

It is always better to look and compare as many sources as possible, wwwiiaircraftperfomance.org is equally as good as Kurfurst IMHO.

 

'Slight' LW bias.        

 

The data selected is chosen for putting the 109 in the very best light.

[Panthera]

'Slight' LW bias.      

 

The data selected is chosen for putting the 109 in the very best light.

 

Well atleast then it's no different than the wwiiaircraftperformance site, which originally started as the spitfireperformance site.  I'd say that site seems religiously dedicated towards showing Allied fighters in the very best light possible whilst on the contrary only the very worst performance numbers for the German aircraft are presented.

 

That said both sites are good for source material from which to draw your own conclusions, whilst the conclusions of the site owners obviously need to be taken with a large amount of salt.

[Max_Damage]

Low quality of production and btw the g6 used wood in its construction late on. I think it used to have a wooden tail section.

[MiloMorai]

Well atleast then it's no different than the wwiiaircraftperformance site, which originally started as the spitfireperformance site.  I'd say that site seems religiously dedicated towards showing Allied fighters in the very best light possible whilst on the contrary only the very worst performance numbers for the German aircraft are presented.

 

That said both sites are good for source material from which to draw your own conclusions, whilst the conclusions of the site owners obviously need to be taken with a large amount of salt.

 

I see you weir blinkered rose tinted glasses.

[Panthera]

I see you weir blinkered rose tinted glasses.

 

Erm... you sure you're not talking about yourself? Your avatar kind of speaks volumes...

Edited January 16, 2018 by Panthera

[JtD]

Really guys? Neither of the sites (or any similar one) deserves any bashing. Maybe you give anyone who puts in loads of time and money to make all this information freely available to us a little bit of credit.

 

I have copies of ALL records related to the Hawker Hurricane that I could find at the National archives at home and ALL relevant performance data found therein, no matter how good or bad, can be found on wwiiaircraftperformance.org. There is nothing left out, nothing selective - so no bias at all. I cannot tell you how much more I appreciated the wealth of information provided by others, be it on the web or in a book, after I had spend the time and money I spend on researching the Hurricane. It's vastly under-appreciated by most people.

Edited January 16, 2018 by JtD

[Panthera]

Really guys? Neither of the sites (or any similar one) deserves any bashing. Maybe you give anyone who puts in loads of time and money to make all this information freely available to us a little bit of credit.

 

I have copies of ALL records related to the Hawker Hurricane that I could find at the National archives at home and ALL relevant performance data found therein, no matter how good or bad, can be found on wwiiaircraftperformance.org. There is nothing left out, nothing selective - so no bias at all. I cannot tell you how much more I appreciated the wealth of information provided by others, be it on the web or in a book, after I had spend the time and money I spend on researching the Hurricane. It's vastly under-appreciated by most people.

 

Problem with ww2aircraftperformance as I see it is that it tries to directly compare Allied & German aircraft based on the information it selectively provides (we've all seen the homemade graphs on the site), hence it seizes to be objective IMO. That doesn't mean it isn't a good source on Allied aircraft, it surely is, however it's severely lacking when it comes to the German types, and thus it shouldn't be attempting to draw comparisons - but that's how it originally started anyway when it was called spitfireperformance. 

 

In short I appreciate both sites, but I also don't kid myself when it comes to why the two places were created in the first place. 

Edited January 16, 2018 by Panthera

[MiloMorai]

Luftlovers always mention the 109s selected on Mike's site. They make much ado about stating it is outright bias which it would be if the designation and/or WNr was not given.

 

Do you find a list of data or a graph easier to understand, Panthera?

[JtD]

Can you point me to a single source that provides more flight test reports for the Fw190 than wwiiaircraftperformance does? It has at least 50, which is pretty much all the NASM had under the tags of Fw190 flight trial and performance. What is lacking and selective about all?

[Panthera]

Can you point me to a single source that provides more flight test reports for the Fw190 than wwiiaircraftperformance does? It has at least 50, which is pretty much all the NASM had under the tags of Fw190 flight trial and performance. What is lacking and selective about all?

 

Sites? Why does it need to be a site?  Personally I prefer the original source, and there are plenty of good books out there with more data as well. Take Dietmar Hermann's book on the aircraft for example.

 

Reading through Dietmar's book on the Long Nose for example it becomes quite clear that Mike Williams has an agenda when it comes to how he wants the aircraft to be percieved by anyone who visits his site, the last sections on this page being particularly cringeworthy to read tbh:

http://www.wwiiaircraftperformance.org/fw190/fw190d9test.html

 

Why Williams first chooses to qoute Dietmar on some specific flight performance data only to later qoute Caldwell when it comes to flight characteristics is odd, esp. when there's lots of first hand information about the Dora's flight characteristics in Dietmar's book, including how it compared with the radial types. Instead Williams chooses Caldwell's own version which doesn't correlate with any of the comparative tests conducted by the Germans themselves. 

 

 

Luftlovers always mention the 109s selected on Mike's site. They make much ado about stating it is outright bias which it would be if the designation and/or WNr was not given.

 

Do you find a list of data or a graph easier to understand, Panthera?

 

 Luftlovers? What are you then? 

 

It's pretty hard to take you seriously when you use words like those...

Edited January 16, 2018 by Panthera

[JtD]

Sites? Why does it need to be a site?

It doesn't, which is why I said "source".

 

Dietmar Hermann in no single book I know of him provides transcripts or pictures of 50+ flight test reports. He's credited with special thanks on wwiiaircraftperformance, though.

Edited January 16, 2018 by JtD

[Panthera]

It doesn't, which is why I said "source".

 

Dietmar Hermann in no single book I know of him provides transcripts or pictures of 50+ flight test reports. He's credited with special thanks on wwiiaircraftperformance, though.

 

You need to read his books on the 190 series.

 

Also lots of other performance graphs are available on the 190 that are NOT available on ww2aircraftperformance, even if I'm sure Williams could easily obtain them. All it takes is abit of digging around in archives yourself, and most places are even willing to send you scans of microfilms for you, a service I've had the pleasure of recieving multiple times on various subjects.

[JtD]

I usually take copies of the microfilms and scan them myself.

 

You can send the information you have to the site and I'm sure they'll be happy to publish it, copyright permitting (if not, you can still produce a homemade chart that references the original sources). This way you can very constructively right the wrongs you've found on the site.

Edited January 16, 2018 by JtD

[Panthera]

I don't really feel the need to "right any wrongs" by Williams, he's free to write what he wants, I just only ever use his site for quick information on Allied aircraft. If I need specific information on the performance of certain German aircraft I have lots original source material to pick from on my own harddrive and in books.

[JtD]

Well, lets go to Bodenplatte aircraft, open up a topic on the D-9 and lets see what we can learn about the D-9. In addition to the cringeworthy information provided by the site. I'd be happy to learn if there's anything new, the devs might be interested, and we'd let this topic be about Bf109G-6 climb rates again.