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Some opinion about maneuverability of Bf109K-4


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That is exceptionally bad result between captured aircraft test and captured aircraft was shotdowned once. I couldn't believe it could be perfect performance.

Finnish 109s weren't "captured" they were delivered mostly brand new from Germany because Finland was Germany's allies for most of WW2 duration.

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Finnish 109s weren't "captured" they were delivered mostly brand new from Germany because Finland was Germany's allies for most of WW2 duration.

 

 

That G-2 was not finnish tested aircraft. USSAF or RAF tested it northern africa.

Why German sent Bf109G-2/Trop to finnish? It is tropicalized aircraft.


Edited by gomwolf
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I cannot understand why yak and other aircrafts came out in this thread. What is going on?

 

Whatever This is P-51D and Bf109K-4 Lowspeed turning performance result.

 

https://www.youtube.com/watch?v=sKu0HvQ0DKU?feature=player_detailpage

I don't know how to embeding video in this page. That youtube tag does not working.

 

Test configuration is basic configuration of mission editor. 65% fuel for P-51D and 100% fuel for Bf109K-4. I want to keep speed and altitude in turning but, I couldn't. Especially Bf109K-4 easily get high speed and easily stall at high AoA. I noticed altitude and speed when finished turning.

At first thread, I told Bf109K-4 and P-51D have same turning perfromance but it was incorrect. Bf109K-4 can turn one circle to around 19.5 sec, and P-51D 21.5sec. Bf109K-4 can turn fester than P-51D in DCS.

 

 

 

Now please talking about historical and aerodynamical something.


Edited by gomwolf
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That G-2 was not finnish tested aircraft. USSAF tested it northern africa.

Why German sent Bf109G-2/Trop to finnish? It is tropicalized aircraft.

 

The 170km/h stall speed belonged to Finnish test, which was a normal G2

 

As for the "USAF" test (British to be exact), incase you didn't know the tropicalized version is, well, tropicalized, and has worse performance than normal version, has quite a bit worse performance and 100kg or so heavier.

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Whatever This is P-51D and Bf109K-4 Lowspeed turning performance result.

 

https://www.youtube.com/watch?v=sKu0HvQ0DKU?feature=player_detailpage

I don't know how to embeding video in this page. That youtube tag does not working.

 

Test configuration is basic configuration of mission editor. 65% fuel for P-51D and 100% fuel for Bf109K-4. I want to keep speed and altitude in turning but, I couldn't. Especially Bf109K-4 easily get high speed and easily stall at high AoA. I noticed altitude and speed when finished turning.

At first thread, I told Bf109K-4 and P-51D have same turning perfromance but it was incorrect. Bf109K-4 can turn one circle to around 19.5 sec, and P-51D 21.5sec. Bf109K-4 can turn fester than P-51D in DCS.

 

 

 

Now please talking about historical and aerodynamical something.

 

The P51D has bad power to weight ratio, it can't sustain the turn rate like the K4, it's simple. 35% fuel load bring the turning capability closer, but the K4 as strong torque to the left so it doesn't turn well to the right,

 

Turn time = combination of turn radius (stall speed) and sustain turn rate (power to weight ratio, mostly)


Edited by GrapeJam
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And features 400+ more horsepower to energize that root section, thus the power on stall speed clean was probably the same 130 km/h.

 

 

Actually, that is not right, turning speed can be same with lighter one, if weight and power both rised. When weight going up, stall speed direct proportion with it. However total CLmax does not change, if there is no change shape.


Edited by gomwolf
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The 170km/h stall speed belonged to Finnish test, which was a normal G2

 

As for the "USAF" test (British to be exact), incase you didn't know the tropicalized version is, well, tropicalized, and has worse performance than normal version, has quite a bit worse performance and 100kg or so heavier.

 

 

Where can I found that stall speed test result?

 

The reason I asked it to Flugmuesum is I cannot find any German or Axis test result in offline and online both.

Actually, there is a reference of stall speed of Bf109G-2 in Soviet it was same with 170kph, but it was Bf109G-2 with gondola gunpod.

 

 

 

And Bf109G-2/Trop does not heavier than normal one. The sendfilter of Bf109 is not heavy like British one.

http://kurfurst.org/Performance_tests/109G_Leistungzusammenstellung/Leistungzusammenstellung109G.html

Watch number 17.


Edited by gomwolf
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Actually, there is a reference of stall speed of Bf109G-2 in Soviet it was same with 170kph, but it was Bf109G-2 with gondola gunpod.

 

Sources?

 

The tested Finnish G2 didn't have gun pods.

 

And funnily enough, G2 with gunpods is still more than 100 kg lighter than the K4.

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Sources?

 

The tested Finnish G2 didn't have gun pods.

 

And funnily enough, G2 with gunpods is still more than 100 kg lighter than the K4.

 

Stalling speed is just a factor of calculating CLmax and CLmax is the factor changed by shape of aircraft, not weight.

And where can I find that finnish test result?

 

This is my reference.

http://www.wwiiaircraftperformance.org/me109/Me-109_G2_14513_Russian.pdf

Watch Page 33 and 43.

 

 

 

Actually, I have to go to work now(6:20AM here.) I will see it later.


Edited by gomwolf
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Is this thread already almost 20 pages???

What is it all about?

 

 

Making up our props I had to perform some tests and processed their data. As a side product these SUSTAINED TURN graphs were obtained (not a direct time measuring but rather G at zero longitidinal acceleration or dHe/dt =0). Full tanks (P-51 - wing tanks). At sea level (50-200 m). WEP, and both MW-50 powere rates.

 

109K wins sustained turn within the whole 300 - 520...550 kph range. Dora is better starting from approx. 400...420 kph.

 

All planes are very unpleasant at IAS<300 kph, and lower speeds have no profit regarding the turn rate and dangerous for the engine because of insufficient cooling.


Edited by Yo-Yo

Ніщо так сильно не ранить мозок, як уламки скла від розбитих рожевих окулярів

There is nothing so hurtful for the brain as splinters of broken rose-coloured spectacles.

Ничто так сильно не ранит мозг, как осколки стекла от разбитых розовых очков (С) Me

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Where can I found that stall speed test result?

 

The reason I asked it to Flugmuesum is I cannot find any German or Axis test result in offline and online both.

Actually, there is a reference of stall speed of Bf109G-2 in Soviet it was same with 170kph, but it was Bf109G-2 with gondola gunpod.

 

 

 

And Bf109G-2/Trop does not heavier than normal one. The sendfilter of Bf109 is not heavy like British one.

http://kurfurst.org/Performance_tests/109G_Leistungzusammenstellung/Leistungzusammenstellung109G.html

Watch number 17.

 

180 to be correct... but it could be gunpods effects on the wing stall.

 

Anyway, 170 kph seems to be right for the clean wing and 3300-3400 kg.

Ніщо так сильно не ранить мозок, як уламки скла від розбитих рожевих окулярів

There is nothing so hurtful for the brain as splinters of broken rose-coloured spectacles.

Ничто так сильно не ранит мозг, как осколки стекла от разбитых розовых очков (С) Me

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W

And Bf109G-2/Trop does not heavier than normal one. The sendfilter of Bf109 is not heavy like British one.

http://kurfurst.org/Performance_tests/109G_Leistungzusammenstellung/Leistungzusammenstellung109G.html

Watch number 17.

 

And the weight of the sand filter is....."-"

 

Mean while BF 109 G6/trop is 100kg heavier than normal G6.

me-109g6-16476-pg7-1400.jpg

 

Stalling speed is just a factor of calculating CLmax and CLmax is the factor changed by shape of aircraft, not weight.

 

You're not telling me the K4's wings with 2 huge bulges are the paragons of cleanliness that benefit clmax, are you?

 

And where I can find that finnish test result? My reference will update here soon.

 

According to virtualpilot.fi it was done by pilot Pekka Kokko on 5.6.1943, Kurfurst did a translation of that test so you may ask him

 

This was the tested 109

MT-215.jpg

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The 170km/h stall speed belonged to Finnish test, which was a normal G2

 

And again, it was described as uncertain even in the report. My guess is they were using an instrument placement that got effected by propwash, and as such the speed readings were jumping up and down. And again the altitude of the stall is not described, but it would've no doubt been at a safe altitude, the British for example often did power off stall tests at around 8-10 kft height.

 

Anyway stall figures from the period are notoriously inaccurate, often differing greatly in between tests, even with pretty much the same aircraft. For example the British tested a P-51B which they had stall at a remarbly low 84 mph IAS clean, power off, flaps up, at 9200 lbs. Then later a P-51D which stalled at 94 IAS mph, clean, power off at 9000 lbs. That's a 200 lbs lighter weight, yet a 10 mph higher indicated stall speed.

 

Now what does that tell you? I.e. that IAS stalling speeds from the era aren't the most reliable piece of data around ;) That's why I like looking at take off distances for example, as they were easily measured and kind of "concrete" ;)


Edited by Hummingbird
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180 to be correct... but it could be gunpods effects on the wing stall.

 

Anyway, 170 kph seems to be right for the clean wing and 3300-3400 kg.

 

Engine off.

 

Engine on and you get that nice benefit of the slats as the root section suddenly can keep on lifting at the same amount as the slatted area. Hence the rather remarkable 130 km/h clean stall speed with power on, which is 2 mph slower than a F4U-1 in the same condition.

 

By comparison the P-51 should stall at around 89-90 mph TAS, power on, clean, flaps up.


Edited by Hummingbird
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And the weight of the sand filter is....."-"

 

Mean while BF 109 G6/trop is 100kg heavier than normal G6.

me-109g6-16476-pg7-1400.jpg

 

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

It looks something wired. Watch the table at last part(It is same report with that chart). There is two kinds of weight in there at same condition. and most weight of clean condition of Bf109G-6/Trop is 6,856lb(3,109kg).

 

 

 

 

You're not telling me the K4's wings with 2 huge bulges are the paragons of cleanliness that benefit clmax, are you?

 

I already told about that kinds of shape change at first thread.

 

 

 

According to virtualpilot.fi it was done by pilot Pekka Kokko on 5.6.1943, Kurfurst did a translation of that test so you may ask him

 

This was the tested 109

MT-215.jpg

 

I already read it and there is "other data(Not noticed where they found it)", not pekka Kokko's one. Even it was not "clearly defined."

 

I really have to go to work now.


Edited by gomwolf
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Engine off.

 

Engine on and you get that nice benefit of the slats as the root section suddenly can keep on lifting at the same amount as the slatted area. Hence the rather remarkable 130 km/h clean stall speed with power on, which is 2 mph slower than a F4U-1 in the same condition.

 

By comparison the P-51 should stall at around 89-90 mph TAS, power on, clean, flaps up.

 

What kind of power-on stall do you mean, i.e. 1g or in turn?

Ніщо так сильно не ранить мозок, як уламки скла від розбитих рожевих окулярів

There is nothing so hurtful for the brain as splinters of broken rose-coloured spectacles.

Ничто так сильно не ранит мозг, как осколки стекла от разбитых розовых очков (С) Me

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And again, it was described as uncertain even in the report. My guess is they were using an instrument placement that got effected by propwash, and as such the speed readings were jumping up and down. And again the altitude of the stall is not described, but it would've no doubt been at a safe altitude, the British for example often did power off stall tests at around 8-10 kft height.

 

You use one test as an indication of all tests again?

 

Anyway stall figures from the period are notoriously inaccurate, often differing greatly in between tests, even with pretty much the same aircraft. For example the British tested a P-51B which they had stall at a remarbly low 84 mph IAS clean, power off, flaps up, at 9200 lbs. Then later a P-51D which stalled at 94 IAS mph, clean, power off at 9000 lbs. That's a 200 lbs lighter weight, yet a 10 mph higher stall speed.

Yeah, 84 mph IAS clean at 8000 feet is going to be totally the same at SL.

 

Anyway, when was the last time we see TAS lower than IAS?

 

Now what does that tell you? I.e. that IAS stalling speeds from the era aren't the most reliable piece of data around ;) That's why I like looking at take off distances for example, as they were easily measured and kind of "concrete" ;)

IAS stalling with altitude stated= unreliable, but take off distance is, ok. Nevermind power to weight ratio play a big part in take off distance.
Edited by GrapeJam
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He's talking about a level flight power on stall.

Source of 130km/h power on stall.

http://www.virtualpilots.fi/feature/articles/109myths/

Other data: stall speed clean 170 km/h (could not be clearly defined). The nose sunk and the plane banked calmly to the right wing. At landing configuration the stall speed was 145 km/h. With full power the plane could be held hanging from the prop at 60° nose-up attitude ASI showing 130-140 km/h.
Since when is "hanging from the prop at 60" nose-up altitude" level flight? And it's clearly stated as IAS.
Edited by GrapeJam
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F4U was tested in the same condition and stalled at 135 km/h.

 

The F4U stalled in power on clean configuration at 84 knots, not mph. 84 knots is 99mph, which is whoop de doo, 5 mph lower than power off.

 

I hope you're not telling me because the G2 can prop hang at 140km/h, thus it's gonna outturn a Corsair, a Hellcat or a Spitfire IX.


Edited by GrapeJam
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The F4U stalled in power on clean configuration at 84 knots, not mph. 84 knots is 99mph, which is whoop de doo, 5 mph lower than power off.

 

Yes, you don't get that much benefit from energizing the root if the outboard wing section can't keep up. A 5 mph reduction is then entirely within expectation.

 

Also you do realize this is higher than the indicated stall speed of the P-51, right? :D Yet the F4U still whooped the P-51 in the turn.

 

Again, what does that tell you about the reliability of these stall speed figures? esp. when compared side to side :P

 

I hope you're not telling me because the G2 can prop hang at 140km/h, thus it's gonna outturn a Corsair, a Hellcat or a Spitfire IX.

 

I suppose prop hang is some special ability that the 109 has? :megalol:

 

The F4U was tested in the exact same condition and stalled at a higher speed.

 

It's called the minimum flying speed, and if one aircraft can keep flying level at a slower speed than another, then that also means that its got more available lift & power to sustain a turn than the other aircraft.


Edited by Hummingbird
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Yes, you don't get that much benefit from energizing the root if the outboard wing section can't keep up. A 5 mph reduction is then entirely within expectation.

 

Also you do realize this is higher than the indicated stall speed of the P-51, right? :D Yet the F4U still whooped the P-51 in the turn.

 

Again, what does that tell you about the reliability of these stall speed figures? esp. when compared side to side :P

 

Nope, this is CAS, indicated the F4U's stall speed is quite a bit lower.

 

 

I suppose prop hang is some special ability that the 109 has? :megalol:

 

The F4U was tested in the exact same condition and stalled at a higher speed.

Source?

 

It's called the minimum flying speed, and if one aircraft can keep flying level at a slower speed than another, then that also means that its got more available lift & power to sustain a turn than the other aircraft.

Yep, G2 can outturn F4U, Hellcat, Spitfire IX you hear it first from Hummingbird. Now would you mind buying a DCS Jet module, get in, do a climb test and see that even climbing at 60" the AOA is the same as level flight?
Edited by GrapeJam
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Nope, this is CAS, indicated the F4U's stall speed is quite a bit lower.

 

 

Source?

 

Yep, G2 can outturn F4U, Hellcat, Spitfire IX you hear it first from Hummingbird. Now would you mind buying a DCS Jet module, get in, do a climb test and see that even climbing at 60" the AOA is the same as level flight?

 

I don't think you understand that if you can "hang" at 130 km/h then that means you haven't stalled yet.

 

The same would be the case with the F4U, although since it doesn't have slats it would be at a slightly lower angle (I'm pretty sure its 60 deg from the vertical, and 30 from the horizontal btw) and at 135-145 km/h.

 

And yes, I do believe that the 109G could slightly outturn the F4U, but NOT the Spitfire or Hellcat. (Might be able to match the Hellcat)


Edited by Hummingbird
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