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Messerschmitt Bf 109 K-4


for how long does the MW-50 work?

 

edit: is it even modeled?

ofcourse not im sure its weight added on plane but no performance change. maybe soon™ lets add more camo on lalas  :Ps

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Armament weight:

  • 2хMG131 + MK 151/20 - 135 kg
  • 2хMG 131 + MK 108 - 170 kg

 

So when can we see the 20mm for the BF-109K-4?

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Hello, just a little note on the F2 model. (Sorry, it doesn't have its own thread...) 

 

I tested the best climb speed of the fully upgraded F2. I expected that all 109 models starting from F onwards should have it's best climb speed at 270 kmh (same basic aerodynamics). 

So I tested 270, 250 and 290. 250 was best of the three. Then I tested 230 and it proved even better. After this I decided to not do any further testing as the best climb speed was clearly off the mark. 

 

I did these tests a couple of days ago and seem to have lost my notes, so no exact figures for you, sorry. 

But this is easy to test and verify yourself

 

Edit: 

I found the numbers!

I did a 2 minute climb starting from 1,000 m with 100% throttle, no WEP. 

Margin of error is +/- 5 m and +/- 2.5 km/h. I only did one test with 30 min fuel for each airspeed as this was meant to just give me an idea of how to fly the plane...

(I know this doesn't fit the method, but since the purpose isn't to actually determine the climb rate, but the best speed, it will suffice) 

 

IAS - delta H - Climbrate

230 km/h - +2,245 m - 18.71 m/s

250 km/h - +2,230 m - 18.58 m/s

270 km/h - +2,140 m - 17.83 m/s

Edited by Colonel_Panic
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Sustained 360 deg turn at 1000 m: above 22 sec      What do you mean here, what speed is the turn performed at? Speed really changes turn speed and the K4 accelerates like a rocket

 

Never exceed speed (IAS):
       Altitude band, km                IAS, kmh

                   0-4                               750            Clearly this is to compensate for compression not being ingame, but these numbers are way too low, the 109s could adjust
                   4-5                               700            the entire tail section with the trimmer mid flight to exit dives above their critical mach number, so compression wasn't limiting
                   5-7                               600            their diving, the airframe was solid and could endure much higher speeds than 750 IAS please make this like it was in 1.35
                   7-9                               500

 

The slats on the 109 don't seem to do much, the plan has a very bad tendency to stall and get in spins, the exact opposite of how it was in real life

It also feels like a nose heavy brick always pointing down the moment you roll to the side making it really hard to aim properly

 

in the ingame description its stated it has the ability to have x3 MK 108 cannons, please add that

 

Many K4s had Flettner tabs too, significantly improving high speed roll performance, please add that at least as an available upgrade

Edited by i_ivanof
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Sustained turn is a 360 deg turn, in which your altitude stays within +-20 meters, and IAS within +-5kmh. You need to make a series of at least 3 such turns and calculate the averedge

These are the numbers from the actual flight manual and you can provide some tests results on a production aircraft - we would be very interested

Slats can't be modeled with needed accuracy atm. But despite that the plane was still prone to spins due to its design

Data sheets will be reworked completely on a different platform

Flettner tabs were introduced in 1.37, we are struggling to get them functioning properly once again
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First, optimal speed for turn time is something determined by testing, in reality. Experiment.

 

Second, that turn time is actually quite good (and just a bit worse then turn time for 109G2 tested at 1km altitude). More speed does NOT equal faster turn time above a certain point, because to pull maximum possible Gs (aerodynamically, limited by high speed stall) you would have to blackout the pilot (which happens fairly fast for ww2 pilots without anti-G suits) or overstress the airframe (or run into control stiffness at very high speed), and you could not maintain that speed in a turn. Turn time of course goes higher the higher you are.

 

Third, those limitations are probably taken from a pilot manual or something of the sort. All pilot manuals you find, all of them, have dive limit in indicated airspeed much reduced at high altitude. Why?

 

At 9km, 500km/h indicated is 799 km/h true airspeed. However, at 9km, speed of sound is only 1092 km/h, so at 500km/h indicated you are actually going at 0.73 mach, which is quite high. In addition, due to lower air pressure, flutter is more likely to develop and vibration is more amplified; that's why in mach number terms, the limit is often lower the higher you go up on many planes.

 

Which is why the limit is set so "low" - it only looks low in IAS, because 0.73 mach for a Vne (which is supposed to have some safety margin) isn't low.

Edited by Cpt_Branko
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Sustained turn is a 360 deg turn, in which your altitude stays within +-20 meters, and IAS within +-5kmh. You need to make a series of at least 3 such turns and calculate the averedge

These are the numbers from the actual flight manual and you can provide some tests results on a production aircraft - we would be very interested

Slats can't be modeled with needed accuracy atm. But despite that the plane was still prone to spins due to its design

Data sheets will be reworked completely on a different platform

Flettner tabs were introduced in 1.37, we are struggling to get them functioning properly once again

well it's good to know you're working on it

 

Passing the the Vne doesn't mean losing your wings seconds later, in fact that rarely happened in ww2 combat aircraft. Flutter wasn't as big of a problem for most planes as compression and controls stiffness, which usually occurred at lower speeds. Many Finnish pilots claimed to have gone way past the 109's Vne and were just fine, here are some of their quotes, most interesting one is  how a damaged burning 109 G6 dived from 7k, extinguished the fire, reached 950+IAS (it was the speed gauge's max) and survived. Pilot tube pressure buildup might have given them somewhat exaggerated results but they are were likely way above the Vne of 750 IAS  and didn't disintegrate like you would in warthunder at the moment.

 

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

Edited by i_ivanof
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Well, without compressibility implemented, planes have to desintegrate artificially at some point because the real reasons for both airframe failure and high drag, stability issues, flutter and so on are just not there.

 

I would suggest that at least the civil aviation standard should be used (basically, 11% safety margin between maximum tested without (risk of) damage and manual-listed Vne).

Edited by Cpt_Branko
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RLM regulations required the aircraft's airframe to withstand 30% higher maximum permissible speed that was specified in the manual.

 

A bf 109G model (I think it was a G-2) was successfully tested to up to 0,81 mach (992 km/h), and even then the thing that was most stressed was the prop shaft, not the airframe. The airframe withstood the test and the pilot was able to land without problems.

Edited by Narushima
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RLM regulations required the aircraft's airframe to withstand 30% higher maximum permissible speed that was specified in the manual.

 

A bf 109G model (I think it was a G-2) was successfully tested to up to 0,81 mach (992 km/h), and even then the thing that was most stressed was the prop shaft, not the airframe. The airframe withstood the test and the pilot was able to land without problems.

Was that a standard production model or did they reinforce it, or close gunports or anything else like that? Reminds of that Spitfire that reached mach .94.

Edited by Nabutso
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RLM regulations required the aircraft's airframe to withstand 30% higher maximum permissible speed that was specified in the manual.

 

A bf 109G model (I think it was a G-2) was successfully tested to up to 0,81 mach (992 km/h), and even then the thing that was most stressed was the prop shaft, not the airframe. The airframe withstood the test and the pilot was able to land without problems.

 

Interesting, thanks, I suspected the safety margins were higher in the day (for obvious reasons), but could find no concrete number. Any idea on safety margins other airforces used?

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Sustained turn is a 360 deg turn, in which your altitude stays within +-20 meters, and IAS within +-5kmh. You need to make a series of at least 3 such turns and calculate the averedge

These are the numbers from the actual flight manual and you can provide some tests results on a production aircraft - we would be very interested

Slats can't be modeled with needed accuracy atm. But despite that the plane was still prone to spins due to its design

Data sheets will be reworked completely on a different platform

Flettner tabs were introduced in 1.37, we are struggling to get them functioning properly once again

It was very stable at low speed due to slats and had a lot of buffeting, but when it went into spin it was violent and hard to recover. (at least what I've read)

 

 

Mark Hannah test pilot about landing in a 109:

 

"This is one of the most controllable aircraft have flown at slow speed around finals, and provided you don't get too slow, it is one of the easiest to three point" 

"The only problem is getting too slow, if this happens, you very quickly end up with a high sink rate and with absolutely no ability to check or flare to round out"

http://www.eaf51.org/newweb/Documenti/Storia/Flying_%20109_ENG.pdf

Edited by _Solty_
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Interesting, thanks, I suspected the safety margins were higher in the day (for obvious reasons), but could find no concrete number. Any idea on safety margins other airforces used?

 

No idea. I assume the Brits would use similar margins than the Germans. I know the American used lower margins, at least for the P-38, P-51 and P-47.

 

Anyway, I found this dive test, it's both in German and English. It's a 109F with G model wings:

http://www.wwiiaircraftperformance.org/me109/Diving_Test_109F_W.Nr.9228_ger_eng.pdf

 

According to Kurfurst "they used an early version of the tall tail unit in this dive test, originally used on the Werknummer 14 026 test bed, see: http://kurfurst.org/Performanc...ung109g601e605a.html"

Edited by Narushima
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Hmm can i ask why the Devs chose a prototype model of the K-4? This data matches the Thin blade prop tests, in which it was only prototyped, never put on production models. 

 

Again why are we told production models only?

 

[Spoiler]

http://kurfurst.org/Performance_tests/109K_PBLeistungen/files/5026-18_DCSonder_MW_geschw.jpg

[/spoiler]

 

Hopefully the K-4 gets better now they have decent data...

Edited by Espada_2
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  • 2 weeks later...

(...) I know the American used lower margins, at least for the P-38, P-51 and P-47."

 

That is not fully correct. They used Indicated margins that were lower  in relation to the actual critical speed.

The reasoning was very simple: the USAAF realised soon that american pilots were more propense to push their aircaft to the limit, often with deadly consequences, specially when the P-38 started to be issued. This "cowboy" mentality resulted in several acidents involving those particular fighters (that were at the time the most recent and advanced in US service), and due to that all new US fighters were red lined to speeds that were in fact perfectly safe, normally below a "safety margin of 1/3".

 

That is why often pilots pushed both the P-51B/C and the P-47 above the stated "never exceed speed" - around mach 0.7; and lived to talk about it.  By the end of ww2 it was common knowledge that both P-51 and P-47, red lined at +/- 505  mph, were able to recover from speeds up to 570 mph (mach 0.8+) .But since the same didn't happen with the F-4U , Hellcat and P-38 and others,  the  oficially Indicated Never exceed speed was not changed..

 

In the end of 1945 during USAAF research tests regarding high speed dive and compressibility effects , P-51D's and P-47D's were dived at mach 0.85 (that is around 605  mph) with minimal stress on the airframe, and later at mach 0.87 ( +620 mph ) when they start to develop distortions in the wing area where the machines guns were seated.  

 

The final report - that I believe can be found in the aircraf performance site - states that both fighters could safely reach  mach 0.82, 

Shortly after they were officially cleared for speeds up to  Mach 0.8, information that is still present in fhe fact file of the P-51 in one of the USAF sites.

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Hmm can i ask why the Devs chose a prototype model of the K-4? This data matches the Thin blade prop tests, in which it was only prototyped, never put on production models. 

 

Again why are we told production models only?

 

[Spoiler]

http://kurfurst.org/Performance_tests/109K_PBLeistungen/files/5026-18_DCSonder_MW_geschw.jpg

[/spoiler]

 

Hopefully the K-4 gets better now they have decent data...

It is not the Thinblade one, because according to your chart the plane reached nearly 730 kmh at 6k, not 716 like the one stated by the dev.

 

And http://kurfurst.org/Performance_tests/109K_PBLeistungen/files/5026-26_DCStart_noMW_geschw.jpg says the the  9-12159 is the "Serienschraube" which means standart prob in german, while the Thinblade one is the 12199.

Edited by Reidlpwner
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  • 3 weeks later...
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you misinterpret my words - i never implied that turn performance was taken from the original manual. this was an answer to this post regarding velocity restrictions

 

turn performance of G-series was taken from the russian research institute flight tests. speaking of the K-series performance - numbers i saw in russian literature were about 23-24 seconds for 360 sustained turn due to weight increase

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  • 3 weeks later...

Shouldn't we be calling this engine a DB 605-DC instead, given that it's modeled with C3 fuel and MW50?

 

Also, I wish I could run this at 1.8 ATA which is the takeoff and emergency power without MW50. Instead of having a choice between "open all the taps with MW50" and the modest "kampfleistung" at 1.45 atm and 2600 rpm... But I suppose you'll have to model MW50 running out first. Or would you? Double WEP anyone? The data sheet has that wrong, by the way, it says that combat power is 2800 RPM, but it's actually 2600 RPM on both the DB and DC.

G-10 datasheet has same error. In game it's as it should be.

 

src

http://kurfurst.org/Engine/DB60x/DB605_datasheets_DC.html

Edited by Meruru
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turn performance of G-series was taken from the russian research institute flight tests. speaking of the K-series performance - numbers i saw in russian literature were about 23-24 seconds for 360 sustained turn due to weight increase

 

Thank god the German FMs are relying on totally unbiased information from independent third-party Soviet evaluations which were completed during the Stalin era!

 

We can finally feel completely confident about the accuracy of the flight models for German planes like the K4 and G10 now that we know the developer isn't relying on original data from German testing or post-war evaluations by the British and the Americans.

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Thank god the German FMs are relying on totally unbiased information from independent third-party Soviet evaluations which were completed during the Stalin era!

 

We can finally feel completely confident about the accuracy of the flight models for German planes like the K4 and G10 now that we know the developer isn't relying on original data from German testing or post-war evaluations by the British and the Americans.

You have turnrate data for the 109G series from German, American, or British testing? 

 

What would make Russian tests any more or less bias than German, American, or British ones? Home country stuff is obviously preferable but... like I said above, if you have any, why not give us a look?

 

And keep in mind he's just referring to the turnrate here. FMs as a whole aren't designed with Russian tests only, for example. You can check the datasheets provided and match them up perfectly with home-country data.

Edited by Nabutso
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