rel4y

Lets be reasonable here guys. There are certainly people who feel the need for an advantage in a comparison of airplanes.. that equates to dong size comparison stuff and is plain stupid. And please dont mix all sorts of topics into one, this thread here should be concerned with level speed of the BF 109 K4. The real point here is, we have a simulation of what is supposed to be as close to the real deal as it gets. Problem being if your using drag model data of a G14 mostly and neglecting the aerodynamic changes that were made due to inconsistency of historical data you are essentially creating a a visual K4 model with G14 flight model, which in my oppinion should not be an option in top notch flight simulation. IIRC there were two different german flight tests which incorporate data on tailwheel drag. The complete retraction of the long tailwheel definitely causes a level speed increase above of the 3-4 km/h mentioned by YoYo. If russian sources state differently there is no reason to assume them being more accurate, as german engineers would have no reason to cheat themselves. Furthermore to state 2% lower speed values fits a certain margin of error maybe theoretically correct, but should not resemble what should be the goal and also the interpretation is off. The stated performance figures are going to be reached with well-built serial production machines for certain. Emphasis being on for certain here. Also I dont see how relative performance to another aircraft matters if were trying to simulate the Bf 109 K4. Not everybody buys a module to dogfight something, some people might be just happy to fly the sim of a legend perfectly reproduced. Ill be looking out for the second report on drag reducing measures, meanwhile please dont derail this thread.

I was about to post that link as well, thanks Kurfürst. That test is in my opinion actually absolutely legitimate.

Im guessing that is compared to a partially retractible tailwheel on F/ early G models, since it talks about G2-4 models. The long Spornrad of later G models induced much more drag arrested (G14/G10) vs fully retracted (K4). The long Spornrad was necessary to employ 500kg bombs with appropriate ground clearence and improve forward visibility. 3-4 km/h improvement doesnt sound right at all to me. :O I would expect such a small low drag airframe with an 1850 HP engine to climb like hell btw so I wouldnt be suprised if climbrates reached up to 25 m/s. Especially if your hypothesis of neglected exhaust thrust is correct! If it is one thing a 109 was build to do, then its climbing fast (as an interceptor is supposed to do). Edit: Happy Christmas by the way and thanks for your correspondence YoYo.

In YoYos link the 109 does have "faired bumps" for mg 131. It says fixed tailwheel and uses apparently GM1 system which was not used during testing. It did not incorporate MW50 as it says combat power only was used and GM1 was mentioned. Edit: Graph says 1.3 ATA. I think Hummingbird has a valid point here. The G14 chart says "erflogene Werte" which means it is a real flight test.

With prop pitch settings corresponding to 2600 RPM I get max 573 km/h at SL, 1.8 ATA MW50, radiator 3/4 closed, 100% fuel. Still not close to the charts.

Ok, I tested as well. Were the tests conducted by the germans with 100% fuel quantity? I started with 100% fuel and took the screenshots probably 40-50s into the run, after settings the radiators and leveling out. Prop pitch was on auto and altitude was 7500 m +-8 m at FTH, 8 m +-2 m at SL. Weather effects were set to zero. Max speed at SL was 569 km/h IAS. Max speed at FTH was 468 km/h IAS. I have no time to convert it to EAS, feel free to tell us though. :)

Merry Christmas guys!

I want to go to Las Vegas! :D