Bf109 test data

[Kurfürst]

IMHO the realistic max speed for the Bf 109E series, based on the V15a trials and the official specs and the French trials etc., are:



At SL.

DB 601Aa, 1,35 ata (1045 PS) : 498 km/h (V15a @ 1.35 = 498 km/h, Baubschrb.5% @ 1.35 = 500 km/h)
DB 601A, 1,30 ata (990 PS) : 489 km/h (V15a @ 1.31 ata = 493 km/h, French109 1.3ata = 485 km/h)*

DB 601Aa, 1,45 ata (1175 PS) : 515 km/h*
DB 601A, 1,40 ata (1100 PS) : 506 km/h*

Similiar boost in speed up ca. 1500 m, above: essentially 1.3/1.35ata performance levels, but boost is maintained, and fuel consumption increased to ca. 375 lit/h.

* Calculated from 1.3ata / 1,35ata results for 990 PS / 1075 PS

At altitude.

DB 601Aa, 1,35 ata : 570 km/h @ 4800 m (V15a @ 1.35 = 572 km/h, Baubschrb.5% @ 1.35 = 570 km/h, Swiss 109E-3a = 564 km/h)

DB 601A, 1,30 ata : 562 km/h @ 5200 m (V15a @ 1.33 ata = 562 km/h, French109 1.3ata = 485 km/h; 1942 Emil chart with 601A = 562 @ 5200)


P.S. Note that atmospheric conditions in the V15a and French trials are very close (+5, +6 Celsius) which explains as well why the results match so well.

Note that the 1942 Emil chart is again based on the V15a results. Given the weight it probably includes the armored bulkhead.

If CloD's 'standard day' is different from German (British) Standard day for which these figures were corrected to, then they should be re-calculated to CLOD standard day first.

[JtD]

Originally Posted by Kurfürst

At SL.

DB 601Aa, 1,35 ata (1045 PS) : 498 km/h (V15a @ 1.35 = 498 km/h, Baubschrb.5% @ 1.35 = 500 km/h)
DB 601A, 1,30 ata (990 PS) : 489 km/h (V15a @ 1.31 ata = 493 km/h, French109 1.3ata = 485 km/h)*

493 of V15 @1.31 were done at 500m altitude, at SL this was extrapolated to 485.

[Kurfürst]

Originally Posted by JtD

493 of V15 @1.31 were done at 500m altitude, at SL this was extrapolated to 485.

485 was not yet corrected to Normaltag (standard day) conditions as I understand.

It's curious though, I think it needs to be looked into. If you are right, it's an even closer match to French figures..

[JtD]

Originally Posted by Kurfürst

485 was not yet corrected to Normaltag (standard day) conditions as I understand.

It's curious though, I think it needs to be looked into. If you are right, it's an even closer match to French figures..

Yes, you are right, it's not corrected. If you apply the method they used for the Aa engine and use A-1 performance with 55 PS less at low altitude, you end up with 490 km/h (r = 0.993752), corrected both to standard days conditions at SL and nominal engine output.

[SiThSpAwN]

Just a a side note, me being someone that is in no way an expert on all this stuff, but it almost seems that what is being talked about here is almost out of the realm of what the CloD FM can calculate properly. As an example, how does it calculate weight correctly if its only based on either full or empty, no inbetween.

Now maybe I just dont understand their FM data and perhaps there are calculations going on that I dont see, but as you expend fuel, ammo, etc, the weight and flight characteristics will change.

So are we asking too much of the CloD FM? Would be interesting to hear what the programmer had to say about it, what knowledge he had on flight models, engineering background, etc... or if he is just a programmer punching in numbers without too much thought into what they actually are... if that makes any sense.

Not trying to rain on anyones parade or anything, just mostly a comment on the level the current FM could actually handle. And if throwing all this data around really matters if the FM itself can even really handle it.

[5./JG27.Farber]

Originally Posted by SiThSpAwN

Just a a side note, me being someone that is in no way an expert on all this stuff, but it almost seems that what is being talked about here is almost out of the realm of what the CloD FM can calculate properly. As an example, how does it calculate weight correctly if its only based on either full or empty, no inbetween.

Now maybe I just dont understand their FM data and perhaps there are calculations going on that I dont see, but as you expend fuel, ammo, etc, the weight and flight characteristics will change.

So are we asking too much of the CloD FM? Would be interesting to hear what the programmer had to say about it, what knowledge he had on flight models, engineering background, etc... or if he is just a programmer punching in numbers without too much thought into what they actually are... if that makes any sense.

Not trying to rain on anyones parade or anything, just mostly a comment on the level the current FM could actually handle. And if throwing all this data around really matters if the FM itself can even really handle it.

The weight throughout flight DOES make a difference in game. Easist test you can do is take a 109 with 10% fuel and a 250Kg bomb... Take off and drop the bomb, then repeat with 100% fuel... You will definatley see a dramatic difference.

[IvanK]

Originally Posted by 5./JG27.Farber

The weight throughout flight DOES make a difference in game. Easist test you can do is take a 109 with 10% fuel and a 250Kg bomb... Take off and drop the bomb, then repeat with 100% fuel... You will definatley see a dramatic difference.

Large change in Drag to in this method.

[bugmenot]

Originally Posted by Kurfürst

IMHO the realistic max speed for the Bf 109E series, based on the V15a trials and the official specs and the French trials etc., are:



At SL.

DB 601Aa, 1,35 ata (1045 PS) : 498 km/h (V15a @ 1.35 = 498 km/h, Baubschrb.5% @ 1.35 = 500 km/h)
DB 601A, 1,30 ata (990 PS) : 489 km/h (V15a @ 1.31 ata = 493 km/h, French109 1.3ata = 485 km/h)*

DB 601Aa, 1,45 ata (1175 PS) : 515 km/h*
DB 601A, 1,40 ata (1100 PS) : 506 km/h*

Similiar boost in speed up ca. 1500 m, above: essentially 1.3/1.35ata performance levels, but boost is maintained, and fuel consumption increased to ca. 375 lit/h.

* Calculated from 1.3ata / 1,35ata results for 990 PS / 1075 PS

At altitude.

DB 601Aa, 1,35 ata : 570 km/h @ 4800 m (V15a @ 1.35 = 572 km/h, Baubschrb.5% @ 1.35 = 570 km/h, Swiss 109E-3a = 564 km/h)

DB 601A, 1,30 ata : 562 km/h @ 5200 m (V15a @ 1.33 ata = 562 km/h, French109 1.3ata = 485 km/h; 1942 Emil chart with 601A = 562 @ 5200)


P.S. Note that atmospheric conditions in the V15a and French trials are very close (+5, +6 Celsius) which explains as well why the results match so well.

Note that the 1942 Emil chart is again based on the V15a results. Given the weight it probably includes the armored bulkhead.

If CloD's 'standard day' is different from German (British) Standard day for which these figures were corrected to, then they should be re-calculated to CLOD standard day first.

DB 601A, French109 1.3ata = 570 km/h @ 5000 m - 5500 m - Closed Radiators
http://kurfurst.org/Performance_test...formanceT.html



Regards

[klem]

Originally Posted by Kurfürst

....................................

If CloD's 'standard day' is different from German (British) Standard day for which these figures were corrected to, then they should be re-calculated to CLOD standard day first.

No, the CoD results should be converted to Standard Day (which my test mission does) to ensure all results are on a level playing field when they are compared (109, Spitfire, Hurricane etc)

I'll try to finish the 109 tests this weekend. It won't be "max speed tests" but a test at 2400 / 1.3 and 2400 / 1.35 to compare with historical charts and avoids arguments about what max speed power settings should be.

[Kurfürst]

BTW how do you measure TAS?