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..

[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.

[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.

[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

[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.

[*Buzzsaw*]

Originally Posted by Kurfürst

Buzzsaw,

To answer your questions about the V15a, yes its an E-1, but no, I do not think there was any meaningful difference between the E-1 and E-3 aerodynamically. Only the fitted armament was different. Now one of the test you have posted show that there was 0 to 1 kph "difference" between the MG FF being present or not.Other than that there was a slight bulge under the cannon drum in the underside of the wing. I do not know what drag that was responsible for, but I do have British tests for the Spitfire which give a speed difference of a whopping 1 mph for the similar bulge for the Hispano ammo drums...

As for the V15a test, the full paper has been transcribed on my site
http://kurfurst.org/Performance_test...w_109V15a.html

and I have also recently uploaded the originals to this forum, you can find in one of my recent postings in another thread.

As for the 3 papers you have posted, they are turn times and radii for the 109E at 0 and 6000m, at various flap settings.

Salute

Sorry Kurfurst, your answer is clearly not accurate.

Firstly, You have not provided an original document which shows the loadout, weight, or boost levels of the the V15 aircraft. If you have the full test, show the originals, not transcribed incomplete sections.

Secondly, the V15 is clearly not a production aircraft, there were no production E-1's till late in 1938 and early in 1939. The date of the V15 test is April of 1938, long before any E models were produced. V15 is one of several prototypes produced to test the installation of the DB601 engine in a 109 airframe.

Here is a excerpt from 'Messerschmidt Bf 109' by Robert Grinsell. This is one of several sources I have consulted which clearly trace the evolution of the 109E model, and which are in general agreement. The section of relevance, begins with the 109E header.



As the above notes say, V15 was one of three early pre-production aircraft which were built in 1937 and which had the DB-601 installed and tested in various forms. These were V13, V14 and V15. I could not absolutely confirm a picture of V15, but I believe it is one of the lower or upper aircraft on the following page, as no others of this type were constructed. V14, the identical brother aircraft to V15 is definitely identified. You will notice there is no armament installed on V14 or the other two aircraft.



At this time, Germany was orchestrating a propaganda campaign to convince potential enemies that it had a formidable and powerful air force with aircraft which outperformed all opponents. At this time, Germany was potentially moving into a conflict situation over its claims on the Sudetenland and Czechoslovakia. In fact, the latest model of the 109 in service, the 109D, was slower and climbed worse than the initial model of the Hurricane then in service. The Luftwaffe attempted to mislead British and French observers by sending highly modified versions of the 109 to air competitions. Below is a picture of V13 in its initial form during the July 1937 Zurich International competition. In the case of the July event, V13 was equipped with a modified 1560 hp DB-601 engine, (misidentified in the caption as a DB600) which allowed it to win several events. These engines were designed to only last a few hours, used special fuels and boost levels. The Luftwaffe claimed their entries were 'production', in service aircraft, despite the fact no 109's were in service with Daimler Benz engines at that time. No armament was visible.



V14, also equipped with a 1560 hp DB 601, was also present, and flown by Ernst Udet, head of the Technical Office of the Luftwaffe, but it crashed. Below are pictures, again, no armament is visible.



In November of the same year, at a second international air competition, V13 made another appearance, in even more highly modified form. This time it was powered by a more heavily boosted DB601 which produced 1650 hp. This aircraft also had a large number of other modifications, including a special spinner, highly polished frame, and special radiators. And quite obviously, it has no armament. It achieved a top speed of 379 mph/607 kph at sea level. It was claimed to be a production, service aircraft. Seen below:



The aircraft was flown by Dr Wurster, the chief test pilot for Messerschmidt. You will notice that the V15 test also has Dr Wurster as test pilot. During 1937 and 1938 V15 was being used a testbed for various engine, boost, radiator, and oil cooler configurations. It continued in this role through 1938 and into early 1939, then was retired.

According to the several sources I consulted, it is clear this aircraft did not have standard armament, if any, and that it was equipped at various times with highly modified engines.

The fact the results of the posted V15 test are not duplicated by any other of the tested actual E series aircraft is a clear indicator its results were obtained with non-standard equipment.

Sources

'Messerschmidt Bf 109' by Robert Grinsell
'Bf 109, Versions B-E' by Roy Cross, Gerald Scarborough and Hans J Ebert
'Messerschmidt Bf 109' by Heinz J Nowarra
'Spitfire vs Bf 109' by Tony Holmes
'Messerschmidt Bf 109, Owners Workshop Manual', by Paul Blackah and Malcolm V Lowe

[Kurfürst]

Originally Posted by *Buzzsaw*

Salute

Sorry Kurfurst, your answer is clearly not accurate.

Firstly, You have not provided an original document which shows the loadout, weight, or boost levels of the the V15 aircraft. If you have the full test, show the originals, not transcribed incomplete sections.

Secondly, the V15 is clearly not a production aircraft, there were no production E-1's till late in 1938 and early in 1939. The date of the V15 test is April of 1938, long before any E models were produced. V15 is one of several prototypes produced to test the installation of the DB601 engine in a 109 airframe.

We are discussing V15a, not any of the previous prototypes like V15, V14 or V13.

Bf 109E-1 V-15a WNr. 1774 was the last in prototype I know of, it was fully armed with 4 x MG 17s and in representative condition of serial production aircraft, the complete testing paper was provided on this forum if anyone wants to doubt my transcription.

I am not discussing red herrings about previous or different aircraft, therefore on my part I have put an end to this part of discussion.