Comparative Tests Spitfire Mk V vs. Me 109 G

[klemchen]

Hello,

let me start by wishing everybody all the best for the New Year.

Now my problem: Probably in early 1944 the Germans equipped a captured Spit V with a DB 605 A engine for comparative tests to a Me109 G with the same engine. From some Me 109 internet site (I do not remember where) I got two sheets from the "Archives of M. Williams", of originals probably by Daimler Benz, comparing speed and climbing performance of both aircraft. According to these sources, the weight of the Spit was only 2730 kg, probably because it had been stripped of armament and equipment, and that of the Gustav 3030kg by one sheet and 3100 kg by the other. The 109 turned out a little faster at all altitudes, while the spit climbed considerably better.
Now my question: Does anybody know what subtype of G the 109 tested was? The weight of 3030 kg seems to point to an early version (G-1 to G-4), while the 3100 kg would rather suggest a G-6 or G-5, the former being the mass production version at that time.

Regards,
klemchen

[Andy Mitchell]

klemchen,

Unfortunately, I can offer nothing rwegarding the 109 but can direct you to an article regarding the Spitfire (EN830) being fitted with a standard DB 605A-1 (Wk Nr 00701990).

Weight of 2730 kgs was without armamant which was estimated to be another 300 kgs.

See the Luftwaffe Wiki Downloads Page and look for the article "Spitfire in Wolfs Clothing"

[Kurfürst]

Given the top speeds shown and the weight of 3100 kg, I would suspect a G-5 or G-6; also because its called 'Me 109 Serie' on the graph - only the G-6 was in production in May 1944 when the report was dated.

The 3030 kg figure is probably a result of correction for less fuel after taking off and climbing to altitude.

The report was BTW posted very long ago in August 2003 by someone who I cannot remember exactly, probably at Olivier's board; properly the credit should go to someone else for this document than the one who branded it.

Here's the unbranded version for reference:

[George Hopp]

The report was BTW posted very long ago in August 2003 by someone who I cannot remember exactly, probably at Olivier's board; properly the credit should go to someone else for this document than the one who branded it.

You make a valid point, Kurfürst!

And, the title "Comparative Tests Spitfire Mk V vs. Me 109 G" is a bit misleading because, as I recall, either DB or Mtt simply wished to check the efficiency of the DB 605 in the Spitfire compared to its efficiency in the 109. Further, the test pilots apparently loved flying the Spitfire, thinking of it as a well-bred lady compared to the antics of the 109.

[yogybär]

I wonder why the Spit was 300kg lighter then the 109G...

[George Hopp]

According to these sources, the weight of the Spit was only 2730 kg, probably because it had been stripped of armament and equipment, and that of the Gustav 3030kg by one sheet and 3100 kg by the other. The 109 turned out a little faster at all altitudes, while the spit climbed considerably better.

According to the DB report of 18 May 1944, the weight of the Spitfire V with the RR 45 engine and armament was 3030kg. With the DB 605A and armament removed it was 2730kg.

The Bf 109G is not identified, so was probably just a company aircraft. I would tend to think that the weight of the a/c was 3100kg, and that the 3030kg in performance sheet #4 was just a data transcription error.

[Kurfürst]

Originally Posted by yogybär

I wonder why the Spit was 300kg lighter then the 109G...

IIRC the armament was removed from the Spitfire when fitted with the DB engine, hence the lighter weight and much improved climb rate.

AFAIK the DB 605 used the testbed Spitfire V was 605B from a Bf 110G, though this would only differ in gearing ratio and perhaps in its aux. systems from the 605A fitted to the 109G.

[Graham Boak]

If the armament added 10% to the weight, then the climb rate can be reduced by 10% to allow for this.

More thorough work would have replaced the off-the-shelf propellor/gearing with one tuned to the aircraft, or rather the requirements - though this would be unlikely to make more than a small improvement, and is not particularly relevant to the purpose of the test.

The actual value of the exercise appears obscure.

[klemchen]

Hello,

thank you all very much for your answers.
I consider these tests as a comparison of the two aircraft involved because I feel the best way of comparing the performance potentials of two similar airframe designs would be to equip both with the same engine and prop and then match their performances with each other. The reason I asked for the 109 subtype was that I wanted to know if both aircraft flew with their tailwheels in the same position. As far as I know, that of the Spit V was non-retractable as was that of later Gustavs, while that of very early ones was retractable. Flying the Gustav with its tailwheel extended or retracted made a difference of 12 km/h top speed at sea level.
Of course there was an amount of variance of performance between individual aircraft of the same type, so one cannot draw too far reaching conclusions from the comparison of just two.

Regards,
klemchen

[George Hopp]

The actual value of the exercise appears obscure.

It appears to be to compare the efficiency of the DB 605A in the Spitfire compared to that of the 109G, therefore lots of info on the effectiveness of the oil coolers and radiators.

The reason I asked for the 109 subtype was that I wanted to know if both aircraft flew with their tailwheels in the same position. As far as I know, that of the Spit V was non-retractable as was that of later Gustavs, while that of very early ones was retractable.

Be assured, klemchen, the 109G would have had a fixed tailwheel unit.