Bf-109F-4 and a bleak time for RAF

[Chingachgook]

X

[delcyros]

Hi Twitch, I always use to enjoi our disussions!

Originally Posted by Twitch

A 2-3 minute WEP use is dubious at best to categorically state that 416 MPH was a true usable velocity to quote as an everyday speed to expect.

Probably. As pointed out above, speed depends on more issues. Individual state of airframe and engine beeing the most important. German planes always suffered from a briefer allowed use of WEP than -let´s say- US planes.
2-3 min. are very worthy for rapid climbs and stand up acceleration. That´s what opens the distance in run and that what´s closes the distance in a chase, both very credible advantages for the F4.
However, note that the WEP was forbidden to use by special maintenance orders for a certain timeframe (reasons for this are unknown).

Originally Posted by Twitch

Certainly no manuscript attributes more than 390 as a top end for the F-4 even Heinz Nowarra in Germany who had all the records of Messerschmitt to draw upon in his 1964 book The Messerschmitt 109.

That´s wrong. The documents given in the source are primary sources, Nowarra had secondary docs on hand and never dealt with the sources itself. And as the author points out, german primary sources do consistently show a 670 Km/h max. WEP /6700m speed figure for 1942-43. He knows more than just a few.
Even if You decide to neglect the WEP, the max. speed (30+ minutes sustainable, unlike those of the Spits!) at "Steig- und Kampfleistung"- powersetting for 6000m is consitently 635 Km/h (394 mp/h) at 6000m and more like ~400 mp/h at 6700m respectively. That is still superior and unlike other planes with boost fairly sustainable.

Originally Posted by Twitch

Rechlin performance evaluations for other aircraft state some higher than standard top speeds observed also.

In comparison to what? Rechlin -except from Karlshagen maybe- had the most decent speed measuring devices avaiable. Perhaps other measurements were less sensitive? The example with the Do-335 is misleading as You are comparing two unidividual planes. The Do-335 AV-prototypes at Rechlin were flown without guns and ammo unlike those to be used by Luftwaffe Ekdo. This has been noted on the -335 testcharts. None such notes occur in case of the 109F4 tests (similar testresults are also reported from Augsburg with a 665 Km/h max. speed using WEP at 6800m).

Originally Posted by Twitch

A speed advantage is not an end-all decides-all factor in combat either. It climb is initally 4,350 FPM but that's not consistant through all altitudes either.

Initial climb is given for "Steig- und Kampfleistungs"-powersetting. At WEP its more like 4500-4650 fpm, gradually reducing with altitude.

Originally Posted by Twitch

Speed by itself is not a decisive factor unless we compare jet with piston of 150-200MPH advantage.

Tell that the red republicans at Spain! Or the french in 1940. Or the japanese in 1944. A speed advantage of at least 20, better 40 mp/h is comfortable for ww2 fighters. And it´s getting more important once pilots adopt for the energy thinking.

[Chingachgook]

X

[Glider]

I have read this thread with nterest but at the end of the day I have never read or heard about any Allied Pilot in a MkV who felt that he was at a disadvantage against a 109F. I am not saying that the Spit had clear superiority, but that they were an even match with victory down to the best led units and or tactical position.

I do not believe that 416 was achieved in regular combat in a 109F. If it had the SpitV would have suffered the sort of casualties that the did against the FW190, which was truly capable of 410 in normal combat conditions.

I do agree that if a plane had a speed advantage of 20 to 30MPH over an enemy aircraft then that had a considerable advantage which would have been noticed by the opponent. As mentioned above, the RAF to the best of my knowledge didn't consider the SpitV to be outclassed by the 109F so any additional performance of the 109F must have been limited.

An obervation about the filters fitted to the Spit in the desert, which certainly had an impact on the performance. The RAF didn't fit them for the fun of it and I was wondering what the Germans did to deal with the problem of the sand. If anyone can help with this it would be appreciated as its something that has always interested me.

[Hop]

Top speed was flown on a measured mile with Askania Theodolits and recalculated for atmosspheric circumstances as it was typical by that time.

Do you have a source for that? There was an extensive discussion on another board, with the author of the site that published the documents on the F4 test, and nobody was able to offer proof either way about whether the figures were adjusted for compressibility.

And as the author points out, german primary sources do consistently show a 670 Km/h max. WEP /6700m speed figure for 1942-43. He knows more than just a few.

From what I remember of the discussion, there were no other tests giving similar figures.

[Hop]

I have read this thread with nterest but at the end of the day I have never read or heard about any Allied Pilot in a MkV who felt that he was at a disadvantage against a 109F.

That's a good point. The RAF were certainly concerned by the Fw 190, but the 109 just didn't cause the same fear. And the Luftwaffe switched over to the 190 on the Channel front as quickly as they could, which again seems strange if the 109 had a 40 mph speed advantage over the Spitfire.

[twoeagles]

Every Spitfire pilot was at a disadvantage against the 109 he didn't see in time...

[Chingachgook]

X

[Glider]

Originally Posted by twoeagles

Every Spitfire pilot was at a disadvantage against the 109 he didn't see in time...

Any pilot is at a disadvantage against any plane that they didn't see in time.

For example, I think the first RAF plane to shoot down a German aircraft in WW2 was a Lysander. The Wirraway that shot down a Zero, Arado 196 floatplanes had a number of kills and there are loads of other examples from all sides which people could mention.

[Udet]

Lord Glider, good to see you are still alive and healthy out there.

While i believe when you say you have not yet heard of any Brit pilot who flew the Spitfire Mk. V affirming he felt he was at disadvantage when confronting the 109 F, you might as well consider the following significant issues:

How would you explain the losses of RAF fighter squadrons during 1941 in western europe?

Let´s see, by 1941 the alleged plans for invading England had been cancelled (the so called Seelowe thing), the bulk of the jagdgeschwadern was sent east in preparation for the unleashing of Barbarossa.

Two geschwadern remained in the west to guard against the "winner" of the Battle of Britain: Richtofen and Schlageter.

Yup, 1941 was not a year of intense aerial action in the west, as it became a secondary theather of operations; however the 109s kept a very comfortable upper hand when confronting the Sptifire Mk Vs during such period of time.

It is noteworthy to mention that during 1941 the stab, I, II and III/JG 2 and stab., I, II and III/JG 26 had precisely the improved 109 F-1, F-2, and later that year the F-4 as the main toys to fight the RAF´s Mk Vb and Vc, not forgetting a number of the late Es remained in service for some time.
The Fw 190 was not the mainstay of JG 2 and JG 26 throughout 1941.

Acknowledged is the fact the introduction of the Fw 190 A in full the following year (1942) implied a black period in the history of the RAF but the 109 Fs -and their pilots- proved superior to the British airmen flying the Mk Vs.

I can agree the technical charts and specification sheets might indicate the 109 Fs and the Mk V were pretty well matched, but when we step out of the classroom to see what battle records indicate, the 109 F proved superior to the Mk Vs.

What do you think Glider?

Cheers

[Chingachgook]

X

[delcyros]

The single most decisive factor in aerial dogfight is pilot skill.
The Fw190 may make a good pilot out of a mediocre one due to
heavy firepower, ruggedness and maneuverability over a wider
range of speed.
However, most LW aces stayed to their Bf109´s once they
exploitet it´s merits.

[delcyros]

Originally Posted by Hop

From what I remember of the discussion, there were no other tests giving similar figures.

The author gives more tha one:
The Leistungsdatenvergleich Fw-190A and Bf-109F/G of dez. (?) 1941:
Beim-Zeugmeister: Seite 2 - Erste Tests
The JG-26 comparison between Fw-190A and Bf109F4 ( it states that the F4 is 10-20 Km/h faster than the Fw190A at altitude while both are equal at medium altitude with a slight advantage for the Fw190A at low alts
Beim-Zeugmeister: Seite 6 - Vergleich BF 109 F-4 und FW 190 A-2, Teil 2
The OKL Typenblatt doc from june 1942, again stating 670 Km/h top speed for the Bf-109F4:
Beim-Zeugmeister: Seite 9 - Übersicht OKL
The Messerschmidt Typenblatt showing a figure of 660 Km/h in 6200m:
Beim-Zeugmeister: Seite 10 - Firmendaten Messerschmitt, Teil 1
Finally the Messerschmidt company intern performance charts for the Bf109F4, dating 1943:
Beim-Zeugmeister: Seite 12 - Firmendaten Messerschmitt, Teil 3

So confirmation comes from three sources via various docs: Rechlin test flights, Company documents and comparison charts from military units (JG26).

Originally Posted by Hop

There was an extensive discussion on another board, with the author of the site that published the documents on the F4 test, and nobody was able to offer proof either way about whether the figures were adjusted for compressibility.

They should be adjusted for atmosspheric circumstances according to Zdiv(Ainring) 23/1938. Not following these guidelines for measurements would exclude the use of attained datas for entry into OKL Typenblatt.




True is that none of the british test revealed the correct datas as Britain did not possessed a single DB 601E nor a Bf-109F4 for test purposes. All datas have been extrapolated from Bf-109F2 with DB601N. The author of the british tests concluded that their figures should not be taken as the max. ones but AS THE MINIMUM ONES because the engines used were faulty, did not developed the design hp and required repeated maintenance, which in turn affected the performance and the assumption of speed for the extrapolated F4.

Originally Posted by Glider

I do not believe that 416 was achieved in regular combat in a 109F. If it had the SpitV would have suffered the sort of casualties that the did against the FW190, which was truly capable of 410 in normal combat conditions.

I too, at least for the timeframe up to late 1941. The use of WEP is reported to be allowed in early 1942 latest for combat according to a doc. The altitude at which this speed could have been achieved is rather not common for 1941/42 over France or in the med, at least for dogfights. But as the JG26 comparison flyouts showed, the F4 was not slower than the A4, at least in all but low level altitudes.

[Soren]

Hop,

You might as-well cut it, cause the speeds attained by the Bf-109F-4 are real - unlike so many Spitfire figures out there.

[lesofprimus]

The single most decisive factor in aerial dogfight is pilot skill.

delc, most decisive is the element of surprise, with pilot skill second....