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

[Chingachgook]

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[pbfoot]

Originally Posted by lesofprimus

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

hence that old saying "beware of the Hun in the sun"

[lesofprimus]

Pretty funny there ching...

[Glider]

Originally Posted by 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

Udet
Only just alive, I have been in hospital after being diagnosed with cancer which was picked up 6-8 weeks late, hence the absence. Wasn't a well boy when I went in, but am responding well to treatment, although the hair has gone.

To business.
The tactical losses the RAF sufferred in 1941 I put down to the same tactical disadvantages that the Germans suffered in the BOB. The RAF in short range aircraft were operating on the 'wrong side of the English Channel. The Germans had good radar, could see them coming and were able to get into position to intercept.
A lot of damaged planes were not going to make it home and pilot who bailed out was lost, whereas German planes could evade and make emergency landings. I wonder how many Germans were saved by the superiour dive of the 109?
Re tactics our tactics for escorting were based on close escort (at least in the earlier stages) a tactic that was fatally flawed. The RAF had the additional disadvantage in that a majority of the RAF squadrons were still flying Vic formations which was a lesson still to be learnt. Finally the larger raids were escorting bombers often Blenhiems or Sterlings neither of which was fast making the raids easy to intercept.
I have little doubt that had the Germans been flying Spits and the RAF 109F's the RAF would still have suffered these losses. As we all agree it was the 190 in 1942 that brought on the Black Period for the RAF in the West

In the desert the 109F was giving the Allied Huricanes and P40's a very hard time of it and it wasn't until the Spit MkV was deployed did things even up.

Personally I have always wondered why the RAF spent so much effort attacking France in 1941 which was never going to achieve anything strategically and yet refused to use those Spit V's to equip squadrons overseas that were fighting using obsolete Hurricanes. There is no reason why the Middle East squardons couldn't have been equipped with Spit V's long before they received them. Let alone the Far East. Spits may not have stopped Japan but they would have stood a much better chance.

[Udet]

Hello Glider:

Sorry to know of the health problems you are enduring; you have my most sincere and heartfelt wishes: don´t give up and have a prompt recovery!

I do not have time to comment more on the airplanes, but i will be back later or another day.

Cheers Glider!

[delcyros]

Yes, Glider, I second your thoughts. But prior to this, take care of Your health, Glider, my very best whishes to You.

In the desert the 109F was giving the Allied Huricanes and P40's a very hard time of it and it wasn't until the Spit MkV was deployed did things even up.

In Africa, the Bf-109F also had trop filters, which should lead to a significant reduction in performance. I would still put my favour on the F4 against the Spit V, altough as far as I see, most Bf109 of the JG 27 were Bf109F2 and E7 until mid 1942, when they only briefly received F4 until they got the more versatile G2 later in 42.

[delcyros]

Further thoughts

What if the BF 109F4 actually achieved 670 Km/h? Shouldn´t the G2 be faster due to a more powerful engine?

Perhaps. Compare:
Kurfürst - Mtt. AG. Datenblatt, Me 109 G - 1. Ausführung

The test results show a max. speed of 632-664 Km/h (depending on individual aircraft) with:
radiator flaps 120mm open, while the usual opening was 40mm at "Schnellflugstellung"
but more seriously:
The DB 605 wasn´t cleared for WEP, so this speed also only is for "Kampf- und Steigleistung" -powersetting

This is beeing confirmed in the latter part, where the G1 achieved 660 Km/h at 7000m altitude. But here again the engine wasn´t cleared for WEP, and thus those climb- and speed figures are attained on normal, 30min. sustainable 100% powersetting.

Factoring this into comparison, the G1 and G2 indeed were faster than the F4 at the same 100% powersetting (G2: 660 Km/h; F4: 635 Km/h).
But how fast could they go with WEP?

The difference is striking for the DB 605:
at 100%: 1310 hp @ 0ft.
with WEP: 1450 hp @ 0 ft.

Since the airframe is the same and all other factors beeing equal, the 10.687% power increase should lead to a 2.67% speed increase (You need four times the power to double the speed under lab condition), or in other words, the same G1 testplane should be able to go 678 Km/h (421 mp/h) at 7000m altitude for brief times using WEP (Bf 109G1).

Now back to our Bf109 F4 with DB 601E and 635 Km/h at 100% and 6400m / (640 Km/h at 6700m) altitude*):
at 100%: 1200 hp @ 0ft.
at WEP: 1350 hp @ 0ft.

The 12.5% increase in power should translate into a 3.125% increase in speed at our reference altitudes for WEP, ergo the same Bf109F4 testplane should be able to go 655 Km/h at 6400m or 660 Km/h (410 mp/h) at 6700m using WEP powersetting (Start- und Notleistung).
I conclude that the 670 Km/h figure is off by 1.5% from the expected one.
Perhaps an individual plane in excellent state may go that fast but it cannot be expected that all production models achieve this speed under the given circumstances. My thought.


Since the BAL limits for production models were 3% (+-), this is in within acceptable tolerances.

*) Kurfürst - Mtt. AG. Datenblatt, Me 109 G - 1. Ausführung
the dataset shows 660 Km/h @ 6200m altitudes for 100% (Kampf- und Steigleistung) powersetting for the BF 109F4 (not G1 as the link name imply)which does not agree to the 635 Km/h attained by other tests. The explenation may be that this specific test -unlike others- wasn´t recalculated for compressibility effects, as the author suggest (check notes). Confirmation comes from OKL Typenblätter, as this dataset was not used furtherly for entry into Typenblatt.

[Glider]

Udet and Delcyros appreciate your thoughts. Delc, the last posting does raise some interesting questions about the relationship between the F4 and the G2. Wish I knew the awnsers

[Sgt. Pappy]

*Salute* Glider, God speed with your health exams... Here's hoping you get better not soon... but NOW.


The Spitfire V may have been inferior to the 'Freidrich' (109F) but first you have to include things like speed/energy retention, stall speed (and essentially wing loading), roll rate at all speeds, etc. It's not just accel. and speed, and climb rate that wins the battle, though those are very useful assets for a fighter.

Considering the pilots are equal, and are both very good, the SpitV may be quite untouchable and even a danger. We have 4 main tactics - BnZ (Boom and Zoom in which the pilot dives to gain speed, attacks and zoom climbs w/ that speed until out of range), which was the 109's main tactic, theres the TnB (turn and burn which is simply turn fighting), the RnD (Rope and Dope, which utilizes the zoom climb to hang pitiful, slower enemies trying to follow up), and we have maneuver fighting.. i.e. scissors, rolling scissors, splitS etc.

The spitV's better roll at lower speeds and better turning allow it to split S or maneuver away from the 109. A scissors would maul the 109 as well. Both planes generally have the same aerodynamics when fully 'cleaned up', but the Spitfire's ability to outturn the 109 eventually will end up in a non-sustained turn fight .. the 109 attempting to find a long range deflection shot as the spit turns to evade. If the 109 resumes attempts at the BnZ, the spit pilot will continue to outmaneuver the Freidrich. The best SpitV pilots could dodge the BnZ with no or little loss of altitude and speed. The clipped wing V's also were very useful as they rolled similarly to the Butcher Bird, which had worse turning than the 109 at lower speeds. If the 109 even tries an RnD, a good spit pilot will level out to gain speed while the 109 loses it all. Many-a-time has the good Spitfire pilot shot down the 190 during 1941 and beyond. Don Gentile is one of them, who, on his first sortie in the SpitV shot down 2 x 190's.

(BTW, if anyone knows of any Spitfire V cutaways, please fill me in!)

[delcyros]

The Spitfire V may have been inferior to the 'Freidrich' (109F) but first you have to include things like speed/energy retention, stall speed (and essentially wing loading), roll rate at all speeds, etc. It's not just accel. and speed, and climb rate that wins the battle, though those are very useful assets for a fighter.

That is all very true.
My question is how would You measure energy retention? This is a general question as it don´t belong to Spit and -109 exclusively. To answer this might help to judge other planes as well.
The 109F2 and SpitV were perfectly equal.
The F4 -for me- seems to be the peak in development of the 109. The G2 even tops the acceleration, climb and top speed but for significant tradeoffs in low speed handling (heavier airframe). The G4 barely matches the F4 in performance and is inferior in terms of handling but it is more versatile, has a heavier punch and a more rugged undercarriege (which always was a weakness for 109 - just another strange similarity to the spit).

[Smokey]

What about the K4?

[loomaluftwaffe]

what about it?

[Smokey]

Given its performance, isn't the K4 a contender for the ultimate Bf109 development?

[Sgt. Pappy]

The Bf109K-4 was a very high-end of the 109 performance envelope. It's agility was equalt, if not, slightly better than that of the G's, since, essentially, the G's were F's with tonnes of extra armament and weight. I would personally choose the K-4 because of its insane speed and nice climb rate, not to mention its accuracy.

Delcyros, it is quite difficult to measure energy retention, but one has to be creative. You can measure it like this: grab some speed in a dive, level out when you hit a certain speed and record the speed to which your a/c drops after 30 seconds, then a minute, then 90 seconds.

[delcyros]

That makes sense. But we cannot use it other than via autopsy of the flight performance of warbirds, requiring expensive tests.

I can hardly say something to the K4 as I don´t yet read details to this plane other than general information. It seems to be quite heavy and limited in handling.

It probably also is underrated in IL-2 as I never could turn with a Pe-2 in a 109K. But if this is true, it´s bad.