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

What about the K4?

what about it?

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

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.

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.

The Kurfurst did not have the agility portion of the performance review.... Speed yes, climbing yes, but it handled like a fat dog when compared to its contemporary enemies, the maneuverable Yak-3's/La-5 and 7s, and of course the Spits and Stangs...

As usual the clinical aspect of performance data has people clinging to the incorrect theory that this is what produces kills. Speed disparity, unless very great, is of little consequence in most situations of combat. Speed= energy must be kept to hold any advantage at all. Once a crate begins maneuvering velocity is scrubbed off sometinmes rather quickly depending on the plane.

A P-51 diving on a 262 can carry enough inertia to make a firing pass and hold that momentum for a given time. But once it is gone the jet will walk away. That said taking prop-driven opponents in a melee will not produce these dramatic results. A high speed diving firing pass and a zoom climb is not equivilent. Manuevering aircraft will be relatively matched even when one has a 30 MPH top speed level flight advantage.

It there any pilot account touting how he simply outsped his Spitfire opponent and dominated the fight becuase he had a few minutes of WEP? Much faster, later Spits had an advantage over 109Gs yet in most circumstances there are no RAF accounts of run away speed disparities in a a fight.

A plane able to climb steeply can't have lead drawn onto it if its pursuer can't climb as steeply even if it has a higher rate of climb at a given altitude. It might need a shallower angle of attack to produce rapid climb performance. If it is unable to point it nose higher for a prolonged period the opponent with better vertical performance can't be shot even if its FPM is less than the pursuer. To imagine two planes at the same angle of attack in a climb and the trailing plane closing the gap is unrealistic. No one simply pulled up and expected to climb away faster than ordance can travel.

The outcome of combats are usually due to tactical advantages. A section bouncing some unwary group below or a victim doing a split S and evading the fight are examples.

Someone mentioned the new program in the History Channel Dogfights on this sight. I've talked to some of these same men and their watermark combats are illustrated in this show very well. Pure level speed or the ability to simply climb alone are never decisive factors. The expertise to use your plane's strengths and exploit the enemy's is. This means a combination of performance and maneuvering skill, situational awareness with tactical advantages at hand.

No one performance factor alone was responsible for the outcomes of these combats. It came down to the human element and how they assessed the combat situation. People can tout speed alone as some mythical power but the reality of all the pilot combat dialogues proves otherwise.

I can fully agree with what You posted, Twitch.

8)

Chingachgook said:

This might belong on 109 thread, but I'm a noob and can plead ignorant.

After looking at old posts and finding Beim-Zeugmeister: Page 1 - Introduction I must ask some questions…

109f-4 under emergency power tested at 416mph (670km) @ 20k plus some scorching climb rates (DB601E clearance given in Feb '42).

Is this right? Was this power setting used in combat? Should all of the sims in the world be changed now?

DANG.

Spit Vb @ 20k = April '42 = 362mph (375 given for prototype).

Worse yet Vb Trop @20k = 352mph.

So the Brits were looking at a 54mph deficit in ETO and 64mph in the Mediterranean against the 109. That's bleak!

With that kind of speed advantage the turn rate/radius argument becomes almost totally irrelevant.

I am now no longer so impressed with Moelders, Marseilles, Galland, Rall etc (ok, I will always be impressed by Marseilles).

I am surprised that RAF kept their losses in the 2-3 to 1 range during 1942 especially given that most of them were still using awful tactics (3 plane vics!) and they had to deal with JG2+26 with FW190a.

So here is another question, why'd LW bother with the big bad Wulf? I know it looks cool, but seems like F could do all that and do it above 22k to boot.

Heck, even Merlin 61 engined IX was working at a 10-15mph disadvantage to the F.

It was not until early '43 that RAF had VIII and HF&LF IX that would match (almost) the F and by then the F is gone…

Oh the lure of the dark side…

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Agreed - the situation is even more bleek considering the mainstay was the badly outclassed Mk V until the end of 1943! MkIXs came into service very slowly, in mid-1943 there were still just 10 Sqns of them in Britain, compared to about 3 times as many MkV Squadrons.

While the 109F-2's superiority in speed was no small compared to the MkV when introduced, at least at low altitudes in 1941, the F-4s introduction in effect meant the RAF Spits were behind by a generation. In 1942 the F4s were cleared for full power, and as the Rechlin figures show, at altitude there was little contest and high speeds allowed the 109F to dictate the engagements. Then came the 109G, sometimes fitted with GM-1 to add to the insult, and it still faced the MkV.

A sidenote on 109-190 thing on the Western front, if anyone looks at the RAF's losses in 1941 (109F-era) and 1942 (190A-era), there's not much of a difference, if anything 1941 was worser for the RAF. The 190 fear factor was due to it's 'unknown' status, and the new tactics that came with it, after all the RAF's pilots had plenty of time to get used to the 109 and it's unfair, 'cowardly' diving attacks - using the strenghts of the plane.

As for the 190 go, the German opinion was rather different than the 'mythic adversary' British opinion. German documents from 1941-42 clearly show the 190 was certainly not seen as superior to the 109F performance wise, and it's engine had serious reliabilty problems for a while. The very reason the FW 190 largely replaced the 109 in France (in 1942, in 1943 the 109s numbers were greatly increased in France again) was that it was relatively peaceful front, where defensive flights were flown against skirmishing RAF planes thus a good place to try out a new aircraft with which there was little tactical experience, and flying over enemy territory was risky because of early engine problems.

Now we wonder... How does the Spitfire Mk.IX's (1942 version, Merlin 61, lacking rear-fuel tank) turning compare to the Spitfire Mk.V's (1941 version, Merlin 45, lacking rear fuel tank) turning? Similar, hundreds of feet apart? I often get confused since, in Aces High II, the Spitfire 9 turns quite worse than the Spit 8 according to tests, while, according to real-RAF tests, they turn the same.

I just can't seem to find info on the question. Remember, every upgrade takes away an old advantage...

lesofprimus said:

The Kurfurst did not have the agility portion of the performance review.... Speed yes, climbing yes, but it handled like a fat dog when compared to its contemporary enemies, the maneuverable Yak-3's/La-5 and 7s, and of course the Spits and Stangs...

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Well in a game perhaps but not in reality. The 109 K-4 would certainly be able to match the above in maneuverability at slow to medium speeds, even out-turning the Spitfire Mk.XIV. At slow to medium speeds the Bf-109 is a very agile little fighter.

The Mustang hasn't got a chance unless the speed and altitude stays high, it was a turkey compared to the Spit, 109, Yak La in terms of dogfighting.

X

Ok Chingachgook, I'll explain to you how things really are.

The Spitfire has a wing-loading advantage, sure, however its got a disadvantage in power-loading, drag and size - plus, as you mentioned, the 109 has slats which is a rather big advantage in a turn.

The slats increases the lift by 25% in the covered areas, and the critical AoA of the entire wing is increased as-well, allowing for a much tighter turn.

The Bf-109 has 48% of its wings covered by the slats, which means roughly a 12.5% increase in lift and still a 25% increase in available AoA.

Next comes drag, and this is where the Spitfire really looses out, as since the 109 is MUCH smaller than the Spitfire, its also much less draggy - having a very small flat plate area by comparison. (Ever wondered why the Bf-109 always is much faster than the Spitfire at the same power ??) But thats not all, cause besides its much smaller size, the 109 also features a higher Aspect Ratio wing, which means more lift and less drag pr. wing area. And the 109's Span-loading is lower as-well, which is important when considering induced drag in turns.

Then there's power, well the 109 has an advantage here as-well, having a lower power-loading - which is important to be able to sustain your turn.


Now if you don't believe any of the above then you can read about all of it in books or on certified websites about aerodynamics. And if you want to we can go on to discuss the aerodynamics of each airplane ??

As to pilot accounts:

Walter Wolfrum, German fighter ace. 137 victories.
"Unexperienced pilots hesitated to turn tight, bacause the plane shook violently when the slats deployed. I realised, though, that because of the slats the plane's stalling characteristics were much better than in comparable Allied planes that I got to fly. Even though you may doubt it, I knew the Bf109 could manouver better in turnfight than LaGG, Yak or even Spitfire."

Herbert Kaiser, German fighter ace. 68 victories.
"Personally, I met RAF over Dunkirk. During this battle not a single Spitfire or Hurricane turned tighter than my plane. I found that the Bf 109 E was faster, possessed a higher rate of climb, but was somewhat less manouverable than the RAF fighters. Nevertheless, during the campaign, no Spitfire or Hurricane ever turned inside my plane, and after the war the RAF admitted the loss of 450 Hurricanes and Spitfires during the Battle of France." In the desert there were only a few Spitfires, and we were afraid of those because of their reputation from the Battle of Britain. But after we shot a couple of them down, our confusion was gone."

Erwin Leykauf, German fighter pilot, 33 victories.
"During what was later called the 'Battle of Britain', we flew the Messerschmitt Bf109E. The essential difference from the Spitfire Mark I flown at that time by the RAF was that the Spitfire was less manoeuvrable in the rolling plane. With its shorter wings (2 metres less wingspan) and its square-tipped wings, the Bf 109 was more manoeuvrable and slightly faster. (It is of interest that the English later on clipped the wings of the Spitfire.)
For us, the more experienced pilots, real manoeuvring only started when the slats were out. For this reason it is possible to find pilots from that period (1940) who will tell you that the Spitfire turned better than the Bf 109. That is not true. I myself had many dogfights with Spitfires and I could always out-turn them. This is how I shot down six of them."

Pierre Clostermann, Spitfire pilot.
"I tried to fire on a '109' that I spotted in the chaos. Not possible, I couldn't get the correct angle. My plane juddered on the edge of a stall. It was comforting that the Spitfire turned better than the '109'! Certainly at high speed - but not at low speed."


And there's plenty more where that came from, so can we quit the continues postings of pilot accounts now ??

Oh and before you go on to posting any Allied after action reports, just know there are equally many, if not more, of the same in German.

X

Chingachgook said:

Uh that posting was from German TESTS not pilot account, and there are plenty of examples of 109s stalling out in turn fights.
Clostermann... well... he's French - do your really want to see the RAF accounts saying they out turned 109s to the point of stall?
You say that even the German test is wrong (against a pre-BofB spit1a with only 2 speed prop and no 12lbs boost - it still had "significantly smaller turning circles and turning times." ???

Wolfrum ...opinion

Kaiser ... again opinion - I don't see him saying that he stalled out an enemy (the true indication that the other pilot was doing all he could in a turn).

Leykauf ...opinon. How does he know that the Spits were pulling all the way to stall? He is contradicting his own LW tests - NOT VALID.

Now do you want to see the German combat reports that say they got out turned? (you could start with my sig...)

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The test/pilot account with the 109E is the one which is NOT VALID. First of all its an Emil, which is known to have issues with its slats (Hence why Günther Rall didn't like turning the 109), secondly (as already explained by Leykauf and Wolfrum), by 1940 many pilots never pushed beyond the deployment of the slats, hence the result of that test - And exactly the same applies to all British tests with the 109, as the British test pilots were convinced the airplane was about to stall as soon as the slats popped out, aborting the maneuver emmidiately.

But hey whats the use, you believe your game more than reality anyways...

X

The Russians tested turn times for aircraft. Their figures, all at 1,000m altitude:

109F4 - 19.6 - 20.5 secs (at 2900 kg)

109G2 - 22.6 (at 3235kg) 20 - 21.5 secs (at 3023kg)

109G4 - 21 secs (at 3027kg)

Spitfire Vb - 18.8 secs (at 2920kg)

Spitfire LF IX - 18.5 (at 3351kg)

The slats increases the lift by 25% in the covered areas, and the critical AoA of the entire wing is increased as-well, allowing for a much tighter turn.

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Slats have almost no effect on lift, their only real function is to increase critical aoa. They allow the 109 to pull higher coefficients of lift, but do not increase lift at a given cl.

The problem with that is induced drag is proportional to the square of the CL, so whilst the 109 can pull higher cl, it does so at the expense of far more drag than the Spitfire.

Quite simply, larger wings generate less induced drag.

The Bf-109 has 48% of its wings covered by the slats, which means roughly a 12.5% increase in lift and still a 25% increase in available AoA.

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No, it translates to an increase in critical AOA, nothing more. At a given AoA, slats do not increase lift.

The 109 can pull to higher AoA, possibly even generate enough lift to counteract the Spitfire's huge wing loading advantage, but it does so at the expense of enormous amounts of drag, which is why it can't turn as well as the Spitfire.

Now if you don't believe any of the above then you can read about all of it in books or on certified websites about aerodynamics. And if you want to we can go on to discuss the aerodynamics of each airplane ??

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Indeed, please do. I'd love to see the serious source on aerodynamics that says slats substantially increase lift at a given AoA. The claim was 25%, wasn't it?

Hop,

Stop trying to put words into my mouth, I never claimed the slats increase lift at any given AoA, however as the critical AoA is reached (Which it is emmidiately in a tight turn) they deploy, increasing the critical AoA and thereby lift. Now sure when the Bf-109 turns at its tightest, tighter than the Spitfire, its going to create more drag, thats logical - The tighter the turn, the more the drag. Drag is a biproduct of lift.

And as to your claim that the slats don't increase lift, well thats total bullsh*t Hop. The slats delay the onset of stall by increasing the critical AoA, and the higher the AoA the higher the lift - and thats very simple aerodynamics btw Hop.

And as to the increase in drag, well fortunately the 109 is very small and has a very low power-loading, so although the 109 suffers from more drag pr. area in a tight turn, tighter than the Spitfire, it makes up for that in power and small size.

Also your "big wing" theory is so very flawed. A big wing does not simply create less induced drag than a smaller one.

Soren, great technical information, as usual from your part.

Oh and about the Russian tests Hop, you forgot to mention that the 109G-2 was equipped with gun-pods.