109's kill ratio (all variants from B to K)

[Widewing]

Originally posted by GScholz

Seventhly, do you have any quotes from 109G10 and/or 109K4 pilots that say they felt the P-51D was superior?

See pages 292-293 in Caldwell's "JG-26". It seems that the G-10 was far better liked than the K-4, at least within this organization. The book explains why, but it does seem that all of the K-4s they received were fitted with gondolas, which appear to have been universally disliked. Also, there is a description of the K-4's evil handling at high altitude.

Let's not overlook the handling quirks of the P-51D either. From an expert on the topic (as told by P-51 ace Sid Woods):

"In contrast, the P-51, had far fewer compressibility problems at speeds normally encountered in combat, including dives from high altitude.  The D model was placarded at 300 mph IAS (539 mph TAS, Mach 0.81) at 35,000 ft. In a dive, the P-51 was such an aerodynamically clean design that it could quickly enter compressibility if the dive was continued (in reality, a pilot could, as a rule, catch any German plane before compressibility became a problem).  But, say, in an evasive dive to escape, as the P-51's speed in the dive increased, it started skidding beyond what the pilot could control (this could be a problem in a dive onto a much lower-flying plane or ground target--couldn't keep the plane tracking on the target if speed was too high).  As compressibility was entered, it would start rolling and pitching and the whole plane would begin to vibrate.  This began about Mach 0.72.  The pilot could maintain control to above Mach 0.80 (stateside tests said 0.83 (605 mph) was max safe speed--but structural damage to the aircraft would result). The P-51's quirk that could catch the uprepared service pilot by surprise was that as airspeed built up over 450 mph, the plane would start to get very nose heavy.  It needed to be trimmed tail heavy before the dive if speeds over 400 mph were anticipated.  However, in high speed dives, the plane's skidding changed to unintended snap rolls so violent that the pilot's head was slammed against the canopy.  Depending on how much fuel was in the fuselage tank, on pull-out stick force reversal could occur, a real thrill that could totally flummox a low-time service pilot diving earthward at close to 1,000 ft per second trying to escape a pursuer. The P-51 was a good dogfighter, positively stable under all flight routines.  A pilot didn't have to work hard to get it to the limits of its flight envelope (that is, he wasn't sweating heaving and pushing and pulling and kicking to get it to move its ass.)  

It was important to burn down fuel in the fuselage tank to avoid longitudenal instabillity. Cranking into a tight turn with too much go-juice in the tank would mean instant stick force reversal and the pilot had to brace himself to oppose the stick slamming backward into his solar plexus, and shove hard to prevent the turn from tightening till, if he was lucky, he entered a high speed stall, or, if unlucky, the wing ripped off. Turns above 250 mph IAS were the killers, because they resulted in g forces high enough to black out the pilot so that he couldn't oppose the stick reversal and the Mustang would, unattended, wind itself up into a wing-buster."


My regards,

Widewing

[GScholz]

Hmm ... are Niel and Nashwan naughty? Not good. Trickery is not acceptable in a serious debate. I very much like every plane in AH to be as accurate as possible, but falsities are uncalled for no matter how big an enthusiast you may be.

[Nashwan]

1.8ata was authorized from the very beginning, and 1.98ata was cleared already in 3rd (!!) edition of the DB 605DC manual, dated November 1944.

According to Butch2k, before he took the All About Warfare forum down, the 109K4 was tested at 1.8 ata by a single JG during Feb 45, and 1.8ata was then authorised. 1.98ata was then tested during March, before being authorised sometime during March. I seem to remember you claiming the manual "authorised" 1.98 ata, and Butch telling you he had copies of the documents saying otherwise.

Need I remind you that 190 manuals authorised 1.45 ata on the A3 and A4, but the planes were derated to 1.35 ata for a long time, or that 109G manuals quote 1.42ata, but that technical bulletins prohibit more than 1.3ata from June 42 until sometime in 1943?

Also, not even +81 HP gave 2000 HP in the Mustang, only 1940, and only up to a mere 500 ft, then power fell of due to insufficent superchargin.

My Merlin chart, which includes the V-1650-7, shows a shade over 2000hp at 4000ft, with ram.

[VO101_Isegrim]

Originally posted by F4UDOA

An aircraft with higher drag will take longer to accelerate than one with lower drag even with higher HP many times. Drag is a huge factor especially cdi. Your cruise drag of the 109 is what cost so much. Fact is the pony could do a fast cruise of 400MPH at altitude that the 109 could never match. This was due to high cdi which slows the 109's acceleration drastically.

I am sorry F4U, but this is again wishful thinking. The Mustang could do 400 mph cruise ? You know what, prove it. What model, what engine power ?

And even if your claims are true, I have to disappoint you : the K-4 could cruise for infinitive time for 400 mph (645kph). At dauerleistung the cruise speed is given as 645 km/h at 8400 m. That it can do without any time limit. For a 30 min duration, it could cruise at 670 km/h at 9000m.

That is, the K-4 could cruise faster than the P-51D`s highest maximum speed at that altitude...

Not competitive, eh ?

Besides, it`s quite clear that at low speeds circa where acceleration happens, powerloading is the deciding factor, as drag is low. The Mustang`s key to high maximum speed was not low drag in general, but low drag of the airframe at high speeds. Because of the laminar flow, drag increased less than with other designs.



Instead of pointing to your sources for the 109's ailerons why don't you post them?

Why would I need to ? I referred to them already. You on the other hand, without any reference, state that the 109`s ailerons were poor. You have to produce something in regards of that before anything else.

Until then, you have to accept what my reports say, that they were light and good.


Also your data you keep refering to is clearly marked in AHT as 10,175lbs P-51D for climb and climb times. In practical combat that airplane would weight less than 9,000lbs.

That`s nonsensical. Less than 9000 lbs would mean no ammuntion, and perhaps 1/4 fuel tank.


You insist at comparing the heaviest possible configuration to a light 109.

Sorry, that`s ridiculus. Both planes are at take off weight, the Mustang w/o it`s droptanks or rear tank.

Of course we could play with half-empty tanks, but this would increase the 109`s climb advantage even further, as a lighter plane would gain lot more from even a slight weight reduction.


[qoute]
Why don't you ask a surviving German pilot how he felt? [/QUOTE]

How he felt because he was outnumbered 10 to 1 despite having a better airplane ?

Why don`t you take HoHun`s advice, and confront your opinion with the hard facts : the K-4 was faster, turned and climbed better than the P-51 .

[GScholz]

Interesting. Evil handling at high alts? Were they related to the gondolas or were they the result of some other factor?

[GScholz]

Where is Butch2k anyways? What's he doing now? Could we maybe hijack him over here for a quick lesson?

[VO101_Isegrim]

Originally posted by Nashwan
According to Butch2k, before he took the All About Warfare forum down, the 109K4 was tested at 1.8 ata by a single JG during Feb 45, and 1.8ata was then authorised.

Unfortunetely, that holds no water with reality. Understandable, as you are recalling it all from memory, and of course in the way you would like it to be.

Like as usual, you refer to butch with false qoutes from him, taking advantage that the forums are down, and nobody can check if you are lying. Expect of course, I have the page saved on my HDD. Bad luck, Nashwan.

Again : 3rd edition of DB 605 D manual dated late 1944 states the use of 1.98 ata.


1.98ata was then tested during March, before being authorised sometime during March.

Repeating it won`t make less wrong.


I seem to remember you claiming the manual "authorised" 1.98 ata, and Butch telling you he had copies of the documents saying otherwise.

Again you memory cheats you. Or it doesn`t, and it`s the usual dishonesty.

It wasn`t me who told butch about what the DB 605 D manuals says, but Schwarze man. And he is not just claiming it, like you do this nonsense here, but he has the manual, and it says 1.98ata. And of course your statement about butch saying the document says otherwise is just an utter nonsense. He never said that.

A sidenote, SM is an actual mechanic, working on restored G-10 with the very same DB 605 D engine type... but you might know better than him, relying on your memory...and bias.


Need I remind you that 190 manuals authorised 1.45 ata on the A3 and A4, but the planes were derated to 1.35 ata for a long time, or that 109G manuals quote 1.42ata, but that technical bulletins prohibit more than 1.3ata from June 42 until sometime in 1943?

Apart from being completely irrevelant to the subject, every
sentence is factually wrong.

No 190 manual ever called for "1.45 ata".
No 109G-2 manual qoute 1.42ata, in fact they say that the engine was "not yet cleared for them", and 1.3 ata is the maximum until furhter notice.

Of course, like in the 1.98ata case, you never ever saw any of those manuals you refer to, you just simply make big sweeping statements.



My Merlin chart, which includes the V-1650-7, shows a shade over 2000hp at 4000ft, with ram.

And my one says :

V-1650-7

Combat conditions

3000 rpm, + 25 lbs/ sq. in. BHP at SL = 1940
Max power in "MS" gear = 1940 BHP at SL
Max power in "FS" gear = 1810 BHP at 12000 ft

It`s a written text, not an approx. chart.

[VO101_Isegrim]

Originally posted by GScholz
Interesting. Evil handling at high alts? Were they related to the gondolas or were they the result of some other factor?

Yes, in fact it`s possibly related to the added weight of gondolas. In the JG 26`s war diary, Caldwell notices that all K-4s assigned to JG 26 were equipped with cannon gondolas, and for this reason, pilots liked for the G-10 better for dogfighting, which didn`t have those.

[Widewing]

Originally posted by VO101_Isegrim
That`s nonsensical. Less than 9000 lbs would mean no ammuntion, and perhaps 1/4 fuel tank.

With full tanks (less the rear fuselage tank), full ammunition, oil, pilot and all standard equipment, a P-51D weighs in a 9,611 pounds. Burn off 1/2 of the fuel and its right at 9,000 pounds.

A 9,000 lb P-51D, making 2,000 hp at 80 in/Hg is going to be a very tough customer for any 109, be it the G-10 or the K-4.

My regards,

Widewing

[VO101_Isegrim]

Originally posted by GScholz
What was the drag coefficient of the 109K4 and the P-51D (operational, not test dragster)?

I had a very interesting conversation about that a long time ago with Hans109. He had some polars and other drag docs for 109G, which also listed some later aerodynamic changes and drag values. From that, he could calculate the drag and drag coefficient for the K-4 in sustained climb. According to him, the K-4`s Cd0 as 0.0185 to 0.0190, for a flat plate area of 0.294 m2. The G-6`s Cd0 was 0.023.

As I recal the P-51`s Cd0 was something like .0173 or so, and varied quite a bit with surface finish quality. As since these coefficients are related to wing area, this would give the P-51 slightly more drag than the K-4.

[GScholz]

10,208 lbs fully loaded with 269 gallons of fuel

- 510 lbs for the 85 gallon fuselage tank

= 9698 lbs.

698 lbs is approx. 116 gallons

At 9000 lbs the P-51D would have approx 68 gallons left, which is almost exactly 1/4 of max internal capacity of 269 gallons. Isegrim's guessimate was pretty damn accurate.

EDIT: That's actually a good deal less than a full 109 tank.

[VO101_Isegrim]

Originally posted by Widewing
With full tanks (less the rear fuselage tank), full ammunition, oil, pilot and all standard equipment, a P-51D weighs in a 9,611 pounds. Burn off 1/2 of the fuel and its right at 9,000 pounds.

A detailed loading plan would be most welcome to show this.

A 9,000 lb P-51D, making 2,000 hp at 80 in/Hg is going to be a very tough customer for any 109, be it the G-10 or the K-4. [/B]

It would be as fast at low alts. Real test showed 379 mph for the P-51 D at 80 Hgmm, vs. 377 mph of the K-4. No real difference.
Because of the desing of the supercharger, the K-4 would still hold it`s speed advantage in the Merlin`s power drop zone, and high altitude performance would remain the same, favouring the K-4 again.

In climb however, I don`t that with any trick the P-51 could compete with a K-4, especially if the latter also only lightly loaded.

[Widewing]

Originally posted by VO101_Isegrim

As I recal the P-51`s Cd0 was something like .0173 or so, and varied quite a bit with surface finish quality. As since these coefficients are related to wing area, this would give the P-51 slightly more drag than the K-4.

I believe .0173 represents the P-51B/C.

It's a bit higher for the P-51D at .0176.

My regards,

Widewing

[Nashwan]

Hmm ... are Niel and Nashwan naughty? Not good. Trickery is not acceptable in a serious debate. I very much like every plane in AH to be as accurate as possible, but falsities are uncalled for no matter how big an enthusiast you may be.

A word of warning about Isegrim. If you disagree with him, he's apt to call you a paedophile. He has a rather strange relationship with the truth. I know this for a fact, because he attempted to prove I was a liar by posting "quotes" from me that I hadn't made, or had made in a different context.

GSholz, if you have any doubts about the information I have posted, ask and I shall attempt to back it up.

As to Isegrim's allegations:

"Just to make clear, Nashwan often makes up ridiculus things, like +25lbs being standard on Spit XIVs,"

Isegrim likes  to use the best figure he can find for anything German, no matter what the context.As such, I am comparing like for like. There is a source showing Spit XIV speeds that can only be achieved at 25lbs boost, so I am using it until I see evidence otherwise. http://www.fourthfightergroup.com/eagles/spit14pt.html

or nonexistent "ghost" Spitfire XIV squadrons which are supposed to serve in India during WW2,

You could look up the career of "Ginger" Lacey, who commanded a squadron re-equipped with Spit XIVs in India during the war. If the story goes into enough detail, you will see that he was originally allocated Spit XIVs with bublle canopies, which he rejected, and were passed to another squadron in India.

or funny theories for the Murmansk convoys

The "funny theory" about the Mrmansk convoys is that they were also used as bait to lure out the Tirpitz. The dispute with Isegrim started over PQ17, which I said was being used as bait. Isegrim maintains the covering force for PQ17, which included 1 British an 1 US battleship, a carrier, and many cruiser, ran away as soon as they heard Tirpitz was out. He's taken my comment that the convoys were used as bait to mean they were ONLY bait, and had no other purpose.

1.8ata was authorized from the very beginning, and 1.98ata was cleared already in 3rd (!!) edition of the DB 605DC manual, dated November 1944.

This is directly contradicted by Butch2k. I don't know if you ever went to his board, but it was a good place to discuss WW2 aircraft. Butch occasionally posts here, I hope he is still reading these forums. I believe he is researching a book on the 109, and most of Isegrim's 109 information comes from Butch, including the original documents that he quotes in his speed and climb graphs.

Butch was adamant that 1.8 ata wasn't authorised until Feb45, 1.98 ata until March 45.

Just to make clear, Nashwan has again no idea of what he is talking about. First, not all Mustangs switched to 150 grade.

I never said all. I said 8th AF Mustangs did, and British home based Mustangs did.

I don't know for certain that every 8th AF Mustang switched, but I did give you the figures for 8th AF 150 octane consumption, 20,000 tons per month, which is a very large number of fighter sorties. (700 a day assuming 1 ton of fuel used per fighter)

Second, he "forgots" to mention that the 8th AAF used only 71" Hg with their Mustangs, instead of 67", when running on 150 octane.

I didn't "forget" anything.

To quote myself:

According to the manual, 25lbs boost was limited to 5 mins, same as 18 lbs boost (Note the US didn't allow 25 lbs at all, something like 76 " HG, 21 or 22 lbs boost iirc).

The 71" figure Isegrim quotes sounds too low to me. I believe the 8th used 72" in the V-1650-3. They may have used the same figure in the -7, but I wouldn't be suprised if they used more. I can't track down a source with the exact figure at the moment.


Doing the conversion now, my figure of 21 or 22 lbs boost equals 73 or 75" HG, which isn't far off given my "iirc"

Also, not even +81 HP gave 2000 HP in the Mustang, only 1940, and only up to a mere 500 ft, then power fell of due to insufficent superchargin

Isegrim is deliberately distorting again. He likes to give sea level only HP figures, no matter what altitude is being discussed. His 500 ft figure is correct only for low speed, not high speed flight, where ram air assists the supercharger. The figures from the Merlin chart  have are about 1940 at 0ft 400mph, to about 2040 at 4,000ft 400mph. If you want proof, I can arrange to send you the chart.

[VO101_Isegrim]

Originally posted by GScholz
10,208 lbs fully loaded with 269 gallons of fuel

- 510 lbs for the 85 gallon fuselage tank

= 9698 lbs.

698 lbs is approx. 116 gallons

At 9000 lbs the P-51D would have approx 68 gallons left, which is almost exactly 1/4 of max internal capacity of 269 gallons. Isegrim's guessimate was pretty damn accurate.

EDIT: That's actually a good deal less than a full 109 tank.

Thanks. I believe these are US gallons, right ? That would give around 50 imp. gallons. Now, since we are asking for 150 grade and increased boost, we should also take increased consuption into account. The Merlin on these extreme boosts was a fuel hog, the SpitIX test show no less than 197 gall/hour consumetion at +25 lbs. That would mean that our low weight, high boost Mustang would actually consume half of it`s fuel capacity in about 5 minutes when running on maximum boost... how would it go home ? Gliding ?