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

[VO101_Isegrim]

Originally posted by Nashwan
Hardly rare. I believe the majority of British Mustangs were Mustang IIIs with -7 engines. But it's besides the point.


Your argument was that the "Mustang" yielded more speed per power. Your example for that was Mustang III with V-1650-7 at high boost. Apart from the boost issues, it`s fairly evident that one cannot say that every Mustang was more effiecient when it`s only true to the the Mustang III series, and, speaking in absolute numbers, even most of those MkIIIs were not capable to achieve similiar speed, being more efficient or not.

To remind you :

Most "Mustangs" were Mk IVs, not Mk IIIs. So, if anything is a representative example of a "Mustang" airframe effiency, it should be from the numerous Mark IVs, not from the rarer Mark IIIs.


The point that I was replying to was how the speed of the Mustang compared with similar power to the 109. It wouldn't matter if this was the only Mustang that ever ran at this power to work out comparitive efficency.

It wouldn`t if you would have picked a standard "Mustang" airframe to show this. But what you picked was a stripped V-1 chaser from the faster III series (which were far less numerous than MkIVs / Ds), and based on that, you claimed that the Mustang (and that means in your context, that every Mustang - A, B, C, D types) were more efficient in turning power into speed.

Obviously, you choosed the faster, less common variant to show that all Mustang airframes had better effiency.
Which only stands for the Mk IIIs, but not to the slower, but much more common Mk IVs. In other words, a smaller series of Mustangs had better effiency in turning power into speed, while most of them were equal at best in that regard to the 109K series.


Isegrim, what are the details of the 109K4 speed tests? How many aircraft, what condition, corrected for temperature etc?

I don`t have the full documentation. However, it refers to full takeoff weight, unlike British tests, which all seem to show level speed at only 95% takeoff weight, or roughly at half fuel load.

Now, can we see the page that deals with the Mk III`s properties in your test ?


Can we have some details on this test? Condition of aircraft, what was fitted, wether the results were corrected for standard atmosphere etc?

See below. BTW, since it`s a British test on the MK IV, corrections, weight etc. should be the very same as on your V-1 chaser. Note, I haven`t seen any documentation regarding the condition of your V-1 chaser, expect your description of it. Personally, I doubt you have much information on it, expect you saw it on Mike`s Ultra Selective Test Site, and liked the performance figures claimed for it.


So a Mustang, in unkown condition, taken from an operational squadron, was the same speed as the factory data for the 109K4?

The condititions of it are maybe unknown to you, like in the case of the V-1 chaser, but that doesn`t mean it isn`t stated in the report.

Indeed, the most numorous, most common Mustang IV airframe on similiar power as the K-4 airframe achieved similiar speeds.


Once again, Isegrim, you trying to compare different standards. Factory figures for the 109, aircraft pulled from squadron in unknown condition for the Mustang.

The Mustang`s condition is not unknown, as I already mentioned it, though I understand you have to neglect it in some way as it`s very unfavourable to your statements.

Here are again :

AAEE Boscombe Down.
Mustang IV T.K 589 (Packard MerlinV.1650-7)
Posistion error of static vent and brief level speed trials.
July 1944.
Aircraft flown with faired bomb racks.

Speed at 0 ft using 67"hg 354mph
Speed at 0ft using 81"hg 379mph

Also the full report mentions the plane was bare metal, so it would be pretty hard to except the paintwork being in poor condition...

BTW, I did not notice you would have problems about conditions when Neil posted this very data.

And we know the K-4 did 593 km/h (368mph) at 1.8ata/1850PS, and 377 mph at 1.98ata/2000 PS at 3400kg.

So what we have is an official figures at known and similiar powers for a Mustang at 95% takeoff weight (also w/o rear tank), and a K-4 at 100+% TO weight, and the K-4 seems to get the very same speed as the Mustang... so it`s hardly a case about the P-51D`s superior drag design, since we have equal speeds achieved at equal powers and roughly equal thrust available.

[gripen]

Isegrim,
Do you happen to know any real test flight performance data on Bf 109K?


gripen

[MiloMorai]

Originally posted by gripen
Isegrim,
Do you happen to know any real test flight performance data on Bf 109K?
gripen

Good request gripen, but will get some 'song and dance' for not suppying .

We all know that German a/c were perfection, could win a concours d'eligance. Considering the 'fit and finish' of late war German a/c, assembled by 'slave labour', the results sound like factory calculated numbers.

The P-51D/K (Mustang IV) was less than 5mph (0.75kph) slower than the P-51B/C (Mustang III). Ise is 'barking at shadows'.

[Nashwan]

It wouldn`t if you would have picked a standard "Mustang" airframe to show this. But what you picked was a stripped V-1 chaser from the faster III series (which were far less numerous than MkIVs / Ds),

I "picked" what data is available. There's a test of the Mustang III giving details of testing conditions and conditions of the aircraft. I haven't seen any other Mustang tests at around 2000hp that give those details. If you can furnish me with the details you claim to have, I will glady use iother tests results.

and based on that, you claimed that the Mustang (and that means in your context, that every Mustang - A, B, C, D types)

Not at all. If you notice, I say what model of Mustang it was in the tests. Can I take it that your graph of the 109K4 speed means "in your context" that every 109 - b c d e f g and k types - were that fast?

Obviously, you choosed the faster, less common variant to show that all Mustang airframes had better effiency.

That's right, I went back to 1944 and carried out the test myself.

I don`t have the full documentation.

You don't? Yet you want to rule out comparison with a cleaned up Mustang, and only compare with a Mustang taken from squadron service. How strange.

Isegrim, answer honestly, what condition do you think the 109 in your graphs was in? What is the original source of the graphs?

Now, can we see the page that deals with the Mk III`s properties in your test ?

I have quoted almost every word to you, and given detailed descriptions of what was done to the aircraft. I am unable to post the pictures. Can we see the tests of the 109 you are reffering to when you claim 378 mph?

See below. BTW, since it`s a British test on the MK IV, corrections, weight etc. should be the very same as on your V-1 chaser

"Should be" doesn't cut it. Not every test the A&AEE, let alone the other establishments, carried out was a full test, with all the rigmarole that goes with them. The very fact it says "brief speed trials" indicates that was not the purpose of the test.

The condititions of it are maybe unknown to you, like in the case of the V-1 chaser,

The conditions of the V-1 chaser are known, and I've already posted them. Why do you think I put quotation marks around descriptions of the paintwork, like "very poor condition"  or gave exact details like "6 coats of badly chipped paint"?

Indeed, the most numorous, most common Mustang IV airframe on similiar power as the K-4 airframe achieved similiar speeds.

You've already said those Mustang figures are for an aircraft taken from squadron service, and admitted you don't know the K4 condition.

Now, a Mustang III where we do know the condition managed 395 mph with bomb racks, small bracket, and cleaned up paintwork. We also know that the P-51D was slightly slower. Note, however, that it would need to be 17mph slower to match the figures you are touting as being representitive for the D series. I've never seen anything to suggest the D was that much slower.

BTW, did the 109K4 that you are quoting at 378 mph have bomb racks? What about gondolas? After all, if we're including bomb racks on the Mustang because most had them...

The Mustang`s condition is not unknown, as I already mentioned it, though I understand you have to neglect it in some way as it`s very unfavourable to your statements.

Here are again :

AAEE Boscombe Down.
Mustang IV T.K 589 (Packard MerlinV.1650-7)
Posistion error of static vent and brief level speed trials.
July 1944.
Aircraft flown with faired bomb racks.

Speed at 0 ft using 67"hg 354mph
Speed at 0ft using 81"hg 379mph

That says nothing about the condition of the plane other than it had bomb racks. You have also said it was unpainted. What else?

Also the full report mentions the plane was bare metal, so it would be pretty hard to except the paintwork being in poor condition...

So you have the report? Can we see it please, or could you at least quote the description of the Mustang.

It certainly couldn't have had poor quality paintwork, but what condition was the metalwork in?

BTW, I did not notice you would have problems about conditions when Neil posted this very data.

I'm not aware I saw it. Which isn't to say I didn't see it, just I don't recall, and probably didn't pay much attention to it at the time.

So what we have is an official figures at known and similiar powers for a Mustang at 95% takeoff weight (also w/o rear tank), and a K-4 at 100+% TO weight, and the K-4 seems to get the very same speed as the Mustang

Well, what we seem to know is the speeds of two aircraft, but not the conditions they were tested in, wether the tests are corrected for weather conditions, and even wether the 109 figures are tests or calculations, or a mixture of both. I suspect that as Butch said they were calculations based on tests (iirc) the 109 figures refer to a manufacturers prototype, which is not to say it wasn't to final specifications as regards weight, equipment etc, but it was probably better quality than average production, let alone than the average machine taken from squadron service.

[niklas]

Bozon, the gradient of prop efficiency is usually much steeper close to 600km/h than at 500km/h, if you want to have an aircraft with reasonable climb and acceleration. Then there exist other drag effects that canīt be described by v^2, but which begin to show up at ~550km/h. Then there is the effect of Reynolds number and so on. Prop running at higher Mach number. Itīs way harder to come from 570 to 610, definitly.

Anyway, there donīt exist official german claims for a K to perform over 600km/h at sealevel on a regular basis. Thatīs the point. Individual machines may have performed better, like allied individual machines did perform in an impressive way. Still waiting to see official performance claims for the P-51. From the B i know it was 425mph at altiude.

The Schwarz company, manufactoring company of wooden propellers in germany, evaluated the propeller of a P-51. Letīs see if i can get out the design speed of the prop. Is Wells still hanging around? I think he could help me. Btw, the prop was unusual for the time. Completly laminar design on BOTH sides (for manufactoring reasons the bottom side was often rather flat).
You see, there are maybe other reasons than a cooler design that was based on 30 years old, pretty common ideas.

Just another note: I already wrote that the factory surface quality of a P-51 was superior to the 109 oneīs. So the 109 could be improved much more by careful work done by the mechanics.

niklas

[Angus]

Hey, Isegrim, You're nuts....or you have Alzheimer.
Remember the base factors of flight, Thrust, Drag, Lift, and WEIGHT!
Once again, well to quote you:

"So what we have is an official figures at known and similiar powers for a Mustang at 95% takeoff weight (also w/o rear tank), and a K-4 at 100+% TO weight, and the K-4 seems to get the very same speed as the Mustang... so it`s hardly a case about the P-51D`s superior drag design, since we have equal speeds achieved at equal powers and roughly equal thrust available."

What is the Mustangs Weight? 95% (ONLY)of WHAT? Would it not happen that the Mustang is roughly 2000 lbs heavier? If you mention aerodynamical efficiency, you must not leave out the weight!
Unless it suits your thesis. Which would be what?

[Nod]

i like pizza

[Ike 2K#]

Guys i've been M.I.A. (missing-in-action) in this thread. Are you guys saying that Bf-109G-10 and K-4 is similar to specs?

[VO101_Isegrim]

Originally posted by Ike 2K#
Guys i've been M.I.A. (missing-in-action) in this thread. Are you guys saying that Bf-109G-10 and K-4 is similar to specs?

No, G-10 should be some 20 km/h slower than the K-4 (at same engine ratings), but at the same time, it should climb a little bit better.

[VO101_Isegrim]

Conditions of Mustang IV TK 589

"Condition of aircraft relevant to test

2.1 General.

The following were the chief external features :

Six .50 machine guns in the wings, ports and ejector chutes sealed with fabric.
Camera gun port in port wing, sealed with fabric.
Multi-ejector exhaust manifolds with shroud plates.
Air intake in nose with internal ice-guard.
Aerial mast without external aerials
Bead sight in front of windscreen.
Air filter intake in lower left cowling
Faired bomb racks under wings.

The aircraft was not painted. The under surface of the wings back to the main spar and whole top surface had been coated with smooth compositon, the joints being filled and the remainder being bare metal. The fusalge was left with bare metal except for a matt anti-glare finish on the top of the engine cowling. All other parts of the aircraft were also bare metal, except the elevator and rudder which were fabric covered and doped.

In order to obtain adquate cooling, level speeds were done with the radiatos exit duct flap set to a gap of 8 1/2 inches, as coolant temperatures were excessively high with the normal setting of 7 1/2" gap.

Loading.

The tests were done at a take off weight of 9480 lb, with a C. of G. at 100.2 ins aft of the reference axis. This correspondd to a typical loading with no fuel in the aux. fuselage tank and no external tanks or bombs.

[NOTE : level speeds refer to 9000 lbs, or 95% of the T-O weight as usual.]

Looks like this Mustang received some nice care, ie. gun ports, ejectors etc. were sealed with fabric,joints were filled, paintwork was non-present, and was coated with a smooth composition on most of the wing. Briefly, much better what an operational Mustang may receive.

The test also describes the various corrections done for propellor tip Mach numbers, air temperaturs, etc., the usual stuff. Noteworthy that pressure head static vent combination was used instead of a simple pitot-static head.

Speeds measured at SL:

MS gear, 3000 RPM. Radiator flap adjusted to give 8.5" gap. Corrected to 9000 lb[=95% T-O weight]

+18 lbs : 354 mph. Equals 1630 BHP
+25 lbs : 379 mph. Equals 1940 BHP

Compare to :

K-4, 3400 kg, at SL :

1.8 ata : 368 mph. Equals ~ 1805 BHP
1.98 ata : 377 mph. Equals ~ 1950 BHP

Normal takeoff weight of K-4 was given as 3362 kg.

[VO101_Isegrim]

Originally posted by gripen
Isegrim,
Do you happen to know any real test flight performance data on Bf 109K?

gripen

Gripen, I have the ones from these series :



I don`t have all of them, however based on the date, I belive they might refer to Werk 330 130, which was tested at those time at the Messerscmitt Werke. It seems to me that these show calculations for the expected performance for K-4 and K-6 with the new type propellor, and also have a comparison data for test flight of normal K-4 with the serial propellor, on which probably the calculations were based, using propellor effiency. Do you have the full version of these papers ?

[gripen]

Isegrim,
I have that on microfilm (Obb. Forschnungsanstalt, Oberammergau, 19.1.1945). Nothing in that frame indicates that it's flight tested data (data points or something, weight claim actually speaks for calculation). Other frames on same data set give some engine numbers which appear to refer different engine versions (9-605-2290 and 91, 1.8ata or 1,98ata) and propeller blade versions. Other frames on same set don't either contain any indication if it's a flight tested data.

BTW smooth finnish on wing surfaces was a standard feature on all Mustangs.

gripen

[VO101_Isegrim]

Originally posted by Nashwan

Not at all. If you notice, I say what model of Mustang it was in the tests. Can I take it that your graph of the 109K4 speed means "in your context" that every 109 - b c d e f g and k types - were that fast?

How can a graph titled for K-4 refer to other versions as well ? I cannot imagine.



You don't? Yet you want to rule out comparison with a cleaned up Mustang, and only compare with a Mustang taken from squadron service. How strange.

How could I rule out comparision with a cleaned up Mustang ? The Mustang IV I showed was in very good condtion.


Isegrim, answer honestly, what condition do you think the 109 in your graphs was in? What is the original source of the graphs?

Full takeoff weight, standard propellor, and "clean" machine probably, ie. the one that one should expect to meet in a dogfight.


"Should be" doesn't cut it. Not every test the A&AEE, let alone the other establishments, carried out was a full test, with all the rigmarole that goes with them. The very fact it says "brief speed trials" indicates that was not the purpose of the test.

See above.


Now, a Mustang III where we do know the condition managed 395 mph with bomb racks, small bracket, and cleaned up paintwork.


No sorry. I checked your figures vs. that of Neil`s and they don`t match what I have got. You made several significant mistakes.

You qouted the meausured speed of the Mustang III at 395mph, but that it only achieved at 3900 ft (given as 391 mph in 6/10 618).

Sea level speed for in the August 1944 test in AVIA 6/10618 for Mustang III FB 377 w, Wing racks fitted, +25Lbs boost is given as 383mph at 0ft, and  391mph at 3900ft.

Neil also said the the Mustang was in same condition as the Tempest, ie. "fairly poor", and not "very poor".

He qoutes the following gains :

8mph due to the removal of bomb racks.
1mph due to removal of aerial bracket.
12mph due to improved finish.

So basically the 395 mph figure is a Mustang III w/o bombracks, w/o aerial brackets, and with improved finish.

In good finish, this Mustang did 383 mph w. the usual bombracks, and 391 mph w/o them.


We  also know that the P-51D was slightly slower. Note, however, that it would need to be 17mph slower to match the figures you are touting as being representitive for the D series. I've never seen anything to suggest the D was that much slower.

It wasn`t that much slower, see above. It was about 4 mph slower than P-51B/C.

BTW, did the 109K4 that you are quoting at 378 mph have bomb racks? What about gondolas? After all, if we're including bomb racks on the Mustang because most had them...

I don`t know about bomb racks, 109s didn`t carry them anyway as standard like Mustangs did. They could be present though, as the K-4`s weight is given as some 40 kg heavier than normal TO weight. As for the effect of racks, there were two types, one for a drop tank and the other specially for bombs, and I don`t have speed loss for neither. I have them for gondolas though, they come with -8 kph (-5mph) penalty. In any case, they were optional fitting Ruestsatze, and as a matter of fact, I never seen any K-4 picture with those.


I suspect that as Butch said they were calculations based on tests (iirc) the 109 figures refer to a manufacturers prototype, which is not to say it wasn't to final specifications as regards weight, equipment etc, but it was probably better quality than average production, let alone than the average machine taken from squadron service.

Except that the officially given for K-4 is 3362kg, whereas the test machine is given as 3400 kg, so it has all equipment and possibly more. The test paper is also dated January 1945, when the K-4 was already in service for some 4 months, so it`s hardly a prototype. Most likely these are calculations for a new "Dunnblatt" proplellor type, and tests for the old propellor plane is given as reference as in other tests, ie. the ones which were done with Jumo 213 fitted to 109s, which contain G-5 figures.

[HoHun]

Hi Gripen,

>Obb. Forschnungsanstalt, Oberammergau

Do you happen know what kind of institution this was?

All I learned from Google was that it was secret :-)

Other than that, I'm not sure what to think of this link:

http://www.the-wolery.demon.co.uk/briscon/back2.htm

Regards,

Henning (HoHun)

[gripen]

HoHun,
Obb. Forschnungsanstalt, Oberammergau appears on late German docs, no idea what it exactly was or what they exactly did. Anyway, many organizations were relocated to countryside or where ever to avoid bombing.

Isegrim,
I repeat, nothing on these frames indicate that the data presented is based on flight tests, actually weights and shape of the curves indicate that these are calculations. Seems that you just wan't to use the best data you can find on the Bf 109 and worst you can find on the Mustang.

One person once said here that the wildest performance claims on these boards come for planes which have most controversial history.

gripen