Favorite fighter/interceptor?

[Soren]

Bill,

I don't buy Caldwells words on this subject as so many actual FW190 pilots tell quite a different story, also his claim that the Dora didn't turn as-well just quite simply doesn't hold water at all, not only because EVERY SINGLE FW190 vet says otherwise, but mostly because it doesn't fit into the basic laws of physics.

Read Dietmar Hermann's book on the 'Longnose', in it there are many German reports on the merits of the Dora over the Anton, namely the much better turn performance (More power & less drag has this effect) & climb rate, and esp. the much better high alt performance. And finally the comparative tests ended with the very same conclusions, the Dora-9 turns much better & climbs much better at all altitudes.

Also in Willi Reschke's (FW190 & Ta-152 pilot ace) book Wilde Sau he explains how the Dora's were causing problems for the P-51's, giving them a fight to the teeth at high alt. However the big advantage in numbers the P-51's enjoyed at that point was enough to ensure that the Dora's were almost always in a disadvantagous situation, nomatter what they did really. Teamwork beats individual performance. They were fighting a lost battle against so many.

[B-17engineer]

Shiden

[drgondog]

Originally Posted by Soren

Bill,

I don't buy Caldwells words on this subject as so many actual FW190 pilots tell quite a different story, also his claim that the Dora didn't turn as-well just quite simply doesn't hold water at all, not only because EVERY SINGLE FW190 vet says otherwise, but mostly because it doesn't fit into the basic laws of physics.

Read Dietmar Hermann's book on the 'Longnose', in it there are many German reports on the merits of the Dora over the Anton, namely the much better turn performance (More power & less drag has this effect) & climb rate, and esp. the much better high alt performance. And finally the comparative tests ended with the very same conclusions, the Dora-9 turns much better & climbs much better at all altitudes.

Also in Willi Reschke's (FW190 & Ta-152 pilot ace) book Wilde Sau he explains how the Dora's were causing problems for the P-51's, giving them a fight to the teeth at high alt. However the big advantage in numbers the P-51's enjoyed at that point was enough to ensure that the Dora's were almost always in a disadvantagous situation, nomatter what they did really. Teamwork beats individual performance. They were fighting a lost battle against so many.

It's ok Soren. Recounts, anecdotally, are subjective in both directions. But Caldwell didn't claim' the comparison, merely reproduced the December JG26, III./JG54 diaries of the period.

[renrich]

Bill, enjoyed your post of the flight tests on the FW190D9. Sounds like when all systems worked properly and the AC was properly prepared the "Dora" was an honest 400 mph fighter. Interestingly the data in my reference "The Great Book of WW2 Airplanes," on the D9 must have been taken directly from the flight test you posted. Makes me have more confidence in the data in the book. Thanks.

[Soren]

Apparently the guys who actually flew the bird as-well as physics takes a back seat according to you Bill ? Very illogical IMO.

Renrich, try with 440 mph

[drgondog]

Originally Posted by Soren

Apparently the guys who actually flew the bird as-well as physics takes a back seat according to you Bill ? Very illogical IMO.

Renrich, try with 440 mph

How did you read that in my comment?

You said, IIRC, that Caldwell (and Caldwell's recount) was BS - or words to that affect. I pointed out that he merely reproduced JG26 and III./JG54 pilots diary notations. There has been a long period since he published both JG26 and the War Diaries of JG26 and no one I have heard of were outraged with the comments except perhaps you? I will ask Don what, if any comments he received from surviving Dora pilots - maybe there has been some.

Having said that, how does that imply that my words over ride pilots that flew it, when I thought I pointed out written accounts from pilots that flew it?

Are you saying that Caldwell is predjudiced toward the USAAF and favors US in his books - if so read them again.

Last - I pointed you to the series of G.m.b.h Bremen reports conducted at Bad Eilsen and asked your opinion of them with no response. They show very nice performance for various engines, boost and conditions - nothing to indicate that the Dora was not an exceptional machine so they shouldn't be considered a distortion unless you have unimpeachable data from another source.

These reports were apparently extracted with Dietmar Hermann's permission. Are these reports in your opinion, not representative of the facts (or physics) of the Fw 190D-9 flight tests or operational comments? Here are some of the comments from the report, including the Max theoretical performance at 432mph at 18,000 feet with engine gaps sealed and uncorrected airspeed for compressibility and without ETC.

The Best SL performance was with B4 and MW50 at 2.02 ata, without ETC and with engine gaps sealed (theoretical, no evidence of 2.02ata ever being attained in field, no ethenol used in field - only water, no production version delivered with engine gaps sealed) was 387mph from the chart... and 367mph w/o engine sealing and with ETC504 and variable wheel covering.

These are great numbers but also closer to theoretical because of lack of ethanol, engine gap seal, 2.02 ata cpability in field for the 190Dora with the D-9 prop at 3250 rpm at max WIP/TO engine conditions... at full ammo and 141 gallons of fuel for gross weight of 9590 pounds

The following chart depicts level speed performance as calculated by Focke-Wulf along with the results presented in Report 3 of Wk Nr. 210002. The report is carefull to note the theoretical data is derived from wind tunnel drag tests in which the scale model was perfectly smooth (hence engine seal in flight test to closer approximate the wind tunnel conditions for drag)

FW 190 D-9 Flight Trials (scroll down about 2/3)


The condition representative of standard production Fw 190 D-9’s during 1945 is as follows: Jumo 213A operating at 1.8 ata with B4 fuel & MW 50, equipped with ETC 504, main wheel fairing doors absent/fixed and engine gap not sealed. Of all the data charted in the compilation curve linked above, that curve best fitting the condition of a standard production Fw 190 D-9 is curve 4 of the Focke-Wulf Fw 190 D-9 chart dated 11.3.45 (the red line). One shortcoming of this curve, when viewed in context with other curves from Focke Wulf’s Flugmechanik Department, is that it assumes the installation of the engine gap seal and is therefore approximately 13 km/h optimistic relative to the condition of delivered production aircraft (with rack minus the drop tank).

I would have to check but I believe the actual max for the above conditions was 367mph at SL and max climb at 3329fpm at SL with a top speed of 413mph around 21,600 feet?

Dietmar Hermann summarized FW 190 D-9 performance as follows:

I haven’t read or heard that the D-9 was tested with the Jumo 213 and C3 fuel. I know that at the beginning of development Focke-Wulf made a distinction between the normal Jumo 213 and the Jumo 213 with 100 octane fuel. I think that there was not a problem with the engine; rather there was a problem of the fuel’s availability. In my book I have published one chart from 3.1.45 (page 154) showing FW 190 D-9 performance with B4 fuel with MW 50 injection operating at 2,02 ata (Sondernotleistung ). However, I have no evidence showing that 2,02 ata was enabled by the end of the war. I think that the D-9 was flown either with the 1900 PS update or with MW50 injection (2100 PS).

Help me out on the 'physics' dispute regarding the Dora - I am not aware that anything I said challenged any principles of physics or aerodynamics, but who knows?

[Soren]

Bill,

I'm making sure I know what you mean that's all.

The tests presented on Mike Williams site were carried out with a underperforming batch of engines, hence the results. Lutz notes this on William's site as-well. Sorry for not addressing this earlier, guess I thought I already had.

As to the physics, again they dispute what Caldwell claims. But tell me what effect does an increase in power with a decrease in drag and no change in weight normally have on an a/c's performance? I understand you have a good understanding on aerodynamics so this should be easy really.

Finally let me point out that it is Caldwell's claim I don't believe.

[drgondog]

Originally Posted by Soren

Bill,

I'm making sure I know what you mean that's all.

The tests presented on Mike Williams site were carried out with a underperforming batch of engines, hence the results. Lutz notes this on William's site as-well. Sorry for not addressing this earlier, guess I thought I already had.

As to the physics, again they dispute what Caldwell claims. But tell me what effect does an increase in power with a decrease in drag and no change in weight normally have on an a/c's performance? I understand you have a good understanding on aerodynamics so this should be easy really.

Finally let me point out that it is Caldwell's claim I don't believe.

Soren - the comments about the underperforming engines are made by Hermann in this report... which is why I went to the discussion regarding 2.02 ata and best theoretical results based on wind tunnel drag numbers.

As you noted, I DO understand the physics of increased power even with same drag (no evidence of 'decreased drag other than artificially covering engine gaps and wheel covers - neither of which would exist in the field).

You seem to be sliding into old habits of sarcasm?

I also understand that calculated results are rarely attained in flight test because wind tunnel models are exceptionally clean in contrast to operations... ditto engine performance from one airplane to another which is why aircraft are generally picked at random - at least in USAAF and USAF tests.

So Hermann points out that the properly performing Jumo 213A would yield 70-100 hp more than the October 1944 test results - but would NOT attain the best 'theoretical' results which uses all the optimal factors never achieved by a production Fw 190D-9 according to him (and the caveats I cited in the above thread). He also pointed out that the -12 propeller seemed to boost the performance over the -9 prop.

Back to Caldwell as you didn't seem to finish your thoughts on him. I didn't read that as 'his words', but as a reproduction of a diary compiled by III./JG54 pilots recounting their experiences with the D-9 in December-January operations.

In other words Caldwell was not 'claiming' anything, just presenting other's words. You may have a more complete source to references which refutes the operational observations of those pilots. I haven't seen such but doesn't mean they don't exist.

Back to Mike Williams reproductions of Hermann's reports and comments - Is Hermann incorrect, are the flight tests and theoretical max performance incorrect?

There is a difference between the two (underperforming engines cited versus theoretical) in the 13-20 mph range for boost and surface condition similarities - but in every case that I read, 1900 hp Jumo 213A in 1.85ata and Max Take Off/War Emergency Power, was the cited 'max' conditions for the tests.

Do you have operational evidence that was exceeded in combat for the Dora 9?


Last - the below tests in March 1945 clearly state that the D-9 below was a production aircraft tested with properly adjusted engine..so I would think this series of data should meet objective scrutiny?

--------------------------------------------------------------------------------

E-Stelle
Rechlin Flight Performance Fw 190 D-9
with Jumo 213 A. Erpr. Nr.9003
Teilber.2.


--------------------------------------------------------------------------------

2 March 1945


Summary.
Flight performance of the Fw. 190 D-9 (production version) is given. Speed at altitude was flown with Serial Nr. 006. Various aircraft were checked at 3,000 rpm during continuous testing. Speeds reached 323 to 329 mph (520 to 530 km/h) at sea level and 388 to 395 mph (625 and 635km/h) at 21,325 ft (6.5 km) (about full throttle height, depending on engine adjustment). With 3250 rpm, speeds reached 335 to 342 (540 and 550 km/h) at sea level and 401 to 407 mph (645 and 655 km/h) at 21,653 feet (6.6 km). With 3250 rpm and a take-off weight of 9,480 lbs (4,300 kg), rate of climb was 3,329 ft/min (17.0 m/s) at sea level and 392 ft/min (2.0 m/s) at 33,465 feet (10.2 km).

I. General information.

Airplane model : Fw 190 D-9 W. –Nr.210006
Aerodynamic Wing Area : F = 18,3 m2
Wing span : b = 31,32 ft (10,46 m)
Wing aspect ratio : R = 6,0
Engine : Jumo 213 A (B-4 fuel)
Engine power permissible for 30 min : 3250 rpm
Engine power for continuous operation : 3000 rpm
Air Intake : external scoop without filter
Exhaust system : plain blow back stacks
Pitot tube installation : Bruhn 5 d
Propeller : Heine, 3 blades, compensating core, D = 3,5m, t/D = 11,5%

Aircraft condition:
Standard version with ETC 504 (without wheel cover).

Engine: without gap gasket
Surface: standard, primed and sprayed
Armament: 2 mg 131 in the fuselage with 475 rounds
: 2 mg 151 in the wing with 250 rounds.
Antennas: for Fu G 16
“ Fu G 25
“ equipment
and directional loop cover.
Take-off weight: 9,590 lbs (G = 4350kg) (after n.J.190.213-045 v,31.7.45)
Fuel contents: 141 gallons (640 liter), of which 25 gallons (115 liter) is in the supplementary fuselage tank.
10,229 lbs. (4640 kg), if flown with 300 liter drop tank.

II. Performance tests.

Speeds were ascertained from dynamic pressure tests. Calibrated measuring instruments were used. The interesting Va-area was reached by flight measuring on the test range.
The rates of climb were measured with a carbon recorder.

III. Results of the tests.

The results are on graphs 5 to 9. The level speeds were reached with different engine rpms. It is remarkable that speeds were around 9 mph (15 km/h) higher in the past with Serial Nr. 006 at 3000 rpm (see report of 15.11.44). The current speeds were reached after installation of a new engine, correct engine adjustment, and with the standard propeller. Performance shown in the report of 15.11.44 was determined, through continuous testing, with an unadjusted engine and a D-12 propeller. The speed loss is therefore from engine and propeller differences (D 9 and D 12 propeller).

1.) Level Speeds. They are shown on sheet 5 and apply to a nominal weight of 9,259 lbs. (4200 kg). The V curves are drawn in throughout the entire speed range, so that one can read off the associated Va at each height to each Vw. Sheet 6 shows the dependence of the airspeed on the flying weight and sheet 7 the influence of a 66 gallon (300 l) external tank on the speed.

Example:

Search: Speed at 26,246 feet with a weight of 9,700 lbs, 66 gallon drop tank height, and 2300 rpm.
Given: at 19,685 feet and 9,259 lbs, as per sheet 5, without tank, Vw = 334 mph (538 km/h), Point I: Va = 252 mph (406 km/h ) Weight influence: (as per sheet 6) Va = 252 mph (406 km/h) with 9,259 lbs (4.2 kg) register, point II, draw parallel up to 9700 lbs (4.4 kg), gives new Va (point III). (Δ Va = -6) km/h
Va = 400 km/h
External tank loss (as per sheet 7, Fig.b, point IV: (Δ Va = -20) km/h
380 km/h


The final Va = 380 km/h is registered on sheet 5 (H = 6 km.) Point V and perpendicularly under V on H = 0 km, in the example looked for Vw = 506 km/h read off, point VI.

2.) Climb performance.

It is shown on sheet 8 for 3000 rpm and 3250 rpm

Va climb SL - 22,966 ft Va = 174 mph
26,247 ft Va = 168 mph
29,528 ft Va = 163 mph
32,808 ft Va = 158 mph


3.) Radiator flap test flight.

The influence of the radiator flap position on speed (with empty drop tank) was determined at 6,562 feet with 2700 rpm, (see sheet 7, Fig.e). The entire opening was divided into 10 equal parts, "0 = completely down" and "10 = completely up". The test shows that the speeds are greatest with a 2,3 radiator flap position (approx. flush), i.e. the speed loss is lowest. If possible, level flight should be flown at this position.

[renrich]

Yep, the data in the "Great Book"(not to be confused with the Good Book) says the D9 could do 426 mph at 21650 ft. That is good performance for a WW2 production AC and I think reflects the data in the Mike Williams copy of the flight test. As to 440 mph for a D9, could be! I have seen a test of a "cleaned up" F4U1 with WEP (did you know I was a fan of the Corsair?LOL) that in one run reached 431 mph TAS. Does that mean that the average F4U1 with WEP could do 431 mph? Not in my book. All it means is that a specially prepared F4U1 with WEP hit well over the published performance of that model which is around 417 mph. What it does mean (to me) is that the F4U1 with WEP if it is running reasonably well and is reasonably clean can be an honest 400 mph AC. Same with the F6F5 under the same circumstances. All of this of course at the optimum altitude. I repeat that, to me, the average factory D9, if the engine runs OK is a good honest 400 mph airplane!

[Soren]

Bill,

The 3,329 ft/min climb rate is at Start U. Notleistung, which is 1,750 PS @ 3,250 RPM. At Sondernotleistung with without ETC-504 rack and with wheel covers the climb rate was 4,400 ft/min. At the sam rating but with the ETC-504 and without the wheel covers climb rate was 21 m/s, or 4,100 ft/min. And these are flight test results.

The bottom text you have presented is from a test with a proper working engine, however the test results were all achieved at Steig u. Kampfleistung & Start u. Notleistung, which is 1,590 PS @ 3,000 RPM - 1,750 PS @ 3,250 RPM. Still the test results are far better than those with 0001 & 2 running at the same power.

I'll address the rest later tonight, providing original documents on the subject.

Bottom line though is that the top speed of a good condition production fighter was 612 km/h at SL and 702 km/h at 6.6 km. These are the official figures from when the Dora-9 had already been in service for some time.

[drgondog]

Originally Posted by Soren

Bill,

The 3,329 ft/min climb rate is at Start U. Notleistung, which is 1,750 PS @ 3,250 RPM. At Sondernotleistung with without ETC-504 rack and with wheel covers the climb rate was 4,400 ft/min. At the sam rating but with the ETC-504 and without the wheel covers climb rate was 21 m/s, or 4,100 ft/min. And these are flight test results.

The bottom text you have presented is from a test with a proper working engine, however the test results were all achieved at Steig u. Kampfleistung & Start u. Notleistung, which is 1,590 PS @ 3,000 RPM - 1,750 PS @ 3,250 RPM. Still the test results are far better than those with 0001 & 2 running at the same power.

Soren - where does this March 1945 test imply 1750hp when all of the prior test results were at 1900 and 1.85ata with max take off power expressed to the top performance figures? And to extend the question why would your cited performance figures of 612km/hr at SL/702km/hr at 6.6km exceed the "Theoretical Maximums for wind tunnel drag figures" when the production version was never that clean?

And last, why do none the tests even remotely hint at 3600fpm much less 4,400 fpm? Are you assuming a much more powerful engine than the production Jumo 213A at 1,900 hp, WEP, with B-4 fuel, MW50 boost and 1.85ata?


I'll address the rest later tonight, providing original documents on the subject.

Bottom line though is that the top speed of a good condition production fighter was 612 km/h at SL and 702 km/h at 6.6 km. These are the official figures from when the Dora-9 had already been in service for some time.

Soren - Why is the above series, stipulating new engine, properly tuned, for a production version of the Fw190D-9, and dated only 8 weeks prior to end of war not "official"?

[Soren]

Bill,

I have the original paper on these tests, and they weren't carried out with Erhöhte Ladedrück, if they were it would've been noted. The throttle setting used was Start u. Notleistung which is 1,750 PS. SHould also be clear from looking at the speed figures.

Als if you look at the text, it clearly says "Engine power permissible for 30 min : 3250 rpm" Which is Start u. Notleistung.

And btw, Start u. Notleistung means Take Off & Emergency power

[Soren]

24.3.1945: Dora-9 Climb rate with ETC-504 and without wheel covers; 21 m/s (4,133 ft/min) at Sonder Notleistung


5.7.1944: Dora-9 climb rate without ETC-504 and with wheel covers; 22.5 m/s (4,429 ft/min)


1.10.1944: Official Focke Wulf performance chart 'Leistungs Daten' without ETC and with wheel covers; Dora-9 = 576 km/h at SL running at Start u. Notleistung, 612 km/h running at Sonder Notleistung. 685 km/h at 6.6km running at Start u. Notleistung, 702 km/h at 5.7km running at Sonder Notleistung:


11.3.1945: Dora-9 performance with ETC-504; 612 km/h at SL and 703 km/h at 5.7km with C3 at Sonder Notleistung. 602 km/h at SL and 691 km/h at 5.7 km/h with B4 at Sonder Notleistung. Top speed at Start u. Notleistung with B4: 568 km/h at SL and 680 km/h at 6.6km



So the Dora-9's top speed at Sonder Notleistung without ETC-504 and with wheel covers is 612 km/h at SL and 702 km/h at 5.7 km. With ETC-504 this drops to 602 km/h at SL and 691 km/h at 5.7 km. With ETC-504 and without wheel covers top speed will drop lower yet.

And as to climb rate the Dora-9's climb rate at Sonder Notleistung without ETC-504 and with wheel covers is 22.5 m/s (4,429 ft/min), while with ETC-504 it drops to 21 m/s (4,133 ft/min). At Start u. Notleistung climb rate is 18.7 m/s (3,681 ft/min) without ETC-504 and 17.2 m/s (3,385 ft/min) with ETC-504.

[drgondog]

Originally Posted by Soren

Bill,

I have the original paper on these tests, and they weren't carried out with Erhöhte Notleisting, if they were it would've been noted. The throttle setting used was Start u. Notleistung which is 1,750 PS. SHould also be clear from looking at the speed figures.

Als if you look at the text, it clearly says "Engine power permissible for 30 min : 3250 rpm" Which is Start u. Notleistung.

And btw, Start u. Notleistung means Take Off & Emergency power

That makes sense although there are frequent mentions of 1900 and 1.8 ata with MW50 and B-4 in all of the reports... so what engine performance were you thinking about?

To re-quote

The condition representative of standard production Fw 190 D-9’s during 1945 is as follows: Jumo 213A operating at 1.8 ata with B4 fuel & MW 50, equipped with ETC 504, main wheel fairing doors absent/fixed and engine gap not sealed. Of all the data charted in the compilation curve linked above, that curve best fitting the condition of a standard production Fw 190 D-9 is curve 4 of the Focke-Wulf Fw 190 D-9 chart dated 11.3.45 (the red line). One shortcoming of this curve, when viewed in context with other curves from Focke Wulf’s Flugmechanik Department, is that it assumes the installation of the engine gap seal and is therefore approximately 13 km/h optimistic relative to the condition of delivered production aircraft (with rack minus the drop tank).

Dietmar Hermann summarized FW 190 D-9 performance as follows:

I haven’t read or heard that the D-9 was tested with the Jumo 213 and C3 fuel. I know that at the beginning of development Focke-Wulf made a distinction between the normal Jumo 213 and the Jumo 213 with 100 octane fuel. I think that there was not a problem with the engine; rather there was a problem of the fuel’s availability. In my book I have published one chart from 3.1.45 (page 154) showing FW 190 D-9 performance with B4 fuel with MW 50 injection operating at 2,02 ata (Sondernotleistung ). However, I have no evidence showing that 2,02 ata was enabled by the end of the war. I think that the D-9 was flown either with the 1900 PS update or with MW50 injection (2100 PS).

[drgondog]

Originally Posted by Soren

24.3.1945: Dora-9 Climb rate with ETC-504 and without wheel covers; 21 m/s (4,133 ft/min) at Sonder Notleistung


5.7.1944: Dora-9 climb rate without ETC-504 and with wheel covers; 22.5 m/s (4,429 ft/min)