Spitfire Mk.XIV vs P-51D Mustang

[Soren]

Originally Posted by KrazyKraut

But are they cross-checked with German losses?

I'm sure by the time the Dora arrived in any relevant numbers it simply was too late to get the recognition it might have gained if available in late '43 or early '44. It's funny though how it is seen as the ultimate German piston fighter in modern public opinion. In the end it only equalized the advantage the Allies had gained with the P-51. Back in its best days the Anton did far better than the Dora. Because it gave a performance advantage and didn't just equalize one.

The Dora didn't just equalize things, it also gave the Germans the advantage at low to medium altitudes. (Hence its sterling record in the east where it litterally slaughtered the VVS fighters) The Dora-9 was faster than the Allied fighters at low to medium alts, climbed faster and featured unrivalled manuverability at the speed regimes where most fights took place. Sadly for the Germans however there were never enough proper trained pilots, fuel or Dora's to allow it to have any significant impact. Furthermore the fights on the western front usually took place at alts greater than 25,000 ft. But the Dora did nonetheless cause the escorts some problems, as Willi Reschke relates in his book 'Wilde Sau', as it gave an enormous boost in high alt performance compared to the Anton.

[KrazyKraut]

Well I disagree. The Dora was a nice fighter and somewhat superior at low-to-medium altitudes to contemporary western props (though the P-51 was still faster down low iirc), but the difference (real and felt) was never as big as the difference the Anton made in late '41 / early '42. Considering the combat altitudes the Dora was still at a disadvantage a lot of times.

The VVS got slaughtered by Antons and Bf 109s aswell, the reasons mostly lie elsewhere. On the eastern front, in theory, the difference between Anton and Dora should be relatively small as the combat altitudes were so low.

[Soren]

KrazyKraut,

The Dora-9 was faster than any Allied fighter at low alt, including the P-51, and much faster than the Anton. The Dora-9 was a big improvement on the Anton.

[kool kitty89]

Price comparisons aren't always best either, as -durring wartime- time (man hours) required to complete them is a much more important factor than actual cost. (actual use of strategic materials would be important too, less so for the US though given the massive resourses)

If somthing is more expensive but can be built in less time the latter could be advantageous. (again, use of materials is an independent concern as well)

I'm not sure on the exact figures but iirc (from several comparisons made previously on this forum) the P-38J cost about 2x the P-51, while the P-47 cost ~1.5x the P-51 (this remaining fairly constant from 1944 onwards), however the construction times fluctuate cosiderably more (generally decreasing as the war progressed) but in one comparison the P-47 took ~2x as long as the P-51 and the P-38 ~1.5 times as long I think.


In peace time cost (and maintainence costs) would be much more of a concern.

[davparlr]

Originally Posted by Soren

The average P-51B wasn't much faster above 20kft Davparlr, and maneuverability still wasn't as good as that of the Dora. The fw-190Dora-9 held clear advantages in speed, climb rate & maneuverability up to 25 kft,

?

All performance figures are for fighter weight, 9069 lbs for the P-51B, and 9480 lbs for the Fw-190D-9.

Around 15k ft, performance comparison, at fighter weight, between the P-51B and the Fw-190D-9 is roughly equivalent.


Airspeed
P-51B 428 mph
Fw-190D-9 432 mph
Very slight advantage Fw

Climb
P-51B 3700 ft/min
Fw-190D-9 3740 ft/min
Very slight advantage Fw

Turning – advantage Fw

Dive - advantage P-51

However at about 16k ft, the Fw-190D-9 engine starts losing significant power, while the P-51 engine is into its second wind. This starts to show up around 20k where the P-51 gains significant improvement of airspeed over the Fw.

Airspeed
P-51B 442 mph
Fw-190D-9 426 mph
Significant advantage P-51

Climb
P-51B 2940 ft/min
Fw-190D-9 2992 ft/min
No advantage here for the Fw since climbing would only improve P-51 performance over the Fw.

Turning – advantage Fw

Dive – advantage P-51

Above that, the P-51B is continually improving in performance, with only turn performance an advantage for the Fw-190D-9, a historically not an overpowering advantage. At, 25k,

Airspeed
P-51B 440 mph
Fw-190D-9 417 mph
Significant advantage P-51

Climb
P-51B 2650 ft/min
Fw-190D-9 2158 ft/min
Advantage P-51

Turning – power loss will affect turn performance but I’ll give advantage to Fw

Dive – Advantage P-51

So, at bomber altitudes, 20k and above, the Fw-190D-9 was at a disadvantage and was not the best aircraft for the job. The Bf-109K was a much better choice.

The Fw-190D-9 a/s numbers are taken from Fw chart showing Fw-190As, Ds, and Ta-152s. Other charts show various a/s for different D-9s (different engines?). These show some versions better at lower altitudes but worse at higher altitudes. All show the Fw-190D-9 falling behind the P-51B in a/s above 15k, significantly above 25k.

However caliming it was no contest is wrong,

Less wrong than your statement “as the "Dora" was superior in every aspect of flight except diving !”, as I have just shown.

Sadly for the Germans there were never enough Dora-9's to go around and they were always grossly outnumbered by the Allied escorts.

Their best use would have been for protecting the Me-262s, more of which were really needed by the Luftwaffe.

The real champ at all alts was the Dora-13 which was superior to any Allied fighter in service from SL and up.

The Dora-13 looked like an impressive aircraft, out performing the Ta-152H up to 37k. It makes one wonder why they spent resources on the Ta-152H when there was no threats up there. I’ve commented on this before. It still would have been outperformed by the P-51H up to 25k, which, by the way, was in service, as was the Tempest II, which would have outperformed the Dora-13 to 20k.

The Dora-9 was faster than the Allied fighters at low to medium alts, climbed faster

This is not correct. The Tempest II, which was delivered, was MUCH faster at all altitudes compared to the Fw-190D-9. The P-51B airspeed and climb performance was within error calculations of both speed and climb up to 15k where it started to exhibit superior performance.

SL
Airspeed
Fw-190D-9 385 mph
P-51B 386 mph
Tempest II 416 mph


Climb
Fw-190D-9 4429 ft/min
P-51B 4700 ft/min
Tempest II 4700 ft/min

5k
Airspeed
Fw-190D-9 405 mph
P-51B 400 mph
Tempest II 425 mph

Climb
Fw-190D-9 4134 ft/min
P-51B 4500 ft/min
Tempest II 4200 ft/min

10k
Airspeed
Fw-190D-9 413 mph
P-51B 420 mph
Tempest II 440 mph

Climb
Fw-190D-9 4134 ft/min
P-51B 3750 ft/min
Tempest II 3900 ft/min

It is obvious that the Fw-190D-9 did not have a significant advantage over allied aircraft at any altitude.

Sadly for the Germans however there were never enough proper trained pilots, fuel or Dora's to allow it to have any significant impact.

Had the Germans fielded a threatening number of Fw-190D-9s or Bf-109ks in late 44, you would have seen a rapid build up of P-51Hs, P-47Ms, Tempest IIs, and possibly P-72s, by January, ‘45, which would have negated any prop planes the Luftwaffe could field (except at very high altitude where the Ta-152H would still reign supreme.)

The truth is that by fall, 1944, the Allies considered that the war in Europe could be won with the aircraft on hand and did not pursue advanced aircraft, except for performance evaluation like the P-80, in the theater. Had the threat changed, this would have changed.

[KrazyKraut]

The truth is that by fall, 1944, the Allies considered that the war in Europe could be won with the aircraft on hand and did not pursue advanced aircraft, except for performance evaluation like the P-80, in the theater. Had the threat changed, this would have changed.

We had this a couple of times now and there is no "truth" in neither what you or Soren say, because it's all just seculation. Besides that, the Tempest II never seeing any action was due to a pretty messed up production planning not because it wasn't needed. It also makes more sense to evaluate the Dora vs. the P-51 D because the transition had progressed well when the Dora arrived in numbers and I highly doubt the USAAF would've ever switched back because of the B's small performance advantage.

I think the "had this happened had that happened" game has been played to death. Let's focus on the things that actually fought.

[drgondog]

Originally Posted by KrazyKraut

We had this a couple of times now and there is no "truth" in neither what you or Soren say, because it's all just seculation. Besides that, the Tempest II never seeing any action was due to a pretty messed up production planning not because it wasn't needed. It also makes more sense to evaluate the Dora vs. the P-51 D because the transition had progressed well when the Dora arrived in numbers and I highly doubt the USAAF would've ever switched back because of the B's small performance advantage.

I think the "had this happened had that happened" game has been played to death. Let's focus on the things that actually fought.

At least 20% of 8th AF FC in April 1945 were still B/C with the 1650-7 Merlin.

[KrazyKraut]

I know but just because the B and C had some better performance figures doesn't make them the overall better planes and I think the D would be a better comparison to the Dora.

For a similar case: Some of the early 109 Gs also had better performance than the G-6 and were used for a long time after the latter had been introduced, still it makes more sense to take the G-6 if you want to compare '43 fighter aircraft.

[drgondog]

Originally Posted by KrazyKraut

I know but just because the B and C had some better performance figures doesn't make them the overall better planes and I think the D would be a better comparison to the Dora.

For a similar case: Some of the early 109 Gs also had better performance than the G-6 and were used for a long time after the latter had been introduced, still it makes more sense to take the G-6 if you want to compare '43 fighter aircraft.

Well the 51D had more guns and ammo but weighed 600-900 piunds more for same airframe. 51B turned better and climbed better and was faster. One of those will usually work to your advantage. After all the wheel uplock and tail mods they were structurally more sound in a high pullout - load to load being equal.

Malcolm Hood had good visibility but not as good as teardrop so that is a downcheck, ditto the 4 vs 6 50 cal and ammo.

[Juha]

Hello KrazyKraut
Later Tempest Vs with Sabre IIB were faster than 190D-9 at sea level and up to appr 9500ft and then again from 19500ft upwards, early Tempest Vs with Sabre IIA were faster than 190 D-9 between appr. 1,000 - 10,000 ft and then again from 19500ft upwards.

Juha

[kool kitty89]

OK, heres the thread I was referring to, but it doesn't include the P-51 like I'd thought:
http://www.ww2aircraft.net/forum/tec...aft-10190.html (Man hours to build aircraft)

[kool kitty89]

Originally Posted by davparlr

However at about 16k ft, the Fw-190D-9 engine starts losing significant power, while the P-51 engine is into its second wind. This starts to show up around 20k where the P-51 gains significant improvement of airspeed over the Fw.

Airspeed
P-51B 442 mph
Fw-190D-9 426 mph
Significant advantage P-51

Inless you're talking about the P-51 at 75" boost (with 100/150 grade fuel) that's much too fast.

P-51 Mustang Performance (which tends to be a bit biased toward allied a/c anyway)

Gives ~420-426 mph at 20,000 ft at 67" for the P-51B with either the 1650-3 or -7. (as power oupput was similar for both engines at this altitude)

I don't think the Mustang had a significant speed advantage over the Dora until ~23,000 ft.




And Bill,
Don't forget the P-51D's armament was also less prone to jamming than the earlier mustangs. (and wasn't there a structural redesign that allowed higher diving speeds without risking a structural failure)

[Soren]

The P-51B didn't climb at 4,700 ft/min Davparlr, not even at 75" MAP where at at the most reached 4,380 ft/min.

At 75" MAP the P-51B-15's performance figures were as follows:

Top Speed: 388 mph at SL, 444 mph at alt.
Climb rate: 4,380 ft/min

These figures are from WWIIaircraftperformance.

[davparlr]

[quote=KrazyKraut;404006]

Originally Posted by KrazyKraut

We had this a couple of times now and there is no "truth" in neither what you or Soren say, because it's all just seculation.

Well, I admit that “the truth” was in my opinion only. However, I still think my premise is correct.

Besides that, the Tempest II never seeing any action was due to a pretty messed up production planning not because it wasn't needed.

I’ll bet that if there was a critical need, the production problem would be solved quickly.

It also makes more sense to evaluate the Dora vs. the P-51 D because the transition had progressed well when the Dora arrived in numbers and I highly doubt the USAAF would've ever switched back because of the B's small performance advantage.

The fact that there were a number of P-51Bs flying at wars end has been established.

But here are some comparisons with the P-51D. There is a strange note here. The climb rates have been modified to 75” Hg, however, I have not determined a factor for updating airspeed to 75” Hg yet, so the airspeed numbers below for the P-51D is at 67” Hg. I expect the 75” Hg numbers to be closer to the P-51B numbers but a bit less. P-51B airspeed at 75” Hg numbers are in parenthesis.

20k
A/S
Fw-190D-9 426 mph
P-51D 421 mph (442 mph)

Climb
Fw-190D-9 2992 ft/min
P-51D 3080 ft/min
Note: I made an error in the previous entry in the P-51B climb at 20k, rate should be 3480 ft/min, not 2940 ft/min.

25k
A/S
Fw-190D-9 417 mph
P-51D 440 mph (440 mph)

Climb
Fw-190D-9 2158 ft/min
P-51D 2350 ft/min

And, with a better dive, I think you can see that even the P-51D would be quite a handful for the Fw-190D-9 at 20k ft. and above.

Originally Posted by Kool kitty89

Inless you're talking about the P-51 at 75" boost (with 100/150 grade fuel) that's much too fast.

By the time the Fw-190D-9 arrived, 75” boost had been approved,

http://www.wwiiaircraftperformance.o...e-v-1650-7.jpg

and used.

http://www.spitfireperformance.com/m...ger-6nov44.jpg

Of course I used 75" boost.

P-51 Mustang Performance (which tends to be a bit biased toward allied a/c anyway)

Are up implying that Spitfire Performance alters government test documents to reflect a bias?

I don't think the Mustang had a significant speed advantage over the Dora until ~23,000 ft.

I think you will find that test results at 75” boost does not support this comment (see my data.)

Originally Posted by Soren

The P-51B didn't climb at 4,700 ft/min Davparlr, not even at 75" MAP where at at the most reached 4,380 ft/min.

The test report you refer to has a test weight of 9680 lbs for the P-51B which is about the fighter weight of the P-51D (according to “America’s Hundred Thousand”). The fighter weight of the P-51B is about 9070 lbs. I think if you calculate climb performance with 600 lbs less, you will be pretty close to the 4700 ft/min rate at SL.

[kool kitty89]

Didn't the P-51 have a problem with the 100/150 grade fuel due to the merlin's tendency for spark plugs to foul rather heavily and rapidly when using it. (compared to the R-2800 and V-1710 which were deemed satifactory in terms of fouling using 100/150 grade)