TAS speeds (horizontal flight) for all DCS WWII fighters at three levels

[tapi]

Just made a test of maximum TAS speeds (horizontal flight) for all late war WWII fighters at sea level, at 3300 m (10000 ft) and at 6100m (20000 ft).

 

Parameters of the test:

DCS Open Beta 2.5.6.57530

Normandy map, temperature 20°C, pressure standard atm 29.92 inHg, wind 0 kt

fuel 50%

planes trimmed for horizontal flight

measured flight duration at least 1 min or more until speed stops rising

TAS read from the status bar

 

Power settings:

P-47D-30: water injection and turbocharger , 71″ @ 2700 RPM

P-51D: WEP, 67″ @ 3000 RPM

Spitfire Mk.IX: +18 @ 3000 RPM

FW 190D: MW50, 3250 RPM

FW 190A-8: notleistung 2700 RPM (1.4 ATA)

Bf 190K-4: MW50, 1.75 ATA (2800 RPM)

 

Measured speeds:

 

P-47D-30

615 km/h

646 km/h

670 km/h

 

P-51D

592 km/h

631 km/h

674 km/h

 

Spitfire Mk. IX

525 km/h

585 km/h

611 km/h

 

FW 190D

594 km/h

646 km/h

698 km/h

 

FW 190A-8

542 km/h

572 km/h (with 2nd stage of supercharger ON)

628 km/h

 

Bf 109K-4

592 km/h

637 km/h

678 km/h

 

Conclusion:

At sea level the winner is P-47D

At 3300m P-47D, FW 190D and Bf 190K are very close to each other

At 6100m the winner is FW 190D

 

P.S. Misson files attached if anyone wants to verify measured numbers

_speed_tests.rar

[petsild]

A very handy :thumbup: comparison of the performance, thanks.

 

[bart]

Nice work, thanks for doing this.

 

I've often wondered what the true comparison would be between all the warbirds. Now I know...

[Zunzun]

First of all, thank you for taking the time to do the test.

One thing I noticed is you didn´t use standar atmosphere condition. Although your pressure is right, the temp should be 15º (I have not calculate any desviation may have happened though).

Also,P-47D speed seems too much at sea level (615kph). At 72 inches, the P-47M in the test report I have seen did 365-368mph (around 585-595kph).

Also, does anyone know why at sea level the boost goes to 71"? The engine was rated for 64". This happened also in Il2 (higher boost at sea level). Is it right or a bug? If right, what is the explanation?.

[grafspee]

Also, does anyone know why at sea level the boost goes to 71"? The engine was rated for 64". This happened also in Il2 (higher boost at sea level). Is it right or a bug? If right, what is the explanation?.

Like it was said already P-47 does not have automatic boost control like in other planes like P-51,Spitfire.

So it is possible to overboost.

If you take P-47 in to climb and you set your boost for example 50" or 52" you will notice that boost will go up during climb so pilot have to retard boost lever to keep boost with limits.

 

[grafspee]

Would you consider adding top speed test at 35000ft i think at this alt P-47 should rule :)

[tapi]

First of all, thank you for taking the time to do the test.

One thing I noticed is you didn´t use standar atmosphere condition. Although your pressure is right, the temp should be 15º (I have not calculate any desviation may have happened though).

Also,P-47D speed seems too much at sea level (615kph). At 72 inches, the P-47M in the test report I have seen did 365-368mph (around 585-595kph).

Also, does anyone know why at sea level the boost goes to 71"? The engine was rated for 64". This happened also in Il2 (higher boost at sea level). Is it right or a bug? If right, what is the explanation?.

 

I agree, you are right 15° would be better and more precise. Hopefully, it is not a big problem, at least ALL a/c used the same though not ideal temp (20°) so the differences among a/c should be roughly the same.

Yes, P-47D is probably way too fast at sea level in DCS. IRL pilots usually would not overboost the engine but in DCS they do always if it is allowed. So I used max possible MP in my test.

[tapi]

Would you consider adding top speed test at 35000ft i think at this alt P-47 should rule :)

 

My test was only a brief one. I do not intend to invest much time into it. If someone wants to add high altitude data it would be great. I have attached my .miz files at the first post if someone wants to use them for some additional tests...

[Zunzun]

Like it was said already P-47 does not have automatic boost control like in other planes like P-51,Spitfire.

So it is possible to overboost.

If you take P-47 in to climb and you set your boost for example 50" or 52" you will notice that boost will go up during climb so pilot have to retard boost lever to keep boost with limits.

 

Yes, I knew about the boost regulator and its behaviour in the climb. But I was referring to sea level so that behaviour in the climb shouldn't apply. Should it?

It's that the regulator doesn't limit the engine to 64" and the coupling of the mechanical supercharger and the turbocharger overboost it beyond the plackard limit?

If that was correct then the effect should be present up to 7000ft (the limit of the mechanical supercharger).

 

 

 

[grafspee]

 

Yes, I knew about the boost regulator and its behaviour in the climb. But I was referring to sea level so that behaviour in the climb shouldn't apply. Should it?

It's that the regulator doesn't limit the engine to 64" and the coupling of the mechanical supercharger and the turbocharger overboost it beyond the plackard limit?

If that was correct then the effect should be present up to 7000ft (the limit of the mechanical supercharger).

 

 

 

Mechanical supercharger is geared so throttle and engine rpm are regulating boost, but this is only managed by pilot so manual mode 100%.

Boost regulator basically keeps constant exhaust pressure on turbine inlet side.

So turbo work load is constant more or less. For example turbo increase inlet pressure by 10 inHg.

Now look at ram air inlet, when plane is stationary no ram effect present so the boost regulator will indirectly limit MAP to 64 +- 1-2inHg but when plane is flying fast ram air will add additional boost, and boost regulator is no way in position to compensate. P-47 don't have automatic boost regulator like Spitfire or P-51.

If you would configure boost regulator to limit 64" at 400mph plane will not be able to boost up to 64" at lower speed.

I have heard that P-47 later models were equipped with boost regulator which was controlling MAP and was able to prevent over boosting. But i don't know much about it

[Zunzun]

 

Mechanical supercharger is geared so throttle and engine rpm are regulating boost, but this is only managed by pilot so manual mode 100%.

Boost regulator basically keeps constant exhaust pressure on turbine inlet side.

So turbo work load is constant more or less. For example turbo increase inlet pressure by 10 inHg.

Now look at ram air inlet, when plane is stationary no ram effect present so the boost regulator will indirectly limit MAP to 64 +- 1-2inHg but when plane is flying fast ram air will add additional boost, and boost regulator is no way in position to compensate. P-47 don't have automatic boost regulator like Spitfire or P-51.

If you would configure boost regulator to limit 64" at 400mph plane will not be able to boost up to 64" at lower speed.

I have heard that P-47 later models were equipped with boost regulator which was controlling MAP and was able to prevent over boosting. But i don't know much about it

 

That makes sense. Thanks :thumbup:

[Blackbird12]

I think the P-47 is way too fast, from the little I investigated, I can't tell for the spitfire and the 109 but I searched a lot for 190 A8, and the A8 is still missing ~ 10 km/h and (sea level at least).I don't want to say that allied fighter are biased (for the p47), but those numbers seems to be the worst we can find on performance charts for the A8

[tapi]

Well, if DCS A-8 has Erhöhte Notleistung it would add 15-20 km/h. As far as I know EN was on majority of A-8 except the first batches (and these were supposed to be upgraded later as well).

 

DCS P-47 Is probably faster then IRL at least at the sea level.

[Blackbird12]

Well, if DCS A-8 has Erhöhte Notleistung it would add 15-20 km/h. As far as I know EN was on majority of A-8 except the first batches (and these were supposed to be upgraded later as well).

 

DCS P-47 Is probably faster then IRL at least at the sea level.

 

From my research, A8 should fly at about 550-555 km/h (SL) without EN and 570-580 km/h (SL)with it and if we could remove the outboard mg, we can add 6-7 km/h, so it could be very competitve (in fighter role) with or without the EN

[tapi]

Not a primary source but very reliable secondary one: Smith & Creek, FW 190 (3 volumes) - p. 410 FW 190A-8 speeds:

[Blackbird12]

Not a primary source but very reliable secondary one: Smith & Creek, FW 190 (3 volumes) - p. 410 FW 190A-8 speeds:

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I can't be confident with secondary sources since almost all of them speak about MW50 on the A8 wich never had it ( I don't say it is the case of this one)

 

I have some sources form wich I conclude the 550 without EN :

 

I post them in the chronogical order

 

January 1944

 

 

March 1944 ( I attach the pdf to the post)

 

 

May 1944 (the document is from november 1944 but you can see may 1944 on the bottom of it

 

 

The other sources from october 1944 and january 1945 tell for 545 km/h

 

 

 

I have this one too but don't know the date

 

 

​

The speed seems to drop gradually, since the war end approach so maybe the production quality or small changes on the aircraft ? I can't tell

 

Sorry for the long post but looked a lot for A8 and want to share, I have looked for the other version too, wich are a little bit faster due to better aerodynamics (less and smaller weapons)

Fw_190_A-8_15-3-44.pdf

[tapi]

Interesting data, thanks very much for sharing.

 

If I read the graphs correctly, these are the speeds for A-8 at sea level:

(pls correct me if I read wrong some data)

 

January 1944

2700 @ 1,5 ATA 555 km/h

2700 @ 1,65 ATA 578 km/h

 

March 1944

2700 @ ? ATA 530 km/h

2700 @ 1,5 ATA 555 km/h

2700 @ 1,65 ATA 580 km/h

 

May 1944

graph of bad quality, but seems the same like the one from March 1944

 

October 1944

2700 @ 1,50 ATA 545 km/h

2700 @ 1,65 ATA 565 km/h

 

January 1945

2700 @ 1,52 ATA 545 km/h

2700 @ 1,65 ATA 565 km/h

 

Unknown one

2700 @ ? ATA 556 km/h

 

Seems to me that graphs shows cca 545-555 km/h for 1,5 ATA.

That IMO could be consistent roughly with 541 km/h for 1,42 ATA

 

P.S. I think we should count at least with some little error margins due to methods of measurements even in official data.

[Blackbird12]

Interesting data, thanks very much for sharing.

 

If I read the graphs correctly, these are the speeds for A-8 at sea level:

(pls correct me if I read wrong some data)

 

January 1944

2700 @ 1,5 ATA 555 km/h

2700 @ 1,65 ATA 578 km/h

 

March 1944

2400 @ ? ATA 530 km/h

2700 @ 1,5 ATA 555 km/h

2700 @ 1,65 ATA 580 km/h

 

May 1944

graph of bad quality, but seems the same like the one from March 1944

 

October 1944

2700 @ 1,50 ATA 545 km/h

2700 @ 1,65 ATA 565 km/h

 

January 1945

2700 @ 1,52 ATA 545 km/h

2700 @ 1,65 ATA 565 km/h

 

Unknown one

2700 @ ? ATA 556 km/h

 

Seems to me that graphs shows cca 545-555 km/h for 1,5 ATA.

That IMO could be consistent roughly with 541 km/h for 1,42 ATA

 

P.S. I think we should count at least with some little error margins due to methods of measurements even in official data.

 

You confused the 1.58 and 1.65 at sea level, the 1.42 et 1.58 are the only possible at sea level, 1,65 is for second superchagarger

 

so ~ Level 0 to 1500 meter = 1.58 for the maximum speed and ~ 2300 meter to 5500 is 1.65 for the maximum speed too, the gap is for the speed difference between 1.42 and 1.58 or 1.65.

 

January 1944

2700 @ 1,42 ATA 555 km/h

2700 @ 1,58 ATA 578 km/h

 

March 1944

2400 @ 1,32 ATA 530 km/h

2700 @ 1,42 ATA 555 km/h

2700 @ 1,58 ATA 580 km/h

 

May 1944

graph of bad quality, but seems the same like the one from March 1944

 

October 1944

2700 @ 1,42 ATA 545 km/h

2700 @ 1,58 ATA 565 km/h

 

January 1945

2700 @ 1,42 ATA 545 km/h

2700 @ 1,58 ATA 565 km/h

 

Unknown one

2700 @ ? ATA 556 km/h For this one very hard to tell if it's a 1,42 or the 1,58 but when there is 1,58 they specify it

 

There is also the calculated estimation wich tell 558 km/h @ SL @ 1,42 ATA. In a test flight for a Fw 190 D9, they managed to be 5 km/h slower that calculeted estimations (with polished surface) but I read a lot of test flight for 190 and speed are always differents, never the same in same configuration.

I think those charts are for aircraft in their best configuration for the moment, and with closed radiator flaps and maybe polished surface.

 

 

 

 

 

[tapi]

OK, understand. Thanks for your correction. Then it seems you are right :thumbup:

Looks like ED prefered lower values from the late 1944 and 1945 charts. i.e. cca 545 km/h.

So it seems that in case of DCS A-8 (542 km/h) there is a difference cca 10-15 km/h (not a big one but worth to consider) from the earlier charts and cca 2-5 km/h from the late charts (a very small difference that could be caused by measurement errors on either side)

[iFoxRomeo]

@Blackbird12 All these diagrams are calculated values. They are higher than what the real aircraft could achieve. You are correct with MW50. It was tested; no significant gain was the result and little cracks in the engine appeared during the testphase. I have to look for the source for this, will post it when I find it. Instead increased boost pressure was used and provided a significant power increase.

1.65ATA was used for the "JABOREI" case with additional C3 injection and only for the "bodenlader" (1st stage of the booster).

In the fighter configuration 1.58ATA 1st stage, 1.65ATA 2nd stage.

 

Fox

[Blackbird12]

@Blackbird12 All these diagrams are calculated values. They are higher than what the real aircraft could achieve. You are correct with MW50. It was tested; no significant gain was the result and little cracks in the engine appeared during the testphase. I have to look for the source for this, will post it when I find it. Instead increased boost pressure was used and provided a significant power increase.

1.65ATA was used for the "JABOREI" case with additional C3 injection and only for the "bodenlader" (1st stage of the booster).

In the fighter configuration 1.58ATA 1st stage, 1.65ATA 2nd stage.

 

Fox

 

So how do we know these are calculated values ? Because for me "Flugleistung" is "Flight performance" and that says what it says, and for the test flight (notably the 4 we have on http://www.wwiiaircraftperformance.org/fw190/fw190a8.html) we don't even know how they could transform (accurately) the values from IAS to TAS (wind, temperature, airspeed indicator accuracy), the state of the radiators flaps (cause I think they can't go with ATA 1.42 2700rmp with them closed for too long) so wich is the more imprecise ? I think we should take all of these charts and make something like an average.

 

I would like to add that in a test on the A8 they changed the supercharger caused it failed and the plane gained 10 km/h, a "little" change that changed the speed, the aircraft was the same.

 

[iFoxRomeo]

For example: www.wwiiaircraftperformance.org/fw190/Fw_190_A8_733705_Rep2.pdf

 

A Flugbericht contains information like when, who, what, how etc,; it has a little bit more than only one graph. At least there should be some measurement points on the graph that are then connected to a line.

At first I also thought that these graphs are taken from testflights, but these are calculations.

 

It doesn't matter if WE know how they transformed values. They knew better than WE(majority here in the forums) do now.

 

Yes they changed the engine. I wouldn't consider this as "little". Obviously that previous engine was faulty.

 

I made some comparisons to the linked testflight with the DCS:FW-190A8. And it did compare quite well with Startleistung. Kampfleistung was a little bit too low.

 

Fox

[Blackbird12]

For example: www.wwiiaircraftperformance.org/fw190/Fw_190_A8_733705_Rep2.pdf

 

A Flugbericht contains information like when, who, what, how etc,; it has a little bit more than only one graph. At least there should be some measurement points on the graph that are then connected to a line.

At first I also thought that these graphs are taken from testflights, but these are calculations.

 

It doesn't matter if WE know how they transformed values. They knew better than WE(majority here in the forums) do now.

 

Yes they changed the engine. I wouldn't consider this as "little". Obviously that previous engine was faulty.

 

I made some comparisons to the linked testflight with the DCS:FW-190A8. And it did compare quite well with Startleistung. Kampfleistung was a little bit too low.

 

Fox

 

I don't think it's very fair to use only one source, and as I say above on a test with a D9 they managed to be 5 km/h slower than calculations, so many things can change the speed in real test flight, I think we can assume that calculations are better but a good indication, because calculations can be very precise if we take a littlle margine of course, (there is nothing more precise than mathematics I think) All sources calculations, test flight should be observed.

 

For the d9 http://www.wwiiaircraftperformance.org/fw190/Fw_190_D-9_210001_FB_Nr3.pdf For traduction look for Flight Report FW 190 D-9/210001 Nr. 3 on http://www.wwiiaircraftperformance.org/fw190/fw190d9test.html

 

I will take one more look on the others versions like A4 A5, the main différence is mg131 instead of mg17 and and mg151 in the wing instead of mg FF

 

[grafspee]

 

(there is nothing more precise than mathematics I think) All sources calculations, test flight should be observed.

 

 

It is not about math, it is about values which were taken for calculations, if those numbers are wrong, calculations will be wrong as well.

There is nothing better then live speed tests.

Calculations often may miss some variables which impact real plane top speed.

 

[iFoxRomeo]

You can use what you want. But I prefer real testflights as they show the real aircraft and not a calculated one. A single report contains several flights by several pilots. That's how its is still done today.

Calculations are a good "estimate" what to expect from the projected aircraft. The errors can go in both directions. Flight tests remain the real thing, for several reasons: Engines perhaps don't deliver the promised power, airframes create more drag than thought due to big tolerances during the building process etc..