Dora stall speed

If you are trying to maintain level fligtht at idle, speed will drop rather quick and to maintain altitude you have to increase backpressure on the stick rather fast, hence g-load will be higher than 1.0 and the stall speed will increase!

 

Furthermore most ASIs will read low at low speed and/or high AoA, so the IAS stall speed is usually way lower than a TAS stall speed would be.

 

Don't know if DCS simulates the installation error for the ASI, but in any case, you should only use the ASI value to establish the indicated stall speed (and a low rate of speed reduction and a higher altitude!!!)

G load never exceeded 1.0, because as I said I couldn't maintain altitude, the aircraft started already sinking at 225 km/h TAS, and departed completely at 200 km/h..

Furthermore I cannot match the 165 km/h landing speeds listed in German manuals, be it IAS or TAS, the DCS 190 simply will not fly at those speeds.

The only obvious problem I see is the low CLmax of 1.34 used by ED for the Fw190, despite 1.58 being listed in FW AG documents.

Furthermore I cannot match the 165 km/h landing speeds listed in German manuals, be it IAS or TAS, the DCS 190 simply will not fly at those speeds.

 

The only obvious problem I see is the low CLmax of 1.34 used by ED for the Fw190, despite 1.58 being listed in FW AG documents.

You have a link concerning the quoted landing speed and CLmax?

Very interesting thread! Please do provide the documents, it would be great if it turned out our 190 has a wrong CLmax. Perhaps these refinements would truly make it the formidable fighter it was known as to Allied pilots.

Weight was 4100 kg

 

Tested it on the far eastern valley on the NTTR map, altitude was between 50-100 m.

 

The aircraft toppled over at 200 km/h TAS (Ctrl Y), but it had already started plummiting downward before that.

 

By comparison the 109 & P-51 both stalled at ~160 km/h TAS with 50% fuel ingame.

 

 

Real life figures for clean idle stalls are:

K-4 = ~160 km/h at 3,200 kg

P-51D = ~170 km/h at 4300 kg

190D = ~180 km/h at 4100 kg

It should be taken into account that 50m MSL is not possible on NTTR because of the height of nevada in relation to sea level. It could only be 50-200m AGL. I don’t know how big of a difference this is, but i am pretty sure that i usually don’t stall out at 200kph on caucasus or normandy iirc.

Cheers guys

It could only be 50-200m AGL. I don’t know how big of a difference this is, but i am pretty sure that i usually don’t stall out at 200kph on caucasus or normandy iirc.

No noticable difference at all. Even at 300m the difference would be only approx 2km/h.

The problem is that the OP is using TAS instead of IAS which doesn't make any sense, especially if the DCS Dora takes the IAS/CAS error into account.

No noticable difference at all. Even at 300m the difference would be only approx 2km/h.

 

The problem is that the OP is using TAS instead of IAS which doesn't make any sense, especially if the DCS Dora takes the IAS/CAS error into account.

That indeed would not make sense at all. MSL of Las Vegasitself is 610m. So other parts of the map are situated considerably higher above sea level. This adds will ad up in the long haul considering he used TAS at this height.

Here's the FW AG document listing wing CLmax:

Same CLmax is listed in NACA reports for the same airfoil & similar wing planform:

FW190 landing speed:

It should be taken into account that 50m MSL is not possible on NTTR because of the height of nevada in relation to sea level. It could only be 50-200m AGL. I don’t know how big of a difference this is, but i am pretty sure that i usually don’t stall out at 200kph on caucasus or normandy iirc.

Cheers guys

The tests were done on the far eastern valley on the map which is at 30-40 m MSL.

Here's the FW AG document listing wing CLmax:

Same CLmax is listed in NACA reports for the same airfoil & similar wing planform:

FW190 landing speed:

The Landing Speed sheet refers to the A5 to A6 model - do we know if it was the same for the D9? I mean, they do have different weight, engine and lift characteristics AFAIK.

The tests were done on the far eastern valley on the map which is at 30-40 m MSL.

Thanks for the clarification - i wasn't aware of the altitude drop to the east :thumbup:

Is the CLmax in the first table the theoretical CLmax of the wing or the actual CLmax for the whole airplane?

The second table is completely worthless as a 'similar' planform doesn't mean anything if you don't know e.g. the washout.

The third table doesn't say at which weight the landing speed is valid. Furthermore it's for the A and not the D!

Is the CLmax in the first table the theoretical CLmax of the wing or the actual CLmax for the whole airplane?

 

The second table is completely worthless as a 'similar' planform doesn't mean anything if you don't know e.g. the washout.

 

The third table doesn't say at which weight the landing speed is valid. Furthermore it's for the A and not the D!

Exactly!

Edit: And i just checked the Dora forum - we've been here before:

https://forums.eagle.ru/showthread.php?t=149411

Edit: And i just checked the Dora forum - we've been here before:https://forums.eagle.ru/showthread.php?t=149411

WHAT??? Why on earth did Hummingbird create another thread for exactly the same issue? So much wasted time, sigh. Thanx for the info nevertheless. I'm out.

Yup, same thought

I just tested the FW-190 @ 15C, 50m ASL, 4062 kg (Caucasus map)

After maybe 15 tries, average stall speed is about 170 - 180 km/h IAS by the F2 view, 160-170 km/h by the airspeed gauge.

If you don't keep pulling back on the stick it will indeed sink at about 200 km/h, but if you do you can hold the altitude till the aircraft shudders and drops a wing @ a little over 160 on the gauge.

Hummingbird - perhaps you should check your axis config to make sure you haven't tuned any range off your stick ?

I just tested the FW-190 @ 15C, 50m ASL, 4062 kg (Caucasus map)

 

After maybe 15 tries, average stall speed is about 170 - 180 km/h IAS by the F2 view, 160-170 km/h by the airspeed gauge.

 

If you don't keep pulling back on the stick it will indeed sink at about 200 km/h, but if you do you can hold the altitude till the aircraft shudders and drops a wing @ a little over 160 on the gauge.

 

Hummingbird - perhaps you should check your axis config to make sure you haven't tuned any range off your stick ?

Hmmm, did exactly as you Weta43, pulling back to maintain alt etc, so I don't understand the different results.

Could there be a difference between 2.2.0 Aplha & 1.5.8 beta ? Asking cause your numbers are actually what I'd expect.

Could you attempt the same with the 109 @ 50% & P-51 @ 50% fuel, just for reference ? (don't have 1.5.8 installed because of lack of space)

I will, but tomorrow - it's 23:36 here, and I'm off to bed...

I will, but tomorrow - it's 23:36 here, and I'm off to bed...

Thank you :)

Regardless of PEC matter the CL Max discussion was finished very long time ago because there is no valued argument pro 1.58 except the one figure in the German list of parameters that has unknown exact meaning. On the contrary, 1.35 is confirmed for many WT and flight tests, American, Soviet, etc for the isolated wing, planes using 230 type airfoil s, etc.

So, this attempt to kick the dead horse of 1.58 has no sense now.

This is what I don't understand Yo-Yo, because full scale NACA testing indicate a similar CLmax of between 1.55-1.60.

Hence I don't understand where 1.35 comes from?

It is not a real plane. It is a wooden, shiny polished model, without a stab. Do you no the difference between trimmed and untrimmed lift coefficient, by the way?

Moreover, one test can not be presumed as an ultimate argument - you have to correlate the margin limits values to other sources, because of probable errors, different conditions, etc. I referred to the tests of the isolated wing that gives the similar value BUT FOR THE ISOLATED wing. Keeping in mind that the part of the wing shielded with fuselage does not work as a wing - you will get the same 1.35.

But the P-51 wing windtunnel tests are with a shiny polished model as well.

That said I agree that one test does not give an ultimate argument, but I didn't provide just one either. There are so many reports that point at 1.5 to 1.6 being the actual Clmax of said airfoil selection at the correct Re number that its overwhelming.

Even VSEARO gives a 1.58 CLmax for the isolated wing.

As for trim loss, sure I know, but this goes for all aircraft.

I understand that there are other reports that show a lower Clmax, but the same is true for the other airfoils, incl. the P-51's. However the overwhelming amount show one of 1.5 to 1.6 for the NACA 23015 to 23009 selection at AR of 5.5 to 6 and correct Re number.

Furthermore direct comparisons between two aircraft with close to the same wing loading proved that the NACA 23xxx series does indeed provide more lift than the laminar flow airfoil in actual practice. Here I'm talking about the direct trials between the F4U-1 and P-51B, where the F4U despite a marginally higher wing loading both turned much better and stalled at a lower speed cleaned up than the P-51.

The RAE also tested the P-51B up against a Fw190G and found practically no difference in turn performance between them, again despite the difference in wing loading and undoubtedly higher output of the Merlin/Packard engine in that test.

So here are two practical side by side tests of the real aircraft that also support the majority of the WT tests.

I understand that there are other reports that show a lower Clmax, but the same is true for the other airfoils, incl. the P-51's. However the overwhelming amount show one of 1.5 to 1.6 for the NACA 23015 to 23009 selection at AR of 5.5 to 6 and correct Re number.

 

Furthermore direct comparisons between two aircraft with close to the same wing loading proved that the NACA 23xxx series does indeed provide more lift than the laminar flow airfoil in actual practice. Here I'm talking about the direct trials between the F4U-1 and P-51B, where the F4U despite a marginally higher wing loading both turned much better and stalled at a lower speed cleaned up than the P-51.

 

The RAE also tested the P-51B up against a Fw190G and found practically no difference in turn performance between them, again despite the difference in wing loading and undoubtedly higher output of the Merlin/Packard engine in that test.

 

So here are two practical side by side tests of the real aircraft that also support the majority of the WT tests.

The devs of the new il2 at777 also found a value between 1.3 and 1.4 to be the most accurate.Just like Yoyo.That'a big coincidence.

Can you post a link to those tests you talk ? They seem interesting .