Stalls and turns. Actual testing

[F4UDOA]

Gents,

With the release of the new AH film viewer and the new features included in it IE. a digital speedometer, Hitech and Pyro have given us a giant mallet in which to bludgeon them. Frankly I am surprised at the amount of speculation and the lack of testing by the AH community.  

In any case I am not posting to beat up HT/Pyro but to show people that the myth of uber planes or the truth about uber planes really is. Also to bring to light some small nits to pick.

What I did was use the digital readout of the film viewer to review my 1G and 3G stall test. The test performed were done with 75% fuel except where otherwise indicated. I did not test all A/C, but I did do the ones that seem to get the most attention in AH. I did leave out the Dora and the 109G2. The Dora because it can't turn and everybody knows it and the G2 because I forgot;)
Also some A/C do not iclude flap speed. This is because some A/C flaps will not deploy at speeds where they can reach 3G's

From best to worst

1. A6M5 Zero

1G no flaps= 69MPH  1G Full Flap= 60MPH 3G no Flap= 144MPH 3G 2 notches= 125MPH

2. Spit IX

1G Stall= 86MPH  1G full flap= 76MPH 3G 159MPH 3G full flap 135MPH

3. NIK2

1G 92MPH 1G full flap 80 MPH 3G no Flap =163MPH 3G 2 notches flap = 146MPH

4. Spit XIV

1G 92MPH 1G full Flap= 84MPH 3G no flap= 160MPH  No flap 3G result.

5. F6F-5 Why does this bird have 5 position flaps?? It was supposed to have two position?

1G 96MPH 1G full flap= 84MPH 3G no flap = 165MPH 3G 2 notches flap= 160MPH

6. F4U-1 and F4U-1D The F4U-1 with 50% fuel and the -1D with 75% are comparable loads. The -1 being slightly heavier but with marginal better turning capabilty.

1G stall 102MPH  1G stall full flaps 85MPH 3G stall 175MPH 3G stall 2 notches 165MPH

7. LA-7

1G 99MPH  1G full flap 92MPH 3G no flap= 175MPH left 170MPH right. No flap results possible.

8. P-51D 50% fuel tested for equal duration.

1G 102MPH 1G full flap 91MPH 3G no flap= 181MPH 3G two notches flap 170MPH

P-38L Note; was capable of better turning with more notches of flap.

1G 101MPH 1G full flap= 82MPH 3G no flap= 195MPH 3G 2 notches flap= 175MPH

10. ME-109G10

1G 101MPH 1G full Flap= 87MPH 3G no flap 176MPH no flap 3G possible.

TA-152

1G 105MPH 1G full flap 91MPH 3G no flap 190MPH no 3G flap possible.


There may be some variation as I am not as good with euro A/C but most are within limits.

Any questions or comments?  



 

1G 92MPH  1G full flap= 80 MPH 3G no flap

[Hooligan]

Yes one comment.

For comparison with real world flight test data, would it not have been better to do the tests with 100% internal fuel.

Thanks a lot for doing all the work.

Hooligan

[Wilbus]

Yes, could you please test the Hurricane IIC and Spitfire Mk V aswell as the 190 A5 and A8 please?

Well, if you have time and feel like it some day, very nice test

[F4UDOA]

Hooligan,

I don't usually use different fuel loads for testing except in unusual cases such as the P-51D and F4U-1. Both carry so much internal fuel that only a rank amatuer would take off with 100% with the NME near by. Even in the flight manual it list for stalls a range of weights or a "combat weight". In the test I just did I tried to use a standard combat weight with comparable ranges. More Apples to apples

Wilbus,

I probably will test those birds.

I was just reading a thread on the subject in another forum that irritated me into a quick test. There were no surprises in my results.

Except I have never understood why the F6F has 5 position flaps when it really had two postion electric flaps I believe.

[Tilt]

Originally posted by F4UDOA
Gents,

With the release of the new AH

7. LA-7

1G 99MPH  1G full flap 92MPH 3G no flap= 175MPH left 170MPH right. No flap results possible.

What was the La 7 fuel?

The reccomended landing speed for the La7/La5FN was 137Km/hr ( 85MPH) so it would seem that the stall speeds for the La 7 are too high in AH.............

Unless the plane becomes more stable when wheels are down!

I would have thought that the fully flapped stall speed should be closer to 75 wheels down. I have always wondered if the AH La flight model had accounted for the leading edge slats (slots).

They were a double edged sword...... deploying at approx 210km/hr (131mph)[start at 220 fully at 200] they generated extra lift. However once past the departure speed/ angle the stall was "sudden and quite violent but easily recoverable"


Tilt

[Nashwan]

The reccomended landing speed for the La7/La5FN was 137Km/hr ( 85MPH) so it would seem that the stall speeds for the La 7 are too high in AH.............

Unless the plane becomes more stable when wheels are down!

I think stall speeds were generally lower with undercart down.

One thing you have to be careful of comaring AH stall speeds to R/L stall speeds is the difference between indicated air speed and corrected air speed.

R/L ASI were accurate at only one speed, and usually read high above that speed, low below it.

A pilot's manual would give stall speed in IAS, not CAS. So a given stall speed of 90 mph could well be 100 mph CAS.

[Tilt]

Originally posted by Nashwan

I think stall speeds were generally lower with undercart down.

A pilot's manual would give stall speed in IAS, not CAS. So a given stall speed of 90 mph could well be 100 mph CAS.

Really.......wheels and undercarriage generate lift at these speeds?

I thought F4UDOA's figures were IAS?

I was quoting a landing speed of 85mph......... given this would we not expect the stall speed to be somewhat lower?

Tilt

[NOD2000]

yah u need to test the Hurr I cuz i have out turned many zeke's in that old Hurr

[Nashwan]

I haven't tried the film viewer, but I'd be willing to bet it's showing CAS or TAS, not IAS.

[Mitsu]

You forgot Ki-61!!!

[Andy Bush]

Tilt

It just might.

Power setting may play a role in stall speeds...with the gear down, the resulting higher power setting may result in a reduction of stall speed.

[F4UDOA]

Actually the 1G stall speed of some of the birds tested is a little high. The F4U and F6F are high while the P-38 seems a little low. In fact many I have tested so far are right around 100MPH. Not really that accurate considering how precise HTC normally is.

However where HTC really shines is the 3G stall accuracy. It seems to be historically correct on most a/c.

Will be testing the other birds shortly BTW.

[Apar]

Could you pls describe how you performed the tests (1G and 3G stalls)

Thx

Apar