Why does the Spit VIII roll slower than the IX or XIV?

[Bruno]

Originally posted by Karnak
Given how much the clipped wings increased the roll rate of the Spitfire I am not prepared to assume that the extended wings only very slightly reduced the roll rate.

So give every bit of the increase in the VIIIs roll rate above 1 sec to the extended wing tips in that test. Thus the 1 sec you are left with matches up with AH, doesn't it?

Which was kinda my point...

[Bruno]

19. Rate of roll is very much the same.

That is not a scientific conclusion, its an opinion.

Very much the same = exactly the same?

Slighly worse?

Slightly better?

etc...

[Karnak]

Originally posted by Bruno
So give every bit of the increase in the VIIIs roll rate above 1 sec to the extended wing tips in that test. Thus the 1 sec you are left with matches up with AH, doesn't it?

Which was kinda my point...

So you're suggesting that shortening the ailerons by about 8 inches would add a full second to the roll time and then extending the wing tips only .5 seconds?  That is hard to believe.  And it doesn't match the effect of clipping the wings..

Neither the text you posted or mine is scientific.  Yours was more detailed, but for the wrong wings.  Very much the same sounds like it would be very close, not 10 degrees per second slower.  That would be  "19. Rate of roll is similar." at best.  10 degrees per second is not slight.

[Bruno]

No what I am suggesting is that the shortened ailerons did have an effect on the roll rate, whether it be 1 sec or .5 it doesn't matter. Let's say its .5 sec, so what? The roll rate of the VIII and the IX weren't the 'same'.

The conclusion:

The smaller span ailerons combined with extended wing tip give the Spitfire VIII an inferior rate of roll.

That inferior roll rate reached '1.5 seconds superiority for the Mark IX over the Mark VIII.'

The shortened ailerons impacted roll rate. If you claim that 10 degree per sec is too much, then prove it. If you are going to argue over +/- .5 sec  of roll then I chalk that right up there with those old threads about how the the 'A8 is 4 mph to slow otd' and Ram's 'the A-5 is 12 mph to slow'.

EDIT:
Also, it should be noted that the A-5 max roll rate of just 131 degrees (left) is considerably slower then it should be. Far in access of the 10 degrees we talking about here with the VIII.

[Karnak]

And I am saying that you can base very little to nothing on that one off hand comment based on a wing that we aren't even discussing.


What should the Fw190A-5's roll rate be at 300mph?  Keep in mind that Widewing's test was not of sustained roll rate.  Widewing's test was not at all of the max roll rate.  Isn't there supposed to be a 190 FM revision coming in any case?

The Spits are supposed to be done now, so if this is an issue and if it is to be addressed it needs to be addressed now.  I am still open to it being correct, but I'd like to see something that actually backs that up.

[Widewing]

Originally posted by Karnak
What should the Fw190A-5's roll rate be at 300mph?  Keep in mind that Widewing's test was not of sustained roll rate.  Widewing's test was not at all of the max roll rate.  Isn't there supposed to be a 190 FM revision coming in any case?

My roll rate tests were done for a single revolution as this is more realistic of combat. A single roll will include delays associated with resistance to rolling (overcoming inertia). 300 mph was used simply as a common baseline, without regard to determining best roll speeds for each type.

As to the 190A-5 being slower than it should be, it really isn't. In fact, it is very close to NACA's test data for a 190A-4. However, the 190's best roll rate is attained below 300 mph, as this speed is on the backside of the roll curve. I tested the 190A-5 at slightly lower speeds and it was considerable faster. Ideally, the best speed for the 190 is around 280 mph. I tested at 290 and 280 just to verify the curve seen below. All numbers rounded to closest non-fractional, either up or down.

290 mph, 2,000 feet, 50% fuel:
Right: 137 degrees
Left: 140 degrees

280 mph, 2,000 feet, 50% fuel:
Right: 140 degrees
Left: 144 degrees



My regards,

Widewing

[Widewing]

I tested the Spitfire Mk.VIII for roll at various speeds beginning at 150 mph and in increments of 50 mph up to 400 mph.

2,000 feet, 50% fuel

150 mph:
Right: 65 degrees
Left: 72 degrees

200 mph:
Right: 85 degrees
Left: 93 degrees

250 mph:
Right: 79 degrees
Left: 87 degrees

300 mph:
Right: 68 degrees
Left: 74 degrees

350 mph:
Right: 52 degrees
Left: 54 degrees

400 mph:
Right: 36 degrees
Left: 37 degrees

Note that as speeds increase, the Mk.VIII suffers from increasing pitch-up when rolling and that requires elevator input to minimize, likely effecting times recorded, and thus rate of roll measurement will have an increased error.

My regards,

Widewing

[Crumpp]

In fact, it is very close to NACA's test data for a 190A-4.

The NACA simply copied the data from the RAE 1231 test of a captured FW-190G series.

In that test the forces exhibited and the behavior of the aircraft do not match the calibration charts found in the aileron adjustment regulations.

Even the test pilot noted something was wrong.

There are several threads which showed the documentation.

The NACA curves and RAE 1231 represent an FW190 with ailerons out of adjustment and are a very good measurement of "at least" performance.  They certainly do not represent average or best performance.

All the best,

Crumpp

[Widewing]

Originally posted by Crumpp
The NACA simply copied the data from the RAE 1231 test of a captured FW-190G series.

In that test the forces exhibited and the behavior of the aircraft do not match the calibration charts found in the aileron adjustment regulations.

Even the test pilot noted something was wrong.

There are several threads which showed the documentation.

The NACA curves and RAE 1231 represent an FW190 with ailerons out of adjustment and are a very good measurement of "at least" performance.  They certainly do not represent average or best performance.

All the best,

Crumpp

Is this the data you are referring to in NACA report 868?



My regards,

Widewing

[Crumpp]

Yep

You want the whole report?

[Widewing]

Originally posted by Crumpp
Yep

You want the whole report?

I have it, but thanks anyway...

Gotta tell ya, that Typhoon rolls like a fat man sleeping on a 2x4....

My regards,

Widewing

[Crumpp]

Gotta tell ya, that Typhoon rolls like a fat man sleeping on a 2x4....

Yeah, from what I understand the Typhoon had a problem with the wing design nullifying much of the aileron input.  

You have to love that Napier Sabre though.

All the best,

Crumpp

[Angus]

Here's a little input.
For Kurfurst:
The quote from Henshaw regards a FLICK roll, not actual roll rate and this has been pointed out to you at least 2 times before.

Then the second thing. The aileron control was improved on the Mk VIII to increase stiffness It has something to do with the hinges. It's in Quill's book and I can find it - in fact I posted it a couple of weeks back.

The third thing was posted somewhere above but is needed to be kept awake. Our Mk VIII does NOT have the extended wing.

If anything the VIII should probably roll better than the Mk IX.

[Crumpp]

The quote from Henshaw regards a FLICK roll, not actual roll rate and this has been pointed out to you at least 2 times before.

I think this is one of the things AH does not model well.  All the aircraft have computer precision rolls based on their roll rate not the ADM standard.  

Some aircraft simply did not begin to respond to aileron input as fast as others even though their roll rates where very similar.  This is why you do not see "agility" as a very important characteristic for a fight in Aces High.  In reality it was much more important than sustained turning ability for air to air combat.

All the best,

Crumpp

[Angus]

If the roll rate, say doing a half roll ends up at the same time, how can this be a big factor?
One aircraft starting the roll a bit more crisply, the other (given that it does the half roll in the same speed) catching it.