Stability and Control characteristics of the Early Mark Spitfires

[Crumpp]

you are quoting well out of context

No I am not. You don't seem to understand the effect of weight and speed on airframe loads.

I have the entire report and will post it as part of the bugtracker.

Once again, you are going down the rabbit hole.

[macro]

Originally Posted by IvanK

So then Mr Crumpp exactly what is wrong stability wise with the IL2 CLOD Spitfire MI I or II Ver 1.06.17582+Hot Fix

Thats what i want to know.

[winny]

Originally Posted by IvanK

So then Mr Crumpp exactly what is wrong stability wise with the IL2 CLOD Spitfire MI I or II Ver 1.06.17582+Hot Fix

And this, gentlemen, is the 64,000 dollar question...

[JtD]

Originally Posted by Crumpp

The other part is that they do say the airplane is unstable.

NACA says: "... the small static longitudinal stability of the Spitfire...". Not unstable...it's there in black and white, first sentence of the relevant paragraph. And, again, the stick force gradient and the elevator angle gradient were both found to be positive.

[fruitbat]

Originally Posted by IvanK

So then Mr Crumpp exactly what is wrong stability wise with the IL2 CLOD Spitfire MI I or II Ver 1.06.17582+Hot Fix

Yes, I'm curious to.

And how has it been tested?

[Sandstone]

Originally Posted by IvanK

So then Mr Crumpp exactly what is wrong stability wise with the IL2 CLOD Spitfire MI I or II Ver 1.06.17582+Hot Fix

Indeed.

Crumpp, you should answer this one.

[NZtyphoon]

Originally Posted by Crumpp

No I am not. You don't seem to understand the effect of weight and speed on airframe loads.

I have the entire report and will post it as part of the bugtracker.

Once again, you are going down the rabbit hole.

The only one going down a rabbit hole is Crumpp, who doesn't seem to understand the cause and effect of bad cg loading on a basically sound design and now assumes that the Spitfire V was prone to break up because it had taken on extra weight and could fly faster.

And what report is Crumpp going to post?

Originally Posted by IvanK

So then Mr Crumpp exactly what is wrong stability wise with the IL2 CLOD Spitfire MI I or II Ver 1.06.17582+Hot Fix

Second question, how exactly can Crumpp's bugtracker replicate the longitudinal stability characteristics Crumpp thinks the CLOD Spitfire I & II should have, when there is no option for rough air conditions?

[Crumpp]

NACA says: "... the small static longitudinal stability of the Spitfire...". Not unstable...

[JtD]

You keep quoting the summary as if it was the only and complete assessment, but it is not. The paragraph dealing with stability as such already gives a more detailed description, that being in general agreement with the summary, but more specific in that "The stability was essentially neutral in all flap-up, power-on conditions of flight except at low speeds, where some rearward motion of the stick occurred." And if we look for further detail on behaviour in accelerated flight, we find "the small static longitudinal stability of the Spitfire" I quoted. And this is proven by stick travel and stick force gradients, for anyone to see.

This doesn't change the fact that NACA found the plane neutral with power off and unstable with flaps down, but this is of no interested in power on accelerated flight.

If you want to sell instability to me, or anyone else who's got a good understanding of the matter, you'll need to explain how both of the above gradients can be positive in an unstable aircraft and how it was possible to fly the smooth stick fixed turns as shown in figures 17 and 18. Repeating the summary yet another time will not do the trick.

I think there's no point in submitting anything to the bugtracker before this has been clarified.

[Glider]

I think its worth remembering that Handling isn't a precise science. Many aircraft have been designed by trained designers well schooled in the theory and science. Yet all at one point or another have produced aircraft that handled poorly.
Any theory needs to be supported by comments from test pilots and others to support that view.

This is something that has often been requested but has yet to be shown apart from one attempt (posting 321 page 33) which backfired.