Stability and Control characteristics of the Early Mark Spitfires

[robtek]

Originally Posted by ACE-OF-ACES

So let me see if I understand you correctly..

When a spitfire experiences a high speed stall that results in a 'flick roll' it is undesirable..
When a Fw190 experiences a high speed stall that results in a 'flick roll' it is desirable..

Interesting..

Because we have all heard heard the stories of the German Fw190 pilots that used this technique to evade someone on their six, where they would intentionally cause a high speed stall (acc stall) that would cause the Fw190 to 'flick roll' onto its back to preform a fast split-s maneuver.. Which was a good (desirable) trait as far as the German Fw190 pilots were concerned..

So it appears that you have a double standard..

Spit does it it is a bad thing
Fw190 does it it is a good thing

Which IMHO sounds like you are the one who will just mix the resulting explanations as you like

Are you nuts???

Where in this thread have i ever talked about a 190 and its stall behaviour???

Even Spitfire pilots used this accelerated stall flick roll as a last resort escape maneuvre, i've read somewhere.

It is i. e. bad, when one is pursuing in a spit and it happens, changing the hunter to the prey in the worst case.

Btw, the 190 tactic was especially successful in a low level flight

[robtek]

Originally Posted by JtD

I don't understand why folks are going nuts about the Spitfires longitudinal instability, it wasn't a problem for any pilot or how NACA put it "the well know long period oscillations have no correlation with the handling qualities of an airplane". Basically, it doesn't matter .

Maybe you should define those long period oscillations and make sure that is what the OP is talking about.

Looking on the diagrams i see very short period oscillations.

It is still the target to make it as realistic as possible with proved data.

[6S.Manu]

Originally Posted by ACE-OF-ACES

So let me see if I understand you correctly..

When a spitfire experiences a high speed stall that results in a 'flick roll' it is undesirable..
When a Fw190 experiences a high speed stall that results in a 'flick roll' it is desirable..

Interesting..

Because we have all heard heard the stories of the German Fw190 pilots that used this technique to evade someone on their six, where they would intentionally cause a high speed stall (acc stall) that would cause the Fw190 to 'flick roll' onto its back to preform a fast split-s maneuver.. Which was a good (desirable) trait as far as the German Fw190 pilots were concerned..

So it appears that you have a double standard..

Spit does it it is a bad thing
Fw190 does it it is a good thing

Which IMHO sounds like you are the one who will just mix the resulting explanations as you like

Wow! Tagert, this time you've excelled yourself.

[bongodriver]

Originally Posted by robtek

Maybe you should define those long period oscillations and make sure that is what the OP is talking about.

Looking on the diagrams i see very short period oscillations.

It is still the target to make it as realistic as possible with proved data.

Short period oscilations are measured in seconds.

Wiki I know but it explains it well enough.....

http://en.wikipedia.org/wiki/Aircraft_dynamic_modes

[Crumpp]

JtD.......long period oscillations

Long period Oscillation is not even considered in stability and control. It does not effect any airplane.

Once again, down the rabbit hole we go!!!

[bongodriver]

Originally Posted by Crumpp

Long period Oscillation is not even considered in stability and control. It does not effect any airplane.

Once again, down the rabbit hole we go!!!

Not really, if an aircraft truly has a problem with short period oscilations then it's practically uncontrollable, and we know thats not true of the Spitfire, at worst the problem is 'slight'

[JtD]

Originally Posted by Crumpp

Long period Oscillation is not even considered in stability and control. It does not effect any airplane.

Exactly. And it was the only unstable oscillation with the Spitfire.

[robtek]

Originally Posted by JtD

Exactly. And it was the only unstable oscillation with the Spitfire.

This answer is a try to digress.

We are talking about that it is necessary to move the stick almost completely back to neutral after starting a turn, because of the longitudal slightly negative stability
of the Spitfire (early marks) the turn rate would increase otherwise without further input by the pilot.

We are talking about a very sensitive elevator control, paired with a very short stick travel for large reactions, completed by a relative insensitive aileron control.

We are talking about the former points making it a bit harder to ride the buffet, the excellent stall warning of the Spitfire, without entering the buffet and loosing the turn advantage.

Everything documented and proven.

All this together made the Spitfire to a thoroughbred which needed sensitive hands on the controls.

A plane for the virtuosos, not the ham-fisted.

[bongodriver]

Everything documented and proven.

All this together made the Spitfire to a thoroughbred which needed sensitive hands on the controls.

A plane for the virtuosos, not the ham-fisted.

No, documented and misrepresented.

The Spitfire was famed for being easy to fly 'IN COMBAT' by the very inexperienced pilots of the BoB....

you can embelish it all you want with the 'virtuoso' stuff, that ain't the way it was.

[JtD]

robtek, can you please prepare a list of planes documenting the elevator forces showing the range common to WW2 fighter aircraft and the spots of the various Marks of the Spitfire, depending on the CoG position, on that list? And please also mark the NACA recommendations, on that list.

It would certainly help you getting a perspective. Until you got it, don't waste your time replying to me.

Thereafter, we can talk about what happens say if the pilot does a pullout with a constant stick force in a 109. Will be interesting, too.

Eventually, you may realise that WW2 fighter aircraft in general were nothing for the ham-fisted.