Stability and Control characteristics of the Early Mark Spitfires

[Crumpp]

What is the pilot to do if the airplane does not recover by 5000 feet?

[Crumpp]

We will simply forget the fact the Spitfire 'never' picked up the reputation you are seeking here

Wow, the instability only existed in the early marks.

Not all Spitfires were Mk I, II, or early Va's.

However ALL Spitfires were fixed with the addition of bob-weights or other design changes to eliminate the instability.

[IvanK]

Originally Posted by Crumpp

What is the pilot to do if the airplane does not recover by 5000 feet?

It doesn't actually say must be recovered by 5000feet it says recovery must be initiated by 5000feet. Its minimum altitude guidance to the pilot implying that up to 5000feet might be required for full spin recovery.

[Crumpp]

Right Ivan....

Did you read the recovery characteristics??

Again, answer the question.

What is the pilot to do if recovery does not begin by 5000 feet?

[IvanK]

Crummp read the exact words. "Recovery must be STARTED not lower than 5000 feet" !!!!

Its like in any aeroplane that the pilot has a means of escape, (Ejection seat or parachute). Its a judgement call if out of control there comes a time where the pilot must decide stick with it and attempt a recovery or step over the side.

Did you read the AVIA test reports on spinning behaviour posted earlier ... ?

[DC338]

Originally Posted by Crumpp

Right Ivan....

Did you read the recovery characteristics??

Again, answer the question.

What is the pilot to do if recovery does not begin by 5000 feet?

The simple answer is continue with the spin recovery that you have already initiated and you should come out of the spin in the next turn or so. Allowing you sufficient room to pull out.

[camber]

Robtek and Manu,

Thanks for participating and sorry if you feel like you are being whacked in the face repeatedly by a 1/24 scale Spitfire.

I have an emotional connection to the Spit, I always go and give my one a pat (Mk19) whenever I am back in my home city (Perth, Aus), and marvel at it's very odd rudder trim tab.

Despite that, I agree with most of what you say, as I agree with the core of Crumpp's argument as I see it:

The early marks of Spitfire had specific measured control characteristics, involving slight longitudinal instability, neutral stick stability and light control forces. These should be implemented as well as possible in simulation.

I don't see anyone disagreeing with that actually. I am disappointed that it is tricky to even acheive a high speed stall in current CloD Spitfires.

Crumpps qualitative interpretation on top of that that the Spit stability is a large weakness (reading back through the thread it still seems clear to me but not so much in the original post) is not supportable, unless you can legalistically exclude all opinions by pilots, which are legion. Especially when the NACA standard is admissable, which unlike the stability data it is based on, is an expert but qualitative judgement on top.

That said there are some odd side issues added in by Crumpp, like the assertion that buffet is effectively binary in the sense that either the Spitfire is out of the buffet, or stuck in a hard buffet with a massive turn degredation. This does not seem to fit with the historical record or IvanK's and Glider's flight experience of buffet onset sensing than unloading slightly.

The MkV bobweight attributed as a cure for dangerous instability in MkI and II is not supported by the historical evidence as I see it.

I could certainly believe that accidental spins out of combat turns occurred often in the Spitfire, as they are amply documented. Recovery is clearly straightforward, which should give one caution of using instructions in Pilot's notes as proof that certain actions endanger the Spitfire more than other fighters of the time.

I could certainly believe that Spit instability decreased it's ability as a gun platform, as this is supported by the historical record.

I really don't think that arguing as if the other side have had a special meeting and share all the same arguments is constructive. It's a shame though, the disscussion moderates always disappear (at least not literally, like in a civil war ), or get mad and become extremists, leaving the latter as the last men standing.

I also wish the mods could have a script that deletes any post that use the eyes rolling icon. And perhaps over a certain% of bold. But not smileys

camber

[DC338]

The problem that we are faced with despite 46 pages of post is how you would implement these "issues" In a game that you can modify control curves etc. Yes the spit should be sensitive in pitch and less sensitive in roll but with adjustable curves how you do it. Also we have joystick that are not even close in length and therefore throw compared to a real life aircraft. We also cannot sense G in game or for those without force feedback any hint of buffet. We can ask for aircraft that perform in speed, turn rate, RoC, etc but how do you simulate control feel? Even in multi-million $ sims that I have flown control feel in the sim is not the same as in the aircraft, and these are aircraft that have artificial feel as part of the control system.

We all want accuracy but how do we achieve it? Quantifiable performance (speed, RoC's etc) is much more important to get right to begin with than control feel. Get aircraft (be they blue or red) first to perform to the numbers (which we don't have at present.) The you can deal with secondary issues.

At the end of the day the spitfire had a good reputation amongst those who flew it in combat. It was not an "ensign eliminator" or a "son of a Bi%^ch second class" it may have had some issues with longitudinal stability, yet was known as an aircraft that was a joy to fly.

[camber]

Originally Posted by DC338

The problem that we are faced with despite 46 pages of post is how you would implement these "issues" In a game that you can modify control curves etc.

I totally agree, not only is it technically questionable how one could do it, but I consider the chance of devs attempting it is nil. I don't mean that as a criticism of the devs. I do think some improvements could be made within the limitations of different control gear, response curves etc.

So it seemed to me that the thread was more a historical discussion of Spitfire handling, which has thrown up a range of interesting historical sources. Somewhere along the lines of, how would the perfect sim model stability?

camber

[CaptainDoggles]

Originally Posted by DC338

The problem that we are faced with despite 46 pages of post is how you would implement these "issues" In a game that you can modify control curves etc.

No matter how you set up your curves, you'd still need to reduce pressure on the stick to avoid the aircraft tightening up the turn by itself.

That right there would go a long way towards the correct "feel".