Stability and Control characteristics of the Early Mark Spitfires

[bongodriver]

In otherwords, the early mark Spitfire was not a hands off aircraft. Left to its own devices, it would eventually destroy itself without pilot input in conditions it was divergent.

'NO' mark of spitfire was 'hands off', nor for that matter was 'any' aircraft of the time, have you really raised a thread with all the guff you posted at the beginning just to prove the aircraft would 'eventually' 'if' left 'unchecked' destroy itself? what do you think pilots do? they control the aircraft.

Please tell me this has all been just a bad joke, I ended up banned for doing nothing different to anyone else on this thread.

[FS~Phat]

Gents time to all step away from the keyboard a bit and try and keep it from being personal. I dont want to have to lock the thread but I will if you cant all play nice!

And im not singling anyone out, your all as bad as one another in different ways. Which often happens with us passionate lot but please have a bit of humility and humour in your discussions as if you were a couple mates having a good old disagreement over a beer at the pub! If you can discuss with that kind of banter and respect it will be more fun for everyone. REMEMBER NO ONE IS WRONG OR RIGHT im 99% of these discussions, it is discussion of opinion. Facts can be interpreted differently or differing accounts can be made for just about every claim or published article ever made on the spit, the 109 and most of the era's aircraft. Please remember you are not automatically right just because you found something on the "interweb". None of us are experts in testing and we are presenting and interpreting data without the proper training to do so.

So have I made it clear we are all here to learn and discuss and not make things personal, and also try not to take everything personally???
Sometimes its hard I know but please give it go gents.

[macro]

My2 pennies.
I diidnt think any fighter was hans off at the time?
If i went to make a cuppa during flight i would most likely come back to a burning wreck no matter the plane i was flying.

We need structural damage modelling for all planes to stop unrealistic manouvers unger high g's. Is there bug tracker for this? Maybe a more sensitve elevator as this is well documented

Not going to comment on the rest as, to be frank, i dont understand it!

[Glider]

Originally Posted by Crumpp

In otherwords, the early mark Spitfire was not a hands off aircraft. Left to its own devices, it would eventually destroy itself without pilot input in conditions it was divergent.

Crumpp
Can you name any aircraft, of any type, in any airforce, that was hands free during WW2, ie wouldn't eventually destroy itself without pilot input in conditions it was divergent?

[Osprey]

V1 doodlebug

[41Sqn_Banks]

I don't know about 'hand off' but there were aircraft that couldn't even be flown 'feet off'. Must have been total crap planes ...

[Glider]

Originally Posted by Osprey

V1 doodlebug

Even here there were a fair few failures.

All I am asking Crumpp to do is support/clarify a view.
a) If he believes that it was a common trait amongst WW2 aircraft that aircraft were not hands free then why single out the Spit for critisism.

or

b)If the Spit is an unusual example, then he should be able to nominate one that was hands free.

Pretty simple really.

[Crumpp]

JtD Says:
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 .

You're repeating what I said yet you try to make it sound as if you disagree with me. Why?

Because I do disagree with you. You confuse apples and oranges between long period oscillations with stick free behaviors and the short period the NACA measured.

The RAE was not stupid. They measured the stick free behavior for a valid reason. You can quickly look at the those graphs to see the Spitfire has positive static and negative dynamic stability stick free. It shows the work load required of the pilot and the ability of the aircraft to maintain equilibrium. The Spitfire was neutral or divergent.

The NACA did not even consider long period oscillation. They only considered short period. Yes, it does matter. It matters so much, it was promptly corrected in the design.

NzTyphoon:

Absolute Nonsense...

Everything is "absolute nonsense" to you, yet you confuse so many things. My advice is to look at the exact conditions and take each statement one at time. It is a scientific report and the language is specific.

You might see that it all fits together and the NACA knew what they were doing. Otherwise, we are forced to concluded that you know more than they do regarding stability and control. I kind of doubt it, though.

Here is a few clues:

1. Guns ports open.....gun ports closed.....(drag picture)

2. Violent pre-stall buffet is not stall motions. It is the the "violent shudder" as noted in the Operating Notes as well as measured data from the NACA

we are presenting and interpreting data without the proper training to do so.

Speak for yourself!

I worked very hard, investing both time and money for my education. Stability and control was covered and testable.

Can you name any aircraft, of any type, in any airforce, that was hands free during WW2, ie wouldn't eventually destroy itself without pilot input in conditions it was divergent?

Most aircraft are not positive statically stable and negative dynamically stable stick free. It is an unacceptable characteristic.

It is a situation where the the aircraft moves toward the trim condition but increases the force on the axis of motion so that it overshoots the mark. The key is our force is increasing with each oscillation. This causes the motion over time to grow larger and the velocity along the axis of motion to increase. Eventually, the forces will overload the aircraft and it will destroy itself.

[Crumpp]

If the Spit is an unusual example, then he should be able to nominate one that was hands free.

F6F, Hurricane Mk I and Mk II, F4F, Bf-109, FW-190, A6M, and the list goes on...

Glider,

Most aircraft are not positive statically stable and negative dynamically stable stick free. It is an unacceptable characteristic.

[bongodriver]

Most aircraft are not positive statically stable

Really?.....are you sure?

Positive Static Stability—The initial tendency of the airplane to return to the original state of equilibrium after being disturbed.

Static Stability is measured by Short period oscilations.

This sounds like 'most' aircraft to me and is certainly what I have experienced, the Spitfire was neutraly staticaly stable which is what gave it the light controls.

Dynamic stability is shown by measuring the long period oscilation, in the Spitfires case it was 'slightly' longitudinaly unstable and this is is what contributed to the maneuverability of the spitfire.