The 'Great Debate' - Spitfire vs BF109

[Crumpp]

The best are borderline unstable as are fighters,

It is a complete fallacy that manueverability and stability are linked by an inverse relationship.

"Just statically stable" has nothing in common with "borderline unstable".

[Glider]

Originally Posted by Crumpp

It is a complete fallacy that manueverability and stability are linked by an inverse relationship.

"Just statically stable" has nothing in common with "borderline unstable".

Sorry Crumpp but this statement is totally wrong. A Ground Attack aircraft is normally very stable as it spends a lot of time at very low altitude where the air is rougher. However it is normally less responsive to inputs from the controls as the wing is designed to soak up rough air.

A fighter has a lighter touch and the reponse times are more immediate.

To use the Glider examples the Twin Astir was used to teach basic aerobatics but it was hard work. Most of the training was done on a K21 a very popular glider which incidently was almost impossible to spin. When I did an advanced course we used a Fox glider, a dedicated aerobatic glider. This was very sensitive and needed a gentle touch.

I have no doubt that all three were technically stable but the dedicated aerobatic Fox was far more sensitive, and responded to any input.

I work on the basis that the SPitfire was like other fighters the equal of the Fox.

[TomcatViP]

Glider, if they wanted to make it unstable or even neutraly stable, they would hve taken great care that the ailerons had the same sensitivity. It's quite unpleasant to have to make wide move in the roll axis when you've got a narrow travel range longitudinally.

The fact is that many bi-plans were marginally stable (inherent to their shape and short fuselage). Perhaps that experienced professional military pilots with years of flying the biplans in the 30's didn't bother that much that Spit annoying characteristic in regard of the general perfs improvement.

[Glider]

Tomcat
Find any pilot of any nation including German ones, who found the Spitfire difficult or unpleasent to fly. If it was as difficult as people are making out you should be able to find someone.

Just remember that Molders described the SPitfire as being faultless in a turn and childishly easy to take off and land. He found it much easier that the Me109.

Stability depends on what you want out of the aircraft. As I tried to show with the different Gliders, the dedicated aerobatic Fox was far more sensitive than the others. A Fighter needs to be more sensative than any other type of fighting machine because of what it does.
This goes back to the first air combats in WW1. Generally speaking the first RFC fighting aircraft were too stable and couldn't mix it with the German fighters. This trend was broken with later fighters until the Camel which was probably too far the other way. Even here the establishment SE5a was more stable than the Camel. Stability is't one measurement, there are degrees of stability. Many bi-plans were marginally stable as you say, but many were very stable it depended what you wanted out of the design.

I admit that I don't understand your statement they would hve taken great care that the ailerons had the same sensitivity The ailerons are the same in each wing, but its late and I might be missing something obvious.

[TomcatViP]

Originally Posted by Glider

Tomcat
Find any pilot of any nation including German ones, who found the Spitfire difficult or unpleasent to fly. If it was as difficult as people are making out you should be able to find someone.

Naca & RAE curves describe instrumented flights were the test pilot had to follow a predetermined trajectory. Nothing like what most of the fighter pilot will try to do.

Still it is interesting that it give us an indication that the ctrls were not the one we have in the sim where the Spitfire act like an F18.

Attention to details and imperfections are what makes a great sim.

Originally Posted by Glider

Molders described the SPitfire as being faultless in a turn and childishly easy to take off and land. He found it much easier that the Me109.

I hve always said that I do believe that the 109 was more difficult to master than the Spit. It's an evidence for me.

What you told us about your experience in gliders is interesting. Thank you for the feed-back.

Originally Posted by Glider

I admit that I don't understand your statement they would hve taken great care that the ailerons had the same sensitivity The ailerons are the same in each wing, but its late and I might be missing something obvious.

I was talking of the travel range in roll that shld be more or less the same as the one in pitch -ie control harmonization - sry for my bad English

It would be interesting (and relatively easy) to hve it implemented in the Spit model.

[II./JG1_Wilcke]

Originally Posted by TomcatViP

Naca & RAE curves describe instrumented flights were the test pilot had to follow a predetermined trajectory. Nothing like what most of the fighter pilot will try to do.

Still it is interesting that it give us an indication that the ctrls were not the one we have in the sim where the Spitfire act like an F18.

Attention to details and imperfections are what makes a great sim.



I hve always said that I do believe that the 109 was more difficult to master than the Spit. It's an evidence for me.

What you told us about your experience in gliders is interesting. Thank you for the feed-back.



I was talking of the travel range in roll that shld be more or less the same as the one in pitch -ie control harmonization - sry for my bad English

It would be interesting (and relatively easy) to hve it implemented in the Spit model.

That is my biggest take away from all this work and research. The fact being that these sims allow us a sneak peak into 'what it must have been like', and thats about it really. To really simulate the inate virtues and foibles of all these airframes along with all the other vagaries inherent in driving a wing in atmosphere is I think at this point in time asking to much from any sim developer.

Cannot wait to read the 109 information!

Well done!

[fruitbat]

Originally Posted by II./JG1_Wilcke

Cannot wait to read the 109 information!

Well done!

don't bank on it.

[Crumpp]

Originally Posted by Glider

Tomcat
Find any pilot of any nation including German ones, who found the Spitfire difficult or unpleasent to fly. If it was as difficult as people are making out you should be able to find someone.

Just remember that Molders described the SPitfire as being faultless in a turn and childishly easy to take off and land. He found it much easier that the Me109.

Stability depends on what you want out of the aircraft. As I tried to show with the different Gliders, the dedicated aerobatic Fox was far more sensitive than the others. A Fighter needs to be more sensative than any other type of fighting machine because of what it does.
This goes back to the first air combats in WW1. Generally speaking the first RFC fighting aircraft were too stable and couldn't mix it with the German fighters. This trend was broken with later fighters until the Camel which was probably too far the other way. Even here the establishment SE5a was more stable than the Camel. Stability is't one measurement, there are degrees of stability. Many bi-plans were marginally stable as you say, but many were very stable it depended what you wanted out of the design.

I admit that I don't understand your statement they would hve taken great care that the ailerons had the same sensitivity The ailerons are the same in each wing, but its late and I might be missing something obvious.

The German report also notes the longitudinal instability. It does NOT note the CG position of the aircraft.

Quick changes of the trajectory along the vertical axis cause especially with the Spitfire load changes around the cranial axis, coming from high longitudinal thrust momemtum, and significantly disturb the aiming.

http://kurfurst.org/Tactical_trials/...g_Aug1940.html

[Glider]

All that proves is that you can have some longitudinal instability and still be faultless in a turn as well as easy to take off and land.

It also says that the Spit wasn't a very steady gun platform