[bongodriver]

NACA shows progressive stick travel and elevator force over lift coefficient and normal load. You are directly contradicting NACA. I'd appreciate if you could point out the chart or table you are basing your conclusion on.

Additionally - the Spitfire stability "failed to meet an accepted requirement". This does not make the stability unacceptable. It may seem to be the same for people unfamiliar with testing and test reports, but it is not. In this case the difference is evident from the fact that the Spitfire was accepted into service with 30+ air forces worldwide, among them the USAAF. This would not have happened had the stability been unacceptable.

+1

it's like adopting a standard where everything has to be purple and then testing something which is green and surprise surprise it fails the purple standard.

This was a test on a MkV, nothing in the test mentions a similarity with earlier models, and the MkV had a different weight and balance.
Was it the Americans that advised the addition of the bob weight?
I believe some RAF units asked for it to be removed so they could have the original flying qualities back, doesn't sound like the original ones were so bad in that case.

This whole thread has been about making a mountain out of a molehill.