Stability and Control characteristics of the Early Mark Spitfires

[Crumpp]

It was actually addressed in the Spitfire Mk V but the longitudinal instability existed from the beginning.

The RAE did not have stability and control standards. However, the RAE did agree with the NACA even if they did not know it.

They published all the warnings and characteristics of the Longitudinal instability in the Operating Notes. We will get to that.

As for the CG position theory, again, the RAE was in complete agreement with the NACA. They published all the warnings and characteristics of the Longitudinal instability in the Operating Notes.

It is kind of hard to argue that the NACA was incapable of performing a simple weight and balance when the RAE fixed the same issue and published warnings in the Operating Notes. The truth is they just did not know what the NACA was talking about as the stability and control criteria was classified at the time and Gates had not completed his visit.

Gates was well versed in stability and control, however. When presented with the facts and his own testing, he came to the same conclusions as the NACA. That is why the longitudinal instability was addressed with the bob-weights.

I attached the bob-weights which were added to the Spitfire Mk V to correct the longitudinal instability. I also attached an exerpt from Perkins and Hage.