Stability and Control characteristics of the Early Mark Spitfires

[CaptainDoggles]

Originally Posted by Crumpp

Negative stability is divergent. Co-efficient of moment and Co-efficient of lift have an inverse relationship in a stable airplane. You can look at the Co-efficient of moment against Co-efficient of Lift plots in the other report Lane posted and see the slope is positive.

This is what I got from the report as well, but what I wasn't sure about was the difference between columns 1 and 2. Did they just run 2 trials at each flight condition and those are the results?

Additionally, it seems odd to me that in the "Engine Off" case, it appears stable in trials 5, 6, and 7 but #8 is not stable. All the other variable appear to be the same (flaps+gear are up, altitude is the same, trim set to -7.5).

Anybody know why that would be the case?