Stability and Control characteristics of the Early Mark Spitfires

[NZtyphoon]

Originally Posted by Crumpp

Are we really gonna have this conversation??

Originally Posted by Crumpp

JtD, they flat out state the stick fixed longitudinal stability is unacceptable. That is the NACA, not me.

Why do you think bob-weights were added to the design to fix the longitudinal stability?

I can't help it if you're confused: the-reason-inertia-weights-were-introduced-was-because-Spitfire Vs-were-being-badly-loaded-at-an-operational-level-in-1942. As more operational equipment was introduced some squadrons were ignoring the loading diagrams. It had nothing to do with the NACA report.

[Crumpp]

it was statistically established that, as soon as the longitudinal stability of the Spitfire was thus brought under control

Why don't you read the Operating notes for any early mark Spitfire.

"longitudinal instability" is used often....

I am sure the Spitfire Mark V increase in weight and speed caused an unmistakeable as well as difficult to ignore increase in in-flight break ups.

[NZtyphoon]

Originally Posted by Crumpp

I am sure the Spitfire Mark V increase in weight and speed caused an unmistakeable as well as difficult to ignore increase in in-flight break ups.

Nope, you are quoting well out of context: what caused some break-ups was poor loading by the squadrons, as was explained by Jeffrey Quill:

Originally Posted by NZtyphoon

Quill
"In general configuration the Mk I and Mk II production aeroplanes were almost identical to the prototype and so there was no problem with their stability." (231-232)

"Therefore, for each sub-variant of the Mk V detailed instructions for the correct loading of the aircraft were issued to squadrons....However the importance of these loading instructions was not generally appreciated in squadrons and in the daily round of operational activity they tended to be disregarded." Once the bobweights had been introduced and, in later marks, the modified mass balances on the elevators...it was statistically established that, as soon as the longitudinal stability of the Spitfire was thus brought under control, the problem of the unexplained breakings-up of aircraft in mid-air,...'softly and suddenly vanished away'." (page 238 )