"What I found is that the SpitVII, SpitXIV and SpitXVI will all break wings at 570 mph @ 6.5g. In contrast, the SpitIX does not do so. It requires 7g to break a wing at that speed. It's simply a function of weight. The heavier aircraft will impart greater load at any specific g loading. The greater the weight, the lower the g value required to attain a load that results in failure.
On the other hand, I can't break an F6F-5 under the same speed and g loading."
F6F had a slightly thicker profile when compared to relative thickness of Spitfire's wing.
F6F: NACA 23015.6 / NACA 23009
Spit: NACA 2213 / NACA 2209.4
It is possible that the wing of F6F needed to be somewhat stiffer since the landing gear is further in the wings and they need to endure carrier landings with weight of 12,000 lbs where as the Spit had the landing gear attached nearer to fuselage with weight of 8,000 lbs and less wingloading so the structure could have been slightly lighter.
190s had small stiff wings and a reputation of being able to pull tremendous amounts of Gs without wing failures and even some Ta's still had the shorter wing. The G loading may build up quite abruptly along the wing span being heaviest a the tip, and of course if it does not bend it breaks and that is why I think the Ta with long wings surely had smaller load limit than those of the short span wings.
I think it is strange if the Spit loses a wing totally since the spar was designed to endure lots of dynamic load without breaking so the designers knew that the large wing would be under tremendous loads in high speed maneuvers. The drawback is that the tubular spar structure is quite heavy so AFAIK it did not expand all the way to the tip. Did the Spits IRL really shred off all the wing or just parts of it?
-C+