Originally posted by Charge
"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+
What hurts the Spitfires at high speeds are the extremely sensitive elevators, which are well modeled in the FM.
At 575 mph, you cannot get enough elevator displacement in the 190s/152 to load the airframe enough to break the wings. Likewise for the P-51s. In these types, you pull back the stick to its stops, but you can't pull to blackout until you bleed off considerable speed. In contrast, you can get more than enough elevator displacement in the Spitfires to instantly blackout and strip off the wings in the blink of an eye.
It's simply a matter of fully knowing your airplane. I'd wager than the majority of players have absolutely no clue why some aircraft suffer airframe failures and other do not. I'll also bet that very few know how to avoid that problem. Far too many players just slam the stick about with abandon. I constantly tell pilots that smooth is always better. You not only avoid over-stressing the airframe, you also conserve E. "Slow is smooth and smooth is fast."
As to the F6F-5, I suppose that HTC modeled it based upon the design limits. Both the F6F and F4F demonstrated the ability to withstand g loads of up to 12g and in one well documented case, 13g. These loads were measured during max performance pullouts. In several cases, the engine A frames bent slightly, but the airframe itself sustained no damage. Grumman "over-engineered" their aircraft, being willing to trade a bit of performance for shear strength. That was the crux of their design philosophy; "build them simple, build them strong" - Leroy Grumman.
My regards,
Widewing
