Of course you are right LOMCEVAC. I was referring to the primary airframe strength, but there are all sorts of other bits like engine mounts, seats, batteries, baggage tie-downs which are stressed to N1, and at best it would smart a bit if those went, even if the wings and fuselage do hold together.
Pulling two POH off the shelf, I note that the PA28 and C152 both show variable values of Va, which a quick back-of-envelope sum indicates that are a function of constant N1.
Which raises an interesting philosophical point. A great many aircraft have Va determined at MTOW and placarded, but actually it should vary with weight in a way that, frankly, very few pilots will bother to work out (and I suspect just as few are taught to, my PA-28-161 POH for example refers to linear interpolation - now I know what that means but suspect strongly that I'm in the minority). An argument could readily be made that this is dangerous and we should perhaps in such aircraft standardise on the lower value of Va, say calculated at minimum permitted flight weight?
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