Not even JT will show an example
I refer to you #173 - I made no claims about this or that aircraft for specifics. ANY aircraft will break if you overload it enough.
Megan (#184) makes a telling observation losing a wing in a beat up is not that unusual, there is video of a Mosquito losing its wing doing the same. Keep in mind that he is a very experienced and knowledgeable pilot, apart from being an all-round pleasant sort of chap. I think back, occasionally, to the first time I had a ride in a light aircraft, shortly before starting my PPL training. Up at Cessnock, where I lived at the time, young chap with his wife in the front seat of the C172 and me in the back. Now, I was a high school student with not much knowledge of aircraft and thought it all was a great bit of fun. These days, I think back and wonder if that fellow had any idea of just how stupid he was ?
The problem for pilots is a general lack of detailed knowledge sufficient to have a basic understanding of what is a reasonable load to ask the aircraft to sustain.
there must be a quick 'rule of thumb' calculation of IAS Vo for the range of weights of the aircraft.
There is - I gave it in my post(s). I can train any Joe Blogs to run those calculations competently in, probably, 10-15 minutes, complete with practice exercises in a tutorial situation. If I get into an unfamiliar Type, it will take me only a couple of minutes to have the numbers in the back of the head.
Starting point is to check the value for n in the POH limitations section. If you want to omit the PEC bit that probably isn't going to make all that much difference as the error will be reasonably low. The lower speed is appropriate for rough and tumble conditions so you could be a bit rubbery with that one.
Why do you opine that there is a problem ?
A problem (I see) for pilots is that many didn't bother acquiring anything more than the absolute lowest level of knowledge to pass the exams and get the licence. Some have the greatest trouble running the simplest of fuel required calculations.
I really shake my head when I see the plethora of places where one can get a whole lot of practice exam questions sufficient, eventually, to scrape through the exam without opening a text book. Then there is the oft-seen comment that one just does a data dump after the exam, anyway. One should be able to rely on the flight test examiner's quizzing the candidate sufficient to establish that there is a reasonable basis for knowledge ... but, sometimes, I wonder ?
What hope do these kids have ?