Originally Posted by
Eric Page
The issue is this: it's up to the builder to set the maximum gross weight on the airworthiness certificate application. If the inspector isn't intimately familiar with the type, he may just accept whatever the builder puts on the form as long as it seems reasonable for the plane he's inspecting. The fact that the SkyRaider you're looking at was issued an airworthiness certificate at 1,200#, and has been flown at that weight, does not necessarily mean that it's been engineered and modified properly for the higher weight.
For example, I have a Series 5 Kitfox that's supposed to be 1,400#, but the later production units went up to 1,550#. I could easily list the higher weight on my airworthiness application and it's likely that no one would be the wiser. I'd get an airworthiness certificate at the higher weight just by declaring it so, and without making any of the necessary structural modifications. The airplane would look more useful on paper, but would it be safe?