Originally Posted by
Chu Chu
I've read about light aircraft with tubular steel frames that are sealed and pressurized. As long as the frame stays pressurized, you know there are no cracks (or at least no full-thickness ones).
Been around tube framed aircraft a long time, even own one, and I have not heard of pressurizing structural tubing. So, if it's true what you say that the pressurization is a check on cracks, how exactly does that work? Is there also a pressure gauge on each tubing segment? If not, how does one tell if the tube remains pressurized or not?