"expresstechonsite" wrote in message
And now for the REALLLY stupid question... what about using PVC tubing?
I know that PVC is much more flexible than steel or aluminum tube, but
could it work? The reason I ask is because I keep thinking that if we
once made airframes out of wood, then wouldn't PVC be just about as
strong and more durable (long lasting?).

Wood has excellent fatigue properties. Airplanes vibrate a lot. PVC could be
engineered to accept the loads of a light plane, though it wouldn't be as
efficient and it would probably crack in the near future at an inopportune
time.

D.