I once tried to suggest to an instructor that (Relatively) the air that a model flies in is denser than around a full size aircraft. The idea was poo pooed, "don't be stupid it's all the same air".
Another instructor described an event where he and another instructor took a T21 to several thousand ft and set up the phugoid stall/self recovery to see how far it would go.
The stall and recovery got progressively steeper until it suddenly bunted and flipped upside down. At which point they pulled to recover and rolled out right side up.
Not as safe an aircraft as was thought!
Last edited by Crash one; 24th Apr 2018 at 13:10.