The Colditz plane was never used, the prison was liberated before it could be tried out. Some TV company did an experiment a few years ago. They got the old prisoners together, got the plans and built the plane. It would have worked, it flew far enough to get them over the wire and far enough away so they could make a run for it.

Wasnt there one where they used a piece of gym equipment to tunnel out under?

DW at work