Here's a link to how the legendary Neil Williams managed to keep flying (and living!) after a catastrophic wing spar failure in his Zlin in 1970. Sadly Neil died some years later flying a Spanish He-111 (CASA 2.111) into a mountain
His two books "Airbourne" and "Aerobatics" I highly recommend.
http://www.aerobatics.org.uk/repeats/zl ... ailure.htm
http://en.wikipedia.org/wiki/Neil_Williams_(pilot)