PJ2, chuks and others: thank you for your many insights. This really has turned into a remarkable thread altogether. As an humble GA bystander, I'm finding it about as insightful and informative as any that I can recall - on this forum or any other. Hats off to you guys. Personally I find it most reassuring, the level of introspection and cool, rigorous analysis on display - wish'd I saw more of it in other walks of life. No, there aren't any easy answers - that's why commercial aviation is such a fine profession.
On with the motley ....