BA vs RN
timzsta, I believe that BA has flown a few more miles in four-donks than RN ever dreamed of. The 747's systems are well-proven to prevent "creeping failure" i.e. a cascading of individual failures (lack of redundancy) leading to an accident. Trend condition monitoring of engines gives a better assessment of the health of the remaining three than any military aircraft ever had.
Illigitum non carborundum.