I don't know. A lot of the problems that occured on planes were hard to predict even though they go through the rigorous process you mention. Battery fire on B7

I don't know. A lot of the problems that occured on planes were hard to predict even though they go through the rigorous process you mention. Battery fire on B787. Cargo door on DC10. Engine leaks on A380, etc. These are all quality/design issues that were not predicted.