I'm really surprised that all it takes to be declared qualified is the signature of someone else who's qualified. That leaves lots of room for slippage and social pressure, like the dip you mention. It also leaves no one specifically responsible for the crew's level of qualification. A cynic might say that was the point of the system: we know this is going to fail, so make sure no one is directly in the line of fire when the shit cannon goes off.
There is generally written testing involved, along with a multi-person board/interview that is a direct knowledge test under that inherent stress of face to face.
I'm really surprised that all it takes to be declared qualified is the signature of someone else who's qualified. That leaves lots of room for slippage and social pressure, like the dip you mention. It also leaves no one specifically responsible for the crew's level of qualification. A cynic might say that was the point of the system: we know this is going to fail, so make sure no one is directly in the line of fire when the shit cannon goes off.