So how many twin engine aircraft have been lost due to only having two engines? How does the risk analysis change if you compare an older generation four engine aircraft that is poorly maintained and flown by poorly trained crew to a modern two engine type with good maintenance history and well trained crew? Yes, ETOPs is based on probability, but isn't any safety system? If we were to try to eliminate all risk, regardless of cost, wouldn't air travel become unaffordable? I think a rather outspoken former Chairman of the CAA made this very point about 'affordable safety'.
