From someone who is not certainly not a professional, and rarely a passenger, but interested in aviation: has there been many accidents when intoxication has been the main factor?
In all seriousness, the investigations into air crashes seem to most frequently point up equipment failure (something breaks unexpectedly), then human error (in the sense of flight deck failing to respond appropriately to the warnings when things have already started to go wrong), and human error in the sense of poor maintenance by the airline.
When has there been an accident primarily due to intoxication?