On our Aircraft Commander checkout we have the standard question that kind of falls in line with the CA being drunk except in our case you're the AC (CA) and the loadmaster smells of alcohol when you alert for your mission in the morning. The one answer they're looking for in this situation is that you tell him that you suspect he might be under the influence and that he and another crewmember are to proceed directly to the flight doctor while the rest of the crew preflights the aircraft - you also inform command and control that a crewmember might be DNIF (duties not to include flying) and that he is enroute to the flight doc, but you don't tell them of your suspicion. You let the flight doc make the call on whether or not he's drunk. Keeps you as the AC out of hot water both with the UCMJ legalities of accusing someone of a crime and of holding up a mission for something you suspect.