Regrettably one of the most confused cocktails on the planet. When I go to restaurants and bars that claim expertise in mixology, I ask for an Aviation. If the server says they don't have it but the bartender can "create one" for me, I say never mind. The key is the Crème de Violette and Luxardo Maraschino Cherry liqueurs and these are fairly rare in bars. A true Aviation, and trust me, I'm a pilot, is very clear and very blue--like the sky. I frankly prefer to put in a blue cherry (Roland, Wild Berry Flavored #60448). Yes, they are an abomination of sorts, but they heighten the 'blue sky' effect of what is a spectacular cocktail when done right.