The "Aviation" cocktail is an IBA "official" cocktail. It is listed on the IBA website with these ingredients and instructions:
All Day Cocktail
- 4.5 cl Gin
- 1.5 cl Maraschino
- 1.5 cl Fresh lemon juice
Shake and strain into a chilled cocktail glass.
To my surprise this doesn't list Crème de Violette at all: not in the ingredients, and not as e.g. "a dash" in the instructions.
Nearly all recipes I've seen so far though (e.g. How to Drink) do have Violette, and they all call out the Aviation as a "blue as the sky" cocktail because of that creme.
So what's the deal here? Is the IBA website just lacking it (perhaps because it's not a "core" ingredient but just a dash or a barspoon, usually)? Or is the "official" version actually without it?