Old Fashion
I had to look this one up:
Main alcohol: Whisky
Ingredients: 1 1/2 oz Bourbon or Rye whiskey, 2 dashes Angostura bitters, 1 Sugar cube, Few dashes plain water
Preparation: Place sugar cube in old fashioned glass and saturate with bitters, add a dash of plain water. Muddle until dissolved. Fill the glass with ice cubes and add whiskey. Garnish with orange slice, and a cocktail cherry.
Served: On the rocks; poured over ice
Standard garnish: Orange slice, Cocktail cherry
Drinkware: Old Fashioned glass
Assuming Delta stocks "bitters", I don't think it is unreasonable to ask for one on what's marketed as "Business Class". I bet an FA on SQ can handle this.
Nevertheless as a practical matter, I am afraid BSBD is right.