Originally made with a rather sweeter Butterscotch Schnapps than is currently on the market - so you might need to substitute 1 part butterscotch syrup if you can find one, or sugar syrup as a last resort.
Named after the habit of airlines to provide butterscotch in flight, sadly curtailed. Freshly sqeezed lime juice is best. Use lime cordial if your Butternut Schnappes is bitter.
Simply shake and pour into white wine glasses.