A pilot has an apparent cardiac arrest while on a trans-Atlantic flight.
The co-pilot, in complete control of the flying, calls for medical assistance from the passengers, but conceals the reason.
Four doctors respond to the request: An Italian, A Frenchman, a German and an American.
When they enter the cockpit and see a blue, unconscious, pulseless pilot, the Italian exclaims, "Oh Dio," the Frenchamn cries out, "Sacre Bleu," and the German spurts, "Ach du lieber."
Meanwhile, the American asks, "Blue Cross?"