A long-time pilot-friend of ours tells a story about his first check ride for the commercial certificate. Everything was going relatively well until the examiner asked him to perform the eights on pylons maneuver. His response was something along the lines of, Yes sir, thank you, sir, and what altitude would you like, sir? The examiner ended the check ride and told him to come back after talking with his instructor about pivotal altitude. When he did, he learned that the correct pivotal altitude for a given groundspeed allows a banked line of sight from the cockpit directly parallel to the lateral axis of the aircraft to the pylon, a stationary object on the ground. Our friend went on to be one of the first pilots to fly the Airbus A300 in the U.S., for Eastern Airlines.