On This Day in History / May 25, 2023 1927: Lt James H. Doolittle performed the first known successful outside loop. Flying a Curtiss P-1B Hawk pursuit, he began the maneuver in level flight at 10,000 feet (3,048 meters), then pushed the nose down into a dive. When he reached 280 miles per hour (450 kilometers per hour), Doolittle continued to pitch the nose “down” and the airplane flew through a complete vertical circle, with the pilot’s head to the outside of the loop.