Endurance Flights Click on the following links to learn more about endurance flights during the interwar years. Round-the-Rim Flight Transcontinental Reliability and Endurance Test First Alaskan Flight Doolittle's Atlantic-to-Pacific Flight First Air-to-Air Refueling Endurance Flights Propellers First Transcontinental Nonstop Flight Maughan's Dawn-to-Dusk Flight Flight of the Question Mark Click here to return to the Early Years Gallery.