One of the most sensational avation event was the Air Service round-the-world flight in 1924. Four Douglas World Cruiser airplanes departed Seattle, Washington, on April 6, 1924, heading westward for Asia via Alaska, piloted by Major Frederick Martin,Lieutenant Lowell H. Smith, 1st Lieutenant Leigh P. Wade and Lieutenant Erik Nelson. The airplanes were specially equipped with wheel landing gear that could be changed depending on the location, and were also especially equipped with pontoons. In preparation for the flight, the United States Navy delivered thirty spare engines to various places around the world. The Navy, with the help of Royal Air Force, delivered thousands of gallons of fuel to various places around the world, before the flight commenced.

The planes encountered the worst type of flying weather — excessive head winds, rain, ice, snow and fog. The fourth airplane, the Seattle, crashed into a mountain on April 30 while flying through fog, near Port Moller, Alaska.  Crew was declared lost, however, Martin and Sgt. A.L. Harvey, were uninjured and walked to safety after 10 days. By May 9, three airplanes had reached Attu Island in the Aleutians, Alaska. They continued on, changing back and forth from pontoons to wheels as determined by whether they were to be flying over land or water. The planes traveled to Japan, before arriving in Southeast Asia, India, England before finally arriving in Ireland. By Aug. 3, they were heading for Iceland from the British Isles when the Liberty engine in the Boston lost all oil pressure, and the plane was forced to land at sea. Unfortunately, high waves damaged the Boston excessively and it had to be sunk.

The New Orleans and the Chicago continued westward, arriving in Nova Scotia  and where the original prototype DWC, named the Boston II, joined them for the remainder of the flight. The three planes reached Seattle on Sept. 28, 1924, completing an aerial trip of approximately 26,000 miles in 6 months and 371 hours flying time. For their tremendous achievement in flying around the world, the World Flyers were awarded the coveted Mackay Trophy for 1924.

Reference:

http://www.historyorb.com/day/april/6

http://www.nationalmuseum.af.mil/factsheets/factsheet.asp?id=751

http://www.firstflightcentennial.org/the-first-flight-around-the-world/