The Boeing 314 prototype was launched into the Duwamish River on 31 May 1938 and towed to Elliott Bay. It first flew on 7 June. Test pilot Eddie Allen reported that directional control was inadequate. The single tailfin was replaced by endplate fins but this was still insufficient and a central fin was put back on to make it a triple tail. NC18601 entered Pan Am service as Honolulu Clipper. On 4 November 1945 on a flight from Honolulu to San Francisco it made an emergency landing on the ocean with two engines out. Damaged, it was sunk by naval gunfire. Photo from: Boeing

A new Boeing 314, NC18603, at Pan American's Treasure Island base, wearing fleet number 17. Given the amount of people, the photo seems to have been taken during the Golden Gate International Expo which opened here on 18 February 1939. The aircraft flew to Baltimore five days later to join Pan Am's Alantic Division, and was christened Yankee Clipper by Eleanor Roosevelt in Washington, DC on 3 March. Photo from: San Francisco Public Library

Getting President Roosevelt, seated in his weelchair, to the 1943 Casablanca Conference. Dixie Clipper flew Miami - Port of Spain - Belém - Bathurst where FDR transferred to another plane. This was the first US presidential journey by air. Photo from: National Museum of the US Navy

Christened here by Eleanor Roosevelt. Photo from: Library of Congress

The dawn of heavier-than-air passenger service across the Atlantic, 28 June 1939. Somewhat embarrassingly the flight had taken four days due to fog at the Botwood, Newfoundland stop. The aircraft carried 19 passengers, twelve crew and 60,000 letters but this was not considered a regular flight, which causes some confusion. On 28 June, NC18605 Dixie Clipper departed New York on the first regular passenger flight, via the 'southern route' to Marseille through the Azores. Yankee was back in NY on 2 July and flew the first regular pax service to Southampton on 8-9 July. She had also made the first mail flights, to Marseille in May and to Southampton in June. Photo from: Nationaal Archief (Netherlands)

Overflying Pan Am's new seaplane terminal on Treasure Island. All buildings of the Golden Gate International Exposition were razed down in 1940 to make room for a new land airport, but it became a naval facility instead. This is the second Boeing 314 airframe, the first to fly with triple tailfins. Named California Clipper, it was approaching Auckland in New Zealand on a regular transoceanic flight on 7 December 1941 when news came in of the Japanese attack against Pearl Harbor. Captain Robert Ford was ordered to proceed westward to New York and managed to complete an amazing 50,000 km trip via Australia, Java, Ceylon, Karachi, Bahrain, Sudan, Congo and Brazil. Photo from: SFO Museum

One of Pan American's incomparable Boeing 314s takes off near New York. The name "Atlantic Clipper" has been deleted and replaced by "No. 20". She served on Atlantic routes from delivery in March 1939. To US Navy as 48226 but still operated by Pan Am. Returned to PAA and last known flight to Foynes, Ireland was on 18 August 1945. Scrapped in 1946, none of the twelve 314s built survives. Obtained from PAA 60 years ago.