1.3 Clipper era
Pan Am started its South American routes with Sikorsky S-38 and S-40 flying boats. The S-40, larger than the eight-passenger S-38, had begun flying for Pan Am in 1931. Carrying the nicknames American Clipper, Southern Clipper, and Caribbean Clipper, they were the first of the series of 28 Clippers that symbolized Pan Am between 1931 and 1946.
In 1937 Pan Am turned to Britain and France to begin seaplane service between the United States and Europe. Pan Am reached an agreement with both countries to offer service from Norfolk, Virginia, to Europe via Bermuda and the Azores using the S-40s. A joint service from Port Washington, New York to Bermuda began in June 1937, with Pan Am using Sikorskys and Imperial Airways using the C class flying boat RMA Cavalier.
On July 5, 1937 survey flights across the North Atlantic began. Pan Am Clipper III, a Sikorsky S-42, landed at Botwood in the Bay of Exploits in Newfoundland from Port Washington, via Shediac, New Brunswick. The next day Pan Am Clipper III left Botwood for Foynes in Ireland. The same day, a Short Empire C-Class flying boat, the Caledonia, left Foynes for Botwood, and landed July 6, 1937, reaching Montreal on July 8 and New York on July 9.
Trippe decided to start a service from San Francisco to Honolulu and on to Hong Kong and Auckland following steamship routes. After negotiating traffic rights in 1934 to land at Pearl Harbor, Midway Island, Wake Island, Guam, and Subic Bay (Manila), Pan Am shipped $500,000 worth of aeronautical equipment westward in March 1935 using the North Haven, a 15,000 ton merchant ship it chartered for the purpose of provisioning each island that the clippers would stop at on their 4 to 5-day flight. Pan Am ran its first survey flight to Honolulu in April 1935 with a Sikorsky S-42 flying boat. The airline won the contract for a San Francisco – Canton mail route later that year and operated its first commercial flight carrying mail and express (no passengers) in a Martin M-130 from Alameda to Manila amid media fanfare on November 22, 1935. The five-leg, 8,000-mile (12,875 km) flight arrived in Manila on November 29 and returned to San Francisco on December 6, cutting the time between the two cities via the fastest scheduled steamship by over two weeks. (Both the United States and Philippine Islands issued special stamps for the two flights.) The first passenger flight left Alameda on October 21, 1936. The fare from San Francisco to Manila or Hong Kong in 1937 was $950 one way (about $15580 in 2014) and $1,710 round trip.
On August 6, 1937 Juan Trippe accepted United States aviation's highest annual prize, the Collier Trophy, on behalf of PAA from President Franklin D. Roosevelt for the company's "establishment of the transpacific airline and the successful execution of extended overwater navigation and the regular operations thereof." Later, Pan Am used Boeing 314 flying boats for the Pacific route: in China, passengers could connect to domestic flights on the Pan Am-operated China National Aviation Corporation (CNAC) network, co-owned with the Chinese government. Pan Am flew to Singapore for the first time in 1941, starting a semi-monthly service which reduced San Francisco–Singapore travel times from 25 days to six days. The Boeing 314s were used on transatlantic routes starting in 1939.
Six large, long-range Boeing 314 flying boats were delivered to Pan Am in early 1939, and the new type enabled the start of scheduled weekly contract Foreign Air Mail (F.A.M. 18) service and later passenger flights from New York (Port Washington, L.I.) to both France and Britain. The Southern route to France was inaugurated for Air Mail on May 20, 1939 by the Yankee Clipper piloted by Arthur E. LaPorte flying via Horta, Azores and Lisbon, Portugal to Marseilles. Passenger service over the route was added on June 28, 1939 by the Dixie Clipper piloted by R.O.D. Sullivan. The Eastbound trip departed every Wednesday at Noon and arrived at Marseilles on Friday at 3 pm GCT with return service leaving Marseilles on Sunday at 8 am and arriving at Port Washington on Tuesday at 7 am. The Northern transatlantic route to Britain was inaugurated for Air Mail service on June 24, 1939 by the Yankee Clipper piloted by Harold Gray flying via Shediac (New Brunswick), Botwood (Newfoundland), and Foynes (Ireland) to Southampton. Passenger service was added on the Northern route on July 8, 1939 by the Yankee Clipper. Eastbound flights left on Saturday at 7:30 am and arrived at Southampton on Sunday at 1 pm GCT. Westbound service departed Southampton on Wednesday at Noon and arrived at Port Washington on Thursday at 3 pm. After the outbreak of World War II in Europe on September 1, 1939 the terminus became Foynes until the service ceased for the winter on October 5 while transatlantic service to Lisbon via the Azores continued into 1941. During the war Pan Am flew over 90 million miles (145 million kilometers) worldwide in support of military operations.
In 1940 Pan Am and TWA began using the Boeing 307 Stratoliner, the first pressurized airliner in service and the first with a flight engineer in the crew. The Boeing 307's airline service was short-lived, as all were commandeered for military service at the outbreak of World War II.
The "Clippers" — the name hearkened back to the 19th century clipper ships – were the only American passenger aircraft of the time capable of intercontinental travel. To compete with ocean liners, the airline offered first-class seats on such flights, and the style of flight crews became more formal. Instead of being leather-jacketed, silk-scarved airmail pilots, the crews of the "Clippers" wore naval-style uniforms and adopted a set procession when boarding the aircraft.
In 1942, while waiting at Foynes, County Limerick, Ireland for a Pan Am Clipper flight to New York, passengers were served a drink today known as Irish coffee by Chef Joe Sheridan.
During World War II most of the Clippers were pressed into military service. Pan Am pioneered a new air route across Western and Central Africa to Iran, and in early 1942 the airline became the first to operate a route circumnavigating the globe. Another first occurred in January 1943, when Franklin D. Roosevelt became the first U.S. president to fly abroad, in the Dixie Clipper. During this period Star Trek creator Gene Roddenberry was a Clipper pilot; he was aboard the Clipper Eclipse when it crashed in Syria on June 19, 1947.