Boeing Military
Boeing 314 Clipper
First flight June 7, 1938   
Produced 1938–1941

The first 314 flight on the San Francisco-Hong Kong route left Alameda on February 23, 1939 with regular passenger and Foreign Air Mail Route #14 service beginning on March 29. A one-way trip on this route took over six days to complete. Commercial passenger service lasted less than three years, ending when the United States entered World War II in December 1941. Passengers and their baggage were weighed, with each passenger allowed up to 77 pounds (35 kg) free baggage allowance (in the later 314 series) but then charged $3.25 per pound ($7.2/kg) (equivalent to $70 in 2023) for exceeding the limit.

The Boeing 314 Clipper was an American long-range flying boat produced by Boeing from 1938 to 1941. One of the largest aircraft of its time, it had the range to cross the Atlantic and Pacific oceans. For its wing, Boeing re-used the design from the earlier XB-15 bomber prototype. Twelve Clippers were built, nine of which served with Pan Am.

Design and development

Pan American had requested a truly trans-Pacific flying boat with unprecedented range and double the passenger payload of the airline's Martin M-130. Boeing's bid was successful and on July 21, 1936, Pan American signed a contract for six. Boeing engineers adapted the cancelled XB-15's 149 ft (45 m) wing, and replaced the 850 hp (630 kW) Pratt & Whitney Twin Wasp radial engines with the 1,600 hp (1,200 kW) Wright Twin Cyclone. Pan Am ordered six more aircraft with increased engine power and capacity for 77 daytime passengers as the Boeing 314A.