Martin M-130 China Clipper US Navy transport for Manhattan Project

In early 1930s, Pan Am requested for a flying boat with capability that could fly across the ocean. Martin's bid of Model-130 was successful. In 1934, three M-130 were built as Martin Ocean Transports, but to the public thay were all referred as the China Clipper. On November 1935, the China Clipper flew the first trans-Pacific airmail route. Their range and capacity made them prime candidates to fulfill the over ocean hauling needs of the military during World War II. Beginning in 1942, the two remaining planes were pressed into transport roles for the United States Navy, but not given a Naval designation and was maintained their "civilian" status so that they could continue to fly into neutral ports with secret missions for Allied spies and techicians. The most special mission was to fly shipments out of Africa with the uranium needed for the highly top secret Atomic bomb development, the "Manhattan Project". The Philippine Clipper crashed in San Francisco in 1943, and the final China Clipper broke up and sank in Trinidad Tobago in 1945.