China Clipper flight departure site when Sikorsky S-42 "Samoan Clipper" exploded over Samoa in January, 1938. "Hawaii Clipper" disappeared westbound from Guam to Manila in July, 1938. There were unsubstantiated rumors of Japanese involvement, similar to those arising from the disappearance of Amelia Earhart a year earlier. Earhart's navigator, Fred Noonan, had been navigator aboard "China Clipper" during the initial airmail flight. Boeing 314 flying boats "Honolulu Clipper" (NC18601) and "California Clipper" (NC18602) joined the surviving Martin M-130s in 1939, and "Pacific Clipper" (NC18609) and "Anzac Clipper" (NC18611) extended service to New Zealand and Australia in 1941. "Philippine Clipper" returned to Wake when it received
Fred Noonan one month later, they tried starting again, this time leaving California in the opposite (eastward) direction. Earhart characterized the pace of their 40-day, eastward trip from Burbank to New Guinea as "leisurely". After completing about 22,000 miles (35,000 km) of the journey, they took off from Lae on July 2, 1937, and headed for Howland Island, a tiny sliver of land in the Pacific Ocean, barely 2,000 meters long. Their plan for the 18-hour-long flight was to reach the vicinity of Howland using Noonan's celestial navigation abilities and then find Howland by using radio signals transmitted by the U.S. Coast