Beginning in June, 1945, the Navy airmen and aerologists flew two kinds of missions. Almost daily they went out to check the weather, and if they found a full-grown typhoon or one in formation in an advanced stage, special reccos were sent out. One flight went out as soon as it was daylight and the second took off about six hours afterward, early enough to make sure that the second would be completed by nightfall. This was rather tough going. As one of the aerologists pointed out, Pacific distances were so large that if they were considered in terms of similar distances in the United States, a common mission would be like a take-off from Memphis and a search of the area of a triangle extending from Washington, D. C., to New York City and back to Memphis. Aircraft used by the Navy were Catalinas (PBY’s), Liberators (PB4Y-1’s), and Privateers (PB4Y-2’s). All were four-engined, land-based bombers, some fitted with extra gasoline tanks for long ranges. Before leaving base in the Philippines or the Marianas, the aerologists briefed the crews. In flight, the aerologist directed changes in the course of the plane, but the pilot could use his own judgment at any time when he thought the change might exceed operational safety. From June through September, 1945, the Navy flew a total of one hundred typhoon missions, averaging ten hours each. Lieutenants Paul A. Humphrey (a Weather Bureau scientist after the war) and Robert C. Fite, both of whom flew constantly on these missions, gathered data from all flight crews, and at the end of the season wrote descriptions of five typhoons which were more or less typical. Some of the most interesting of these missions were directed into the big typhoon which came from the east, crossed Luzon in the Philippines and roared into the China Sea, in the early part of August. On the fourth of the month, one of the Catalinas was checking the weather three hundred miles east of Leyte and saw a low pressure system developing a small tropical disturbance. It grew, was checked daily, and on the sixth blew across Luzon and reached its greatest fury in the South China Sea on the seventh. The first plane that went into the typhoon in this position was directed to the right and north of the center, to take advantage of tail winds and to spiral gradually into the center. As it approached the center, the plane climbed to about five thousand feet, and the crew had a beautiful panoramic view of the clouds piled up on the outer rim of the eye. On account of the awful severity of the turbulence the plane had experienced around the eye, they descended again and flew to home base at altitudes between two hundred and three hundred feet.