Project 11,2 = Sampling - H, F, Plank (P, F, Moore) EQUIPMENT Six aircraft equipped for cloud sampling, WHRwere used on this mission: "A" flight, Tiger Red One (F-8h); "B" flight, Tiger Red Two (F-8)); "C" flight, Tiger White One and Two (2-F8's); "D" flight, Hotshot (B-57); control aircraft, Cassidy (B-57). WEATHER « Cloud cover consisted of 3/8 curmmlus to 8,000 feet with occasional higher tops, 3/8 alto-stratus from 12,000 to 18,000 feet plus high thin cirrus above 35,000 feet. The Southerly winds varied from East through South to West at various sampling altitudes but velocities were quite low, CLOUD DESCRIPTION The shot was fired in a large hole in the above described cloud cover, so that the bomb cloud was not mingled with or obscured by natural clouds, The cloud rose in a uniform cylinder to 16,000 feet with no mshrooming at the top and considerable prompt fallout of entrained water. By 45 minutes after burst the cloud had separated into three portions; a cloud at 5,000 feet moving West by North, a portion at 10,000 feet moving slowly to the North, and a portion at 15,000 feet moving very slowly toward the Northeast and remaining partially over ground zero, The top of the cloud was about half the altitude that would usually be predicted for a shot of this yield and the base at 5,000 feet was only about 4 the altitude that would be expected. SAMPLING MISSION Red One was put through the top portion of the cloud at 14,500 and COPIED /DOE LANL RC — 32 = an