It On 3 March 1952, the Air Proving Ground Command sent two T-33 and crews to Kirtland Air Force Base for training and modification. A week later an additional airplane and crew arrived from Eglin Air Force Base, and an airplane and crew from Wright Air Development Center, As these four aircraft were being modified and instrumented for sampling, the crews went ‘to school, conducted by the Lg2sth,”2 When the lectures on sampling were finished, the crews commenced simlated cloud missions, Some 30 flights were made y using vapor clouds in the Albuquerque area, In addition tothe jet aircraft, oe B-29 bomber belonging to the 925th took samples duringTUMBLER/SNAFPER, It was included to conduct an experiment in cabin filtering for sampling aircraft, On former missions, the aircraft crew depressurized the aircraft and went on 100 per cent oxygen just before the first pass at an atomic cloud, The crew then remained on 100 per cent oxygen until the aircraft landed, During TUMBLER/SNAPPER, the B-29 sampling mission was conducted with the aircraft pressurized and without the 100 per cent oxygen and, from all indications, no crew member breathed contaminated air, Minor leaks in the aircraft resulted in some slight contamination to the clothing and skin of the crew, bot the mission was more comfortable and with less than normal contamination in the interior of the aircraft.°? Control of the samplers underwent a change during TUMBLER/SNAPPER. To avoid the constraints inherent in ground control, for TUMBLER/SNAPPER a sampler control aircraft was employed, This was a B-29 bomber carrying a flight crew, a radiological director, and representatives from both 51 AFWUHO SWEH-2-003h; nO ow