6 AOERRR | Entirely too much time was used to decontaminate aircraft and excessive exposures were being accumulated by aircraft maintenance personnel who participated in decontamination. Maintenance crews in the 4930th Test Support Group (Test Support Unit) did not assist with aircraft decontamination after the BRAVO shot. For subsequent shots, although personnel from the TSuU were still involved, nonmaintenance personnel were used. These men were assigned to decontami- nation teams of 15 men each that operated on 6-hour shifts. TG 7.4, which was primarily responsible for aircraft operations, was most involved in this. Holmes & Narver constructed the Enewetak decontamination pad used for the CASTLE aircraft. This pad drained toward a 24-inch (6l-cm) central catch basin that drained into the lagoon through an 8-inch (20-cm) pipe. The general procedure for decontamination operations was: 1. On D-day sampler F-84G, WB-29, and FB~36 aircraft 2. All other aircraft were checked on landing for evidence of radiological contamination. If an aircraft was contaminated above 0.025 R/hr, it was isolated and posted. 3. Sampler FB-36 aircraft were parked on the decontami- 4. Unless urgency was a factor, no decontamination was undertaken until D+l. Sampler aircraft were given decontamination priority over those accidentally contaminated. 5. Decontaminated aircraft were released to maintenance personnel before release to flying crews. 6. Before aircraft were cleared for flying again, the radiation intensity at crew positions had to be less than 0.010 R/hr. were parked in the designated hot decay area. nation pad and checked for radiation intensities. Following sequential operations for decontaminating various aircraft, radiation intensity measurements sometimes increased rather than decreased. Three primary causes were proposed (Reference 30): 1. Wash water (containing a concentrated amount of contaminants) collected in engine cowlings 157