no contamination except for a single contact of 0.001 R/hr, 800 nmi (1,480 km) northeast of ground zero at H+33. Air Force sample collections made from D+4 to D+7 near Hawaii and off the California coast detected very low levels of radiation. The results of the NYKOPO monitoring survey flight over the inhabited atolls are shown in Table 47. AIRCRAFT DECONTAMINATION. Because of a possible early turnaround after the UNION shot, the cowlings of a B-36 control aircraft (No. 1386) were removed 10 minutes after landing and decontamination was started immediately without a decay period. Its initial survey of 0.090 R/hr was comparatively low (see Table 48), justifying the procedural change. All other aircraft were "cooled" for 26 to 44 hours before decontamination was Started. YANKEE. The 26-hour period was used for those aircraft scheduled for As a consequence, some aircraft were released to maintenance with radiation readings as high as 0.400 R/hr. Even after a 44-hour decay pe- riod, some of the other aircraft were released with high readings. WB-29 aircraft No. 7271 presented considerable difficulty with contamination on its nose area where soft putty had been used as a sealer and apparently entrapped some radioactive particulate material. It was released with a reading of 1.700 R/hr, which was quite high but considerably down from its initial intensity of 40.000 R/hr. YANKEE ~ YANKEE, the final CASTLE detonation at Bikini, was fired at 0610 on 5 May 1954. The 13.5-MT device was detonated on a barge anchored south of Iroij at the same location as the UNION shot. CJTF 7 intended to detonate NECTAR at Enewetak prior to YANKEE; however, unfavorable Enewetak winds concurrent with favorable Bikini weather led to a 4 May cancellation of NECTAR and the scheduling of YANKEE. Preshot Preparation An initial informal command briefing was held at 1100 on 4 May on Parry. No significant fallout was predicted outside the danger area, and 296 30f