ake MAPLE EVENT OPERATION HARDTACK 1, The MAPLE device was detonated south of Fox Island, Bikini Atoll, at 0530M, 11 June 1958. The cloud rose immediately to 40,000 feet, and it was tracked by radar from the USS Benner, the top at 52,000 feet, By 1420 minutes, aircraft reported Radar cloud information was excellent, end by +30 minutes a definite shear was noticed. The upper portion of the cloud, from 15,200 feet to 47,000 feat, moved east and spread south. The smaller, lower portion of the cloud had definite westerly movement: 2, A P2V aireraft (Wildroot 10) reported over Nan at H+30 mirutes, and it was vectored from Nan to How to Choe to Uncle to William to How. Only background was recorded. Tracks from How to Bravo and from How due west were made. At the extreme west, a field of 1,500 mr/hr was ercountered, which gave the sampler an estimated 100 mr/hr continuous background reading. Since the upper cloud movament to the east constitued a possible hazard to Nan, another P2V aircreft (Wildrcot 15) was scrambled at O710M. P2V was placed in an orbit east of Nan by 10 miles, The first Fallout from the gast never did materialize, and re-entry hour was declared at 0945M. The area A west of the lagoon was placed uncer radex control and surveyed by the seo nd P°V until 1200M. 3. Helicopter surveys were initiated at 0700M by TU-6 at Nan, Negative readings were obtained along the southern chain, but readings of from 28 r to 480 r were recorded on the islands adjacent to ground zero. TAB A 153