2+ SPECIAL CLOUD TRACKING (WILSON) FLIGETs: , a. The first of these flights, Wilson 2, wes directed by Rad Safe to pre-planned post-shot seerch. This requireé tre aircraft to remain in a holding pettern treck approxicately 50 miles West of Ground Zero from plus two to plus five hours. This portion of the track was designed for the purpose of dee tecting radioactive cloud movements toward Friwetok atoll. of BRAVO the meximum activity encountered wes less then 15 cr/hr. Through a misunderstanding of control procedures, Wilson 2 ovesstayed in the holding pattern. When Rad Safe realized this fect, CIC wes requested to order him into the previously designated search sector at once. The delay, however, resulted in this aire craft being well behind and to the North of the cloud sescects thet must nave caused fallout on Rongerik and Rongelap. gt. 155%: the aircraft reported its maxirur reading during this fligtt. Tris wes reported es being between 500 and 1000 mr/br approximately 150 nautical miles from Ground Zero at a bearing of 60 desrees. This and the subsequent deta appeared to verify the forecast cloud trejectories which incicated the upper cloud segments would leave ths PPG on an approximate bearing of 70 degrees, thus avoiding the populated atolls. Wilson 2 sudsequently reported ic-flight difficulty with the instruments used. be On thes besis of the results of the Wilson 2 flight the second tracker, Wilson 3, wes instructed to searct the sass general area but to proceed further Fast to define the rate of cloud movement. gt approximetely 2000M% information was received indicating the possibility of some contamination in the Ronge> Rongeleap area. A message was immediately dispatched to T¢ Fi requesting Wilson 3 to alter his search area in such a manne> as to cover tne populated erea to the East. Communication delays prevented Wilson 3 from complying with the request. This plus the fact that no exact instrument readings (instead a range of readings) were reported made interpretation of cloud tracking data difficult. ; Ce Subsequent wilson flights ( for plus one day) were cancelled when it appeared that no eir ccntazminetion protier existed at that tims. / 6. Sc 7 WEATHE RECONNAISSANCE FLIGETS: Two Petrel Juliet jeetber reconnaissence flights were flown on plus one dey. These flights were fica to tae Southang to the Southeast and indicetec essentially zero air coxcta=-cetscse 2 tal