a - — side loading effects on the B-52, particularly on the fin, The aircraft arrived in the Eniwetok Proving Ground late in March and became operational early in April. The B-52 flew a total of 176 hours during its participation in HARDTACK, It flew in fourteen nuclear detonations and in twenty practice missions for these events, The events in which the B-52 flew were: FIR, KOA, YELLOWWOOD, TOBACCO, SYCAMORE, ROSE, MAPLE, WALNUT, REDWOOD, ELDER, OAK, CEDAR, DOGWOOD and POPLAR. The Air Force Effects Element had not intended to participate in so many events, This larger participation was made nécessary because several of the earlier shots failed to produce the expected yield. On the shots which failed to come up to expectations, this element did not get sufficient usable data and had to be programmed for a larger number of shots. See Figure g for a summary of the B-52 flying activities on HARDTACK. With the POPLAR Event, the Air Force Effects Element completed its participation in Operation HARDTACK. parted Eniwetok, On 16 July the B-52 and its crew de- It is noteworthy that during Operation HARDTACK, the B-52 had no air aborts and no pre-take off cancellations. In addition, on 28 June, it participated in the REDWOOD Event at Bikini with H-Hour at 0530 and in the ELDER Event at Eniwetok with an H-Hour of 0630; only one (1) hour later. This is the first time that an effects aircraft has par- ticipated in two (2) events in one (1) day and within one (1) hour of each other. The B52 then participated in OAK the following day, estab- lishing the remarkable record of participation in three (3) major nuclear test events in twenty-six hours. The instrument carrying aircraft have been so styled to differentiate APWUHO O\ G