Kirtland AFB. The position assigned for participation in Shot 9 was determined by the allowable load on the horizontal tail. To permit positioning at a higher blast input, the weight configuration of the aircraft initial downloadon the tail, the minimum safe slant range at shock ar-~ rival, assuming a 34 KT weapon yield, was computed to be 26,500 ft. The flight pattern designed to achieve this slant range is shown in Fig. 2.20. The test aircraft flew an orbit identical to that flown by the drop air craft except that the orbit was displaced upward 3000 ft and forward 4830 ft. The test aircraft maintained the proper orbit by using a form of radar navigation knom as "station keeping." A . ° wn te we a te Te Me * a Pt et ana ot ove gt ar er 4 ‘ ow wore This was accomplished by loading 25,000 lb of bombs in the forward bomb bay to rroduce a forward shift in the center of gravity. Accounting for the - Was adjusted so as to obtain a download on the horizontal tail. LA 2 *. . wt? Fe was essentially the same as that employed for Mike Shot. For Shot 9 of UPSHOT-KNOTHOLE, the B~36 aircraft was besed at = sary to synchronize all maneuvers, time-wise, with the drop aircreft. Figure 2,19 shows diagrammatically the planned flight pattern of the B~36D aircraft for King Shot. Operation of the instrumentation equipment ve ee ete et ate tea eet, ae ’ Me aoe oe ee oe Pr a yield vteing considerably smaller for King Shot, the intended slant range at zero time and shock arrival was reduced to 34,000 ft and 62,500 ft, respectively. King Swot was an air drop and, therefore, it was neces- The "K" system radar was used to maintain the desired slant range between the drop aircraft and the test aircraft, and an altimeter was utilized to keep the aircraft at the correct altitude. The procedure for data recording was approxi-‘ mately that employed for IVY. 2.4.2 B47 Aircraft The different structural configuration and performance character- istics of the 5-47 aircraft allowed it to be positioned closer to the burst point at time zero than was the B-36 aircraft, At burst time and shock arrival on Mike Shot, the B-47 aircraft was to be flying straight and level at an altitude of 35,000 ft and heading directly away from ground zero. If the weapon yield reached the predicted upper limit, the maximum allowable temperature would be induced in the 0.025 in. aluminum skin if the aircraft were at a slant range of 75,600 ft at burst time. Positioning on this basis, the resulting slant range at shock arrival becomes 181,948 ft. The flight pattern set-up to position the aircraft for tne shot is shown in Fig. 2.21. The aircraft left Kwajelein Air Base at 08190 hours on shot day and proceeded to the orbiting area east of Eniwetok Atoll to begin the prescribed flight maneuvers. As with the B~36 aircraft, the flight plan called for orbiting until a specified interval before time zero, then leaving the orbit and executing a 90° tum to the left at the proper time so as to orient the aircraft with the tail toward the explosion prior to burst time. Before the maneuver was com pleted, the radar equipment failed causing the aircraft to be out of + Vow a Oe ae position. The three man crew of the aircraft comprised the pilct, co-pilot, and navigator, thus allowing no instrumentation engineer aco_rd during the Slight. The final instrumentation check and balancing of strain channels, therefore, was completed prior to take-off, A comrrehensive instrumentation check-out was scheduled for the day before the test and