a_GniiiniGeiineee 001893: dose was continuing to rise at the rate of 50 mr./min,. and the radiological advisor aboard decided to disontinue the mission and return to base. The standby aircraft took off and was flown to a point on a bearing of 330 degrees at a distance of 120 miles from surface zero. AH / 8 hours the aircraft searched on course 225 degrees, but no fallout was encountered. At H / 10 hours the active fallout area was reentered at bearing 283 degrees, 140 miles from surface zero, and a sample taken. At H / 13 hours a third sample was collected at bearing 278 degrees, 150 miles from surface zero. This was a smaller sample, perhaps 1012 fissions, compared to 19/9 for the first two. 2.3.4 Oak Event. | There was no rocket participation during Shot Oak. Circumstances leading to the discontinuation of the rocket sampling portion of the project are outlined in Section 2.3.5 and Appendix A. 5 samples were taken from the cloud by B-57D aircraft between 2 and 26 hours post shot time (see Tables B5 & B6). Both the wing tank and coincident samplers were operative on all flights. A WB-50 aircraft collected samples from the northeastern edge of the fallout pattern at 4, 6, 8, 10 and 11-1/2 hours after the detonation. The fallout was encountered on a bearing of 300-310 degrees at 65, 93, 125, 160 and 187 miles from surface zero, SAN GION The operation progressed without incident, due mainly to the experience gained by the participating personnel 59