0018933 Fallout R-values for sr70 and csl37 collected in different locations from Tewa and Zuni showed variations of up to an order of magnitude. The fallout collections from those stations closest to the zero point were most depleted in these nuclides. Flathead and Navajo gave much less change in the R-values with distance from the zero point; at most a factor of two. 3-4 EFFECTIVENESS OF INSTRUMENTATION The aircraft-borne sampling equipment performed in a generally satisfactory manner throughout the entire operation with the exception of some malfunctioning of the gas compressor pumps on the first shot. This was due primarily to the shortage of time for checkout prior to actual operational use.- As the participating personnel gained experience, communications improved and the sampling flights progressed more smoothly. Each of the three types of aircraft sampling equipment is considered to be well suited for its intended use. Difficulties experienced with the rocket samplers are fully described in Chapter II and Appendix A.