# Chagter 4 ~ Test Aircraft part ofthe mission charged to Task Group 7.) was to provide, maintain and operate aircraft in support of diagnostic and weapons effects test missions, These aircraft supported a large number of scientific pro-~ jects gathering scientific data. the Test Aircraft Unit. Most of these aircraft were operated by Some of the aircraft in this classification were operated by the Test Services Unit. These were aircraft supporting tech- nical and documentary photography projects. Figure 3 aircraft participation in nuclear test events. shows the complete This chart shows all air- craft airborne at H-Hour, both test support and test aircraft, as well as those test aircraft which were airborne after H-Hour, Test aircraft par- ticipation may be divided roughly into four () categories: - Samplers, effects aircraft, instrument carriers and photographic aircraft. The mission of the Sampling Element was to collect particulate and gaseous samples from within the nuclear cloud. The nucleus of this organ- ization was the 926th Test Squadron (Sampling), a subordinate unit. of the LoSOth Test Group (Nuclear). The 926th operated ten (10) B-57B aircraft, especially modified to perform its primary mission of collecting samples from nuclear clouds. For Operation HARDTACK, the Sampling Element was augmented by six (6) specially modified B-57D aircraft of the 080th Strategic Reconnaissance Wing (SAC), Aircraft of the Sampling Element participated in all of the nuclear tests in the Eniwetok Proving Ground, Only the TEAK and ORANGE shots at Johnston Island did not require the participation of the sampler aircraft. On a typical sampling mission the sample controller aircraft with a scientific observer took off prior to H-Hour. This aircraft was considered a part of the test array and was placed in a safe position, AFWL/HO 7 The distange NOT RETFAganre ma