Blue Book documents and maps indicate that Werlich located the photo position at the end of the radar event at least partly on the basis of contemporary crew testimony to the effect that the camera was not switched on until the end. McCaslin confirms Werlich's contemporary report. This is also consistent with psychological and operational factors. When the UFO first appeared the B-52 was already heading home at this point, there were no bomb-nav exercises in prospect and all that remained to complete the Instructor pilot's Standards & Evaluation exercise was the approach to Minot. When reports were received from RAPCON of a UFO in the area, McCaslin asked Ritchie to switch the radar into Station Keep mode. It was not uncommon to do this during an approach, but camera operation is not automatic and has to be manually selected. No-one thought of the camera until the pilot suggested it near the end of the event.