"Project Blue Book then issued its own explanation, stating that "Operation Big Blast ... a SAC/NORAD training mission" had been active on the night of the sighting and that it could have accounted for the UFO.Project Blue Book's supervisor, USAF Major Hector Quintanilla, wrote policemen Bertrand and Hunt that "in addition to aircraft from this operation [Big Blast], there were also five B-47 aircraft flying in your area during this period ... since there were many aircraft in the area, at the time, and there were no reports of unidentified objects from personnel engaged in this operation, we might then assume that the objects [you] observed between midnight and two a.m. might be associated with this military air operation."