Mount Lemmon Air Force Station, Arizona: Stationary radar target answers encrypted IFF
At 10:46 p.m. on July 18, 1957, Capt. Claiborne F. Bickham and a radar crew at Mount Lemmon Air Force Station, Arizona, tracked a stationary target at 42,000 feet about 82 miles northwest that responded to encrypted IFF Mode 3 signals.
Background
At 10:46 p.m. on July 18, 1957, Capt. Claiborne F. Bickham and a radar crew at Mount Lemmon Air Force Station northeast of Tucson, Arizona, tracked a stationary target. Using an MPS-7 L-band search radar and an MPS-14 S-band height-finder, they placed it at 42,000 feet, about 82 miles to the northwest, south of Chandler. The target responded to encrypted military IFF Mode 3 transponder signals and transmitted encrypted responses that produced a 'normal Mode 3 paint' on the radar scopes. A very slight strobe came from the object that resembled electronic countermeasures jamming. The account follows the entry in George M. Eberhart's chronology UFOs and Intelligence (CUFOS) and the sources cited there; it is not an independent determination by From Beyond Space.