Project Blue Book Case #2577. On May 27, 1953, another unidentified object was observed over San Antonio, Texas — the fifth Blue Book unknown from America's military aviation capital (joining Cases #1236, #2052, #2177, and #2521). San Antonio's five cases across 1952-1953 established it as Blue Book's most prolific repeat-sighting city for a concentrated military area.
The four-base complex of Lackland, Kelly, Randolph, and Brooks continued producing cases despite — or perhaps because of — the extraordinary concentration of aviation expertise in the area. May 1953 was in the post-Robertson Panel period, when the pressure to find conventional explanations was at its peak.
The case was classified "Unknown."