Before Project Blue Book came Project Grudge, an Air Force project its director later admitted was to debunk the UFO phenomenon. One file buried in the Grudge data concerns a cylindrical object photographed above Manhattan in 1950 — by one of New York City’s most prestigious photographers (now featured in the Library of Congress).
The photographer, Irving Underhill, was adamant what was in the photo was an object, that wasn’t there before or after it was shot. The Air Force, though, had other ideas. They believed he misidentified the Moon, and forgot he was taking a time-lapse image.
Source documents in order of mention
December 1950 Grudge file (Underhill correspondence): https://ia801301.us.archive.org/view_archive.php?archive=/8/items/bluebook/1950s.zip&file=1950s%2F1950-03-9614319-N-Y.pdf
Other individual two New Mexico and one Delaware cylinder sighting reports unavailable to link — are uploaded in Discord.