UFO flap

A UFO flap is a rash of reports of unidentified airborne objects. Flap, originally a military term to describe a "period of panic or chaos", is used by ufologists to describe surges of sightings in one geographical area. Longer surges spanning multiple countries may be called waves. Reported sightings of UFOs, public interest in them, and news coverage are highly variable in frequency. The terms UFO, flap, and wave allow for sightings of various unrelated phenomena in the night sky to be discussed as if they are parts of the same aerial event.