On Nov 15, 1995 ZetaTalk stated that Flying Triangles were military, not extraterrestrial. On Nov 29, 1999 Caus reported
that triangular UFOs were first reported in the 1980s, and on Jan 14, 2000 an article about NOSS described another
source of man-made flying triangles.
What Are the Flying Triangles?
NOSS, US Military Uses of Space, Jan 14, 2000
The December 1999 issue of Spaceflight magazine carried two letters from writers looking for explanations of a curious celestial phenomenon: a triangle of lights crossing the night sky.
NOSS/Parcae sightings probably do not account for very many of the flood of "triangle UFO" sightings. The lights are dim, are visible only for an hour or so before and move in straight lines across the sky. Still, the phenomenon underscores the richness of prosaic visual stimuli out there waiting to mislead naive observers, and so would-be researchers should do well to rule NOSS out as an explanation before leaping to conclusions.
Satellites are not just steady points of light - they can flash and can travel "in formation." They can emit clouds of fuel or waste water or even sport visible thread-like tethers. Letter writer Nick Spall described what he saw from Cornwall at about 10 PM on August 10, 1999. The triangular-shaped formation moved from north to south passed the star Altair. "With the naked eye the formation appeared as one object," Spall wrote. However, "through binoculars (7x50) the group was resolved into three steady pinpoints travelling together in formation."
The Hickman Report - Flying Triangle Overview
UFOSEEK - UFO News Today, Nov 30, 1999
Many ufologists have noted in the past few years that we have had a major change in the type of craft we are seeing in the skies overhead. In the past, most "UFO's" were either the classic "flying disk" type, or cylinders, or even just anomalous lights in the skies. Today we have noticed a major increase in sightings that are of a specific type of aerial vehicle, the dark triangle. This type was first thought to have been seen in Belgium in the '80's ...