WW2 and the Foofighters: Not radar angels

A radar angel is a false return on radar, a ghost, caused by clouds, birds, temperature inversions and equipment malfunction. In the early days of explaining those unexplained things people were seeing in the skies this was a favored explanation. It was technical, it was scientific and most often hard to prove or disprove - especially when access to the records, photographic displays or other resources were unavailable due to being in the hands of government or military authority.

The "Foofighters" reported by pilots and crews of WW2 were unexplained at the time of their happening. It was a word-of-mouth event that higher ups only heard about after the fact. Once the foo was out the bottle it was a race to explain them away. Explanations ranged from 1) radio controlled craft acting as target tracers or carrying bombs. The problem the sightings never seemed to endanger the planes or the pilots. 2) St. Elmo's Fire - a form of static electricity known to dance around church steeples, wingtips and ship masts. The problem. these were not seen on wings but in the skies. 3) Combat fatigue from the psych officers. And others. None of which ever stood up to much investigation or adequately explained the scope of the sightings.

For some good information view this page.      

Also, this page.