During WW2, one of the really odd things that occurred from Nov '44- April '45 was the sightings and encounters by Allied bombers with German "Foo Fighter" weapons. It happened over France with the 415th NFS to start and spread all over shrinking Reich territory. Contrary to popular myth, they were not angels guiding our bombers, nor UFOs, nor atmospheric ball lightning... but rather 4 different German weapons lumped together. Since they seemed luminous or burning, they were call Feu Fighters (French for Fire Fighters) and this was changed to Foo from the Smokey Stover comic of a bumbling fireman that actually started fires. The weapons were the WNF Feuerball flattened turbojet with a chemical burner ring that caused electrostatic discharge within 300 ft of a bomber's engine, disabling it and all airborne radars. The second were AEG Kugelwaffen, mystery plama balls that also carried a stop-motor weapon inside. A third was just a LW anti-radar balloon with a metallic coating and hanging anti-radar strips called Seifenblasen (Soap Bubbles) derived from the Kriegsmarine Aphrodite program. And the last was a single manned enlarged Feuerball called the Zeppelin Werke Kugelblitz (Ball Lightning) that downed a group of B-24s with a gaseous aerosol cloud that detonated the engines! These weapons were observed by hundreds of airmen and were secretly classified by the US under the title PHOO BOMBS. They were photographed and were in US and Allied newspapers, but the USAAF and RAF denied their existence while keeping classified files on them. They ceased when Germany surrendered, but showed up months later with Japan (German U-boat tech transfer). Those also stopped once Japan quit! Their existence on paper and photographic record is secure, but the USAF has released nothing on their data or how many of them were there. Some estimate production of all 4 weapons at under 300. In the PTO they were encountered by the 20th and 21st BGs. The USAAF said that the airmen were having mass hallucinations!