This is coolbert:
Much to my surprise the observation by combat aviators of Unidentified Flying Objects [UFO] not merely confined to that period of World War Two onward.
During the Great War [WW1] combat pilots also observing and ENGAGING IN COMBAT WITH UFO!
From an UFO Internet web site and copied almost in entirety:
"UFOs in History: 1916 Incident"
"Strange lights were [also] observed by members of the Royal Flying Corps defending London from Zeppelin raids on the night of 31 January 1916, just as many pilots observed similar unexplained aerial phenomena during the Second World War. On the night in question, orders were sent to the fighter aerodromes to the effect that Zeppelins were approaching London. At 7.40pm Lieutenant RS Maxwell arose from Hainault Farm Aerodrome, near Romford in Essex. At 8.25 his engine was '...missing irregularly and it was only by keeping the speed of the machine down to 50mph that I was able to stay at 10,000 feet. It was at this time that I distinctly saw an artificial light to the north of me, and at about the same height. I followed this light northeast for nearly 20 minutes, but it seemed to go slightly higher and just as quickly as myself...and I eventually lost it completely in the clouds.'" (PRO Air 1/611 16/15/288). [PRO = British Public Records Office]
"At 8.45 pm another aeroplane, piloted by Flight Sub-Lieutenant JE Morgan, may have observed the same UFO after arising from an aerodrome at Rochford, some twenty-two miles east of Hainault Farm. Morgan reported (in an official report to the War Office) that at 5,000 feet he had seen, about a hundred feet away from his aircraft, 'a row of what appeared to be lighted windows which looked something like a railway carriage with the blinds drawn.' In the belief that he had chanced upon a Zeppelin, Morgan fired at the object with his Webley Scott pistol, whereupon 'the lights alongside arose rapidly' and disappeared!"
Combat personnel making observations of extraordinary phenomenon of what ever type are: 1. Trained observers making rational reports devoid of hysteria. 2. Not having an agenda.
Foo Fighters of the Second World War were not the first time then combat aviators encountered and even attempted to ENGAGE UFO presumably piloted by aliens.