Damn right it's real!
Occurred during a dis-similar air combat trg sortie (dogfighting with another type jet if yu want to boil it down to absolute basics) with an A-4 Skyhawk somewhere over Israel. Can't remember what happened to the Skyhawk, think he may (probably?) decided he had had enough excitement for one day and parted company with his jet.
If what I have heard is correct, the f-15 recovered to base with fuel, flames and smoke chuffing out of the right wing. As such, neither crew were aware that they were missing said wing! On landing, and immediately after shutdown, the Nav had a shuffty at the damage and had great difficulty in persuading his pilot that they had landed minus wing.
Boeing, on hearing about this were chuffed to bits - after all, what an advert for a combat ac; if it can survive a mid-air collision and make it home safely, what are it's chances of surviving a combat sortie. Cue Boeing share price through the roof and lots of enquiries about buying F-15.
The crux of it, as discovered by the Boeing engineers, was that the F-15 was so wide thanks to those huge intakes and engines, that if you kept up enough speed the airframe performed like a rocket / missile. You wouldn't have a huge amount of directional control, but go fast enough in a straight line and the thing would still generate enough lift to fly.