[princekolt]

No, I believe what happened is that the "jetpack" was either hovering or flying at low speed, and the airplane flew by it. So the pilots could see it approaching and get a visual on the jetpack before it zipped by the side.

[sandworm101]

So a relatively fixed object that they passed at speed? There is even more room there for size distortion. A doll hanging from a drone? A partially-inflated balloon of some sort? Once one person radios "jetman" then subsequent spotters will tend towards that description too.