2D orbiting billboards don't work well in 3D space when applied to TF2 unusual effects. The plane wouldn't know when to flip direction and stay symmetric based on the location it is relative to the head. This gives the impression that the plane or helicopter is flying backwards on some directions when it shouldn't be. That's why having an effect that looks like this is so rare.

Dang cool unusual effect, but it should be on something more space-themed.

Actually, how have we not had a single orbiting plane or helicopter unusual effect?

i am in LOVE with Ronald_D_D

very cool effect i like it