When the camera focouses up on the "blimp" it's clear that it's solid metal, like a long shiney gas cylinder, and not a balloon. This "blimp" is too skinny to hold enough helium to lift off the ground (most blimps are "fat" in appearance), especially considering the fact that it's whole body is made of metal, which would make it too heavy even for a blimp with much greater volume.

Also it seems to move very quickly compared to a normal blimp. It also displays acrobatics that no normal blimp could perform.

This aircraft makes strange humming and beeping like noises. It's hard to say if the beeping is comming from the ground or the aircraft. People that have seen Ufos often report hearing a humming noise from the craft.