Does anyone know if you can get this with the UAV? Or does it have to be one of the 'proper' choppers? 
 
Cheers.

propper choppa only as far as i know

Get into the Blackhawk in that Autumn sniping map on Rush. Make sure nobody's in it.
 
Circle around to the first Russian tiny island (provided the consoles aren't blown up yet). Quickly fly close to the ground and start sitting on people around the back, near the small hill with the MG. Repeat as necessary or until your chopper blows up. The middle section between the 2 consoles is fine too.

Yes you can get it with the UAV....that's how I got it.

I tried numerous times with the UAV, but it doesn't seem to kill them, only bumps into them, even going at full speed.

Just got it with the USB. On Nelson Bay. When during a Hardcore Rush battle. Second B objective. A group of 3 tried to disarm the bomb. Got the UAV through the door. Killed all of them :D
 

Just got this today with the blackhawk, saw a guy running out in the open and smoosh

I got one with a blackhawk too when I tried to land to repair the thing. I did not see a sniper camping there where I landed. Oh well, I got me the BLEEP-BLOOP.

haha, awesome

got this today :) with the UAV it's easier i think, you can sneak round the back and ram into a sniper

When I tried with the UAV, I just seemed to but them but do no damage.
 
I actually got this achievment by mistake. I hit a tree, which sent the helicopter flying and somewhere in the tussle I killed a guy.

Cheers for all your replies! UAV it is then - I'm retarded at flying proper helicopters, I just embarrass myself!  
 
I'm gonna get straight on this - when my Xbox comes back from Frankfurt. :( Grr.