Alright, weird title, but I've tried the thing and it doesn't work. I've loaded the ATV with a fuckton of balloons, throwed it off the wind turbines (and sat on it of course), stayed 16 seconds in the air and I didn't even get ATV Airtime II. I already have the first one.

In a desperate attempt I put an equal ammount of balloons on each nail and the game fucking crashed when I got to the ground.

Is the achievement bugged or am I doing something wrong? Like, can I not be on Sandbox?