Chopper as in helicopter, not chopper as in shredder-mulcher thing.
The TV program seemed to have been made in New Zealand (we weren't close enough to the TV to hear the sound, we weren't at home at the time) and the crop was grown in a field of corn. It didn't seem to be a patrolling helicopter, it was definitely a raid; the helicopter was used to ferry the police persons in and out of the area, and the harvested crop out.
I hope they were all strapped securely into the helicopter, or else they might have floated away.