Drone/Heli/Multicopter
As a fixed wing RC aviator of 10 yrs standing I have had much joy and merriment watching RC heli pilots chase their recalcitrant wobble wokkers around the sky. Believe me any RC helicopter more than 400ft above launch point or 400 yards away from the pilot would be an unstable beastie and Mr Newton's laws being what they are the damn thing would fall out of the sky.
The incident suggests therefore a multirotor GPS capable craft with a decent battery performance. £350 from Maplins
Once again technical innovation has outstripped the legislation