They should cross breed all horses with Dartmoor ponys. You have to practically land on the things before they will look up, glare at you and wander about 3 feet away before going back to eating whatever it is they find so tasty on those blasted heaths. The only way you could frighten one with a helicopter is if it was an Apache and you were firing rockets at them, even then I'd give you good odds they'd ignore you.
I've never seen a creature less interested in helicopters, apart from my wife.
