Help! My helicopter's stuck!

Eldest advises me that his school doesn't allow children to throw helicopters up in the air and watch them as they twirl in delicate circles to the ground. There is a very real danger that someone's eye could be taken out by one of nature's lethal weapons.

I have advised eldest that he should continue to enjoy the twirliness of helicopters and, should anyone have their eye taken out by a lethal twirl, I shall personally buy them a new eyeball.