TRIMAN
I've allready been hit in the head with a rotor blade and wouldn't like to take up the opportunity again.
Wearing a helmet wont stop you getting your head hit by rotor blades, but will provide some form of attenuation of the impact! At the same time, wearing a helmet will increase your overall height and increase the likelihood of a blade strike. Your peripheral vision, particularly in the vertical plane, will be restricted so you will be even less aware of where the rotor blades are.
I would suggest that you should make better use of the defensive devices that you already have - your eyes in this case - and stop walking under rotor discs until you have ascertained that it is safe to do so!!
