In 1946, during the very early days of helicopter flight, the following tongue-in-cheek article appeared in Training Memoranda ('Tee Emm') magazine.
Helicopters are now being used in the service – not many at present, but more are coming along – and we think you should know something about them. We don't mean know how to drive them – there are special Training Flights for that – but know how not to get 'copped' by them, when you are in the role of an innocent but curious bystander. For they are not quite such simple things as they look, and when on the ground can be very dangerous to people in the vicinity who are not aware of their funny little ways. So here's some gen about them, which may prevent you helicopping it unawares.
First, note the main rotor, that is the big propeller affair on top. This rotates in a horizontal plane about the vertical axis of the aircraft, but the height of the blade tips above the ground varies depending on the revs, and also of course on the slope of the ground on which the aircraft is standing. The average height is about five to six feet – and that is also, unfortunately, about the height of most men.
You should, therefore, at once get rid of any assumption that because the rotor is above the aircraft it is also above you. There is no future in approaching a helicopter within the radius of the main rotor, when the engine is running, even if the rotor is not in motion. (There's even less future, of course, in doing it when the rotor is in motion.) For though the helicopter rotor may be at rest when the engine is running, it can be set going in a second when the pilot engages the clutch, and the pilot has not got a 360° range of vision.
Next, note the tail rotor, that is the small propeller on the starboard side of the tail. This rotates vertically and is in line with the fore and aft axis of the aircraft. The tips of this, too, are about five feet from the ground, or nicely at chest height; and this also can be at rest when the engine is running, but liable to be started up any minute by the pilot who can't see behind him. Moreover, being smaller it is not so easily seen (but just as easily felt), and, in addition, it is situated in what would normally be a safe area with more conventional aircraft.
To sum up, therefore, treat helicopters with respect, and don't think they can be approached in the same way as a Lancaster or even a Moth – however anxious you may be to get up close and see how the darn thing works.
Tee Emm Vol 5 No. 2 May 1946
Don't get helicopped!
