A signalling lamp shall be provided at a controlled aerodrome in the aerodrome control tower.
A signalling lamp should be capable of producing red, green and white signals, and of: a) being aimed manually at any target as required; b) giving a signal in any one colour followed by a signal in either of the two other colours; and c) transmitting a message in any one of the three colours by Morse Code up to a speed of at least four words per minute.
