Commonwealth Numbered Regulations

1988 NO. 158 CIVIL AVIATION REGULATIONS - REG 192

192. (1) The distress signal shall be transmitted only when the aircraft is
threatened with grave and immediate danger and requires immediate assistance.

(2) In radio telegraphy, the distress signal shall take the form of SOS ( . .
. - - -. . .), sent 3 times, followed by the group DE, sent once, and the call
sign of the aircraft, sent 3 times.

(3) The signal specified in subregulation (2) may be followed by the automatic
alarm signal which consists of a series of 12 dashes, sent in one minute, the
duration of each dash being 4 seconds, and the duration of the interval
between consecutive dashes being one second.

(4) In radiotelephony, the distress signal shall take the form of the word

"MAYDAY", pronounced 3 times, followed by the words "THIS IS", followed by the
call sign of the aircraft 3 times.

(5) By other means the distress signal shall take one or more of the following
forms:

   (a)  the Morse signal . . . - - - . . . with visual apparatus or with sound
        apparatus;

   (b)  a succession of pyrotechnical lights, fired at short intervals, each
        showing a single red light;

   (c)  the two-flag signal corresponding to the letters NC of the
        International Code of Signals;

   (d)  the distant signal, consisting of a square flag having, either above
        or below, a ball or anything resembling a ball;

   (e)  a parachute flare showing a red light;

   (f)  a gun or other explosive signal fired at intervals of approximately
        one minute.