856
THE HONG KONG GOVERNMENT GAZETTE, NOVEMBER 12, 1937.
(ii) In default of such method of illumination as aforesaid, one of the two following alternative methods of illumination shall be used:-
First method:
There shall be laid out on the ground a line of lights, spaced 50 yards apart, consisting of a central section of six white lights, to indicate that landings should be made on the adjacent portion of the landing area and on either side of the said line, and at least two green lights at one end of the said line and at least two red lights at the other end of the said line, to indicate that landings should be made from the direction of the said green lights towards the said red lights;
Second method :·
There shall be laid out on the ground lights in the form of a T, the shaft of which shall be composed of at least four lights in a line at least 250 yards in length. The light at the foot of the T shall indicate the place where a flying machine or glider should first make contact with the ground and the cross arm of the T shall indicate the place where it should finish its run. Landings may be made on either side of the shaft of the T but always parallel thereto, provided that, in the event of the area situate on either side of the shaft of the T becoming obstructed, the light indicating the cross arm of the T on that side shall be removed and landing shall be effected on the opposite side of the shaft of the T.
If either of the two alternative methods of illumination referred to above is used, the landing T shall not be displayed.
(e) As to approach lighting:-
The most favourable sectors of approach to the landing area may be indicated by green lights.
(f) As to boundary lighting:—
The boundary of the landing area shall be marked by fixed aviation-yellow lights, normally laid out 100 yards apart:
Provided that:-
(i) when there are obstructions on the boundary of the landing area, the lights serving to mark such obstructions may take the place of boundary lights;
(ii) when local conditions render unavoidable the use of gas boundary lights, such lights may be given an intermittent character;
(iii) when the boundary of the landing area cannot be marked, only the extremities of such landing area between which aircraft may move without danger shall be indicated by fixed aviation-yellow lights.
(3) At every water aerodrome open to public use and used for night flying the requirements specified in sub-paragraph (2) of this paragraph shall be complied with except in cases where compliance therewith is obviously impossible.
Distress, Urgency and Safety Signals,
17.-(1) (a) None of the signals referred to in this paragraph may be transmitted except with the authority of the commander or person responsible for the aircraft from which such signals are trans- mitted.
(b) When such signals are sent by radiotelegraphy or radio- telephony, the group or spoken expression shall be sent three times and followed by the group DE and the call sign, also sent three times, of the aircraft which sends it.
(2) As to distress signals:-
When an aircraft is threatened by grave and imminent danger and requires immediate assistance, the following signals shall be used or displayed, either together or separately, before the sending of a message:—
(a) In radiotelegraphy the signal SOS (-
(b) In radiotelephony the spoken expression (corresponding to the French pronunciation of the "'m'aider'').
).
"MAYDAY”
expression