950 THE HONG KONG GOVERNMENT GAZETTE, DECEMBER 17, 1937.
[Schedule
(2) By day, an airship in the circumstances mentioned in sub- IV,-contd.] paragraph (1) of this paragraph shall display a group of two black balls or shapes, each at least 2 feet in diameter, placed vertically one below the other 12 feet apart, the upper one being 25 feet below the control car, and both being visible, so far as practicable, in all directions.
Where necessary, in order to comply with the foregoing pro- visions of this sub-paragraph, the said group of two black balls or shapes may be duplicated.
11.-(1) An airship when moored to a mooring mast shall display at or near the rear a white light visible, so far as practic- able, in all directions at a distance of at least 3 miles.
(2) An airship, when moored to the ground or the surface of the water by a cable, shall display, forward, the white light specified in sub-paragraph (1) (a) of paragraph 9 of this Schedule and at the rear the white light specified in sub-paragraph (1) (d) of that paragraph, and in addition the airship and its mooring cable shall be lighted or marked in accordance with such of the provisions of paragraph 8 of this Schedule as are applicable in the case of a captive balloon.
(3) An airship while picking up its moorings, although it shall be considered as being under way and not being under control, shall display only the lights required by paragraph 9 of this Schedule to be displayed until it is finally made fast.
Sound Signals.
12. In fog, mist, falling snow or heavy rainstorm, whether by day or night, an aircraft on the water shall make the following sound signals :-
(a) if not anchored or moored, a sound, at intervals of not more than two minutes, consisting of two blasts of about 5 seconds' duration with an interval of about 1 second between them:
(b) if at anchor or moored, the rapid ringing of an efficient bell or gong for about 5 seconds, at intervals of not more than 1 minute.
SECTION 11.
Rules as to ground markings and signalling.
General.
13. The meanings given to the various markings, lights and signals in this Section of this Schedule are reserved to them exclusively.
Ground markings, lights and signals on and in the vicinity of
aerodromes open to public use.
14. At every land aerodrome open to public use the following requirements shall be complied with:--
(1) The boundaries of the landing area shall, by means of suitable markings, be rendered clearly visible both to aircraft in the air and to aircraft manoeuvring on the landing area;
(2) In addition, a marking in the form of a circle may be placed on the landing area;
(3) All obstructions existing on the landing area shall be clearly marked;
(4) In case part of the landing area should become unfit for use, such part shall be delimited by clearly visible markings or flags, and may in addition be indicated by one or more clearly
visible crosses.
15. At every aerodrome open to public use the following require- ments shall be complied with:-
(1) The direction of the wind at the landing area shall be clearly indicated by a landing T, wind sleeve, smoke producing wind indicator or other recognized method.