GM1 HPT-DSN.F.510 Wind direction indicators

(a)General: If the wind direction indicators serving the aerodrome do not clearly indicate the correct wind information at the heliport, additional wind direction indicators should be installed in order to provide wind information to the pilot during approach and take-off.

(b)Location:

(1)A wind direction indicator should be located so as to indicate the wind conditions over the FATO and TLOF and in such a way as to be free from the effects of airflow disturbances caused by nearby objects or rotor downwash. It should be visible from a helicopter in flight, in a hover or on the movement area.

(2)Where a TLOF and/or FATO are subject to a disturbed airflow, additional wind direction indicators located close to the area should be provided to indicate the surface wind on the area.

(c)Characteristics:

(1)A wind direction indicator should give a clear indication of the direction of the wind and a general indication of the wind speed.

(2)A wind direction indicator for the heliport should be a truncated cone made of lightweight fabric and should have the following minimum dimensions:

(i)Length 2.4 m,

(ii)Diameter (larger end) 0.6 m, and

(iii)Diameter (smaller end) 0.3 m.

(3)The colour of the wind direction indicator should be so selected as to make it clearly visible and understandable from a height of at least 200 m (650 ft) above the heliport, having regard to the background:

(i)where practicable, a single colour, preferably white or orange, should be used;

(ii)where a combination of two colours is required to give adequate conspicuity against changing backgrounds, they should preferably be orange and white, red and white, or black and white, and should be arranged in five alternate bands, the first and last band being the darker colour.

(d)A wind direction indicator at a heliport intended for use at night should be illuminated.