UFC 3-535-01
17 November 2005
7-8.2
Configuration
A helipad should be equipped with at least one wind direction indicator located in a
position in order to indicate the wind conditions over the final approach and take-off
area. The wind indicator must be free from the effects of air flow disturbances caused
by nearby objects or rotor wash. It must be visible from a helicopter in flight, in a hover,
or on the movement area. Where a helipad may be subject to a disturbed air flow,
additional indicators located close to the area may be necessary to indicate surface
winds.
7-8.3
Construction
A wind direction indicator must be constructed in order to give a clear indication of the
wind direction and a general indication of the wind speed. An indicator should be a
truncated cone made of light weight fabric. The approximate minimum dimensions are
2.4 meters (8 feet) long, 0.45 meters (18 inches) diameter (large end), and 0.3 meters
(1 foot) diameter (small end). The color selected must make it clearly visible and
understandable from a height of at least 200 meters (650 feet) above the helipad. When
practical the preferred colors should be white or orange. Where it is necessary to
provide adequate conspicuity against varied backgrounds, combined colors are
permitted such as orange and white, red and white, or black and white.
7.8.4
A wind direction indicator intended for use at night must be illuminated, and have a red
obstruction light mounted on the mast.
7-9
PHOTOMETRIC REQUIREMENTS
7-9.1
Perimeter and Landing Direction Lights
These lights must emit omni-directional aviation yellow light with intensities as follows:
2 to 10 degrees vertical
37 cd min.
67 cd average
10 to 15 degrees vertical
20 cd min.
7-9.1.1
A 25 percent reduction in light output is permitted at structural ribs on in-
pavement lights.
7-9.2
Approach Direction Lights
These lights must emit omni-directional aviation white light with intensities as follows:
2 to 10 degrees vertical
5 cd min.
125 cd average
10 to 15 degrees vertical
40 cd min.
7-9.2.1
A 25 percent reduction in light output is permitted at structural ribs of in-
pavement lights.
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