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Codes and Standards |
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Chapter 4. Lighting 40. PURPOSE.
41. STANDARDS. The standards outlined in this AC are based on the use of lighting units that meet specified intensities, beam patterns, color, and flash rates as specified in AC 150/5345-43. These standards may be obtained from:
Note-. All flashing lights on a stmctttre should flash simultaaeously except for catenary support stxu~s which have a distinct sequence fh~b~.g betweea levels. 42. SYSTEM CONFIGURATIONS. Obstruction lighting may be displayed on structures as follows: a. Aviation Red Obstruction L/gMs. Use flashing beacons and/or steady burning lights during nighttime. b. Medium Intensity Flashing White Obstruction Lights. Medium intensity flashing white obstruction lights may be used during daytime and twilight with automatically selected reduced intensity for nightthne operation. When this system is used on structures 500 feet (153m) AGL or less in height, other methods of marking and lighting the structure may be omitted. Aviation orange and white paint is always required for daytime marking on structures exceeding 500 feet (153m) AGL. This system is not normally recommended on structures less than 200 feet (61m) AGL. c. High Intensity Flashing White Obstruction Lights. Use high intensity flashing white obstruction lights during daytime with automatically selected reduced intensities for twilight and nighttime operations. When this system is used, other methods of marking and lighting the structure may be omitted. This system should not be recommended on structures 500 feet (153m) AGL or less, unless an FAA aeronautical study shows otherwise. d. Dual Lighting. This system consists of red lights for nighttime and high or medium intensity flashing white lights for daytime and twilight. When a dual lighting system incorporates medium flashing intensity lights on structures 500 feet or less, or high intensity flashing white lights on structures of any height, other methods of marking the structure may be omitted. e. Obstruction Lights During Construction. As the height of the structure exceeds each level at which pennanent obstruction lights would be recommended, two or more lights of the type specified in the determination should be installed at that level. Temporary high or medium intensity flashing white lights, as recommended in the determination, should be operated 24 hours a day until all permanent lights are in operation. In either case, two or more lights should be installed on the uppermost pan of the structure any time it exceeds the height of the temporary construction equipment. They may be mined off for periods when they would interfere with construction personnel. If practical, permanent obstruction lights should be installed and operated at each level as construction progresses. The lights should be positioned to ensure that a pilot has an unobstructed view of at least one light at each level. f. Temporary Construction Equipment Lighting. Since there is such a variance in construction cranes, derricks, oil and other drilling rigs, each case should be considered individually. Lights should be installed according to the standards given in CHAPTER 5. , CHAPTER 6., CHAPTER 7., or CHAPTER 8. as they would apply to permanent structures. (See CHAFFER 3. for daytime marking.) 43. CATENARY LIGHTING. Lighted markers should be used for increased night conspicuity of high-voltage (69KV or higher) transmission line catenary wires. These markers should be used on transmission line catenary wires near aixpons, heliports, across rivers, canyons, lakes, etc. The lighted markers should be manufacturer certified as recognizable from a minimum distance of 4,000 feet (1219m) under nighttime, minimum VFR conditions or having a minimum intensity of at least 32.5 candela. The lighting unit should emit a steady burning red light. They should be used on the highest energized line. If the markers are installed on a line other than the highest catenary, then spherical markers specified in paragraph 34 should be used in addition to the lighted markers. (The maximum distance between the line energizing the lighted markers and the highest catenary above the lighted marker should be more than 20 feet.) Markers should be distinctively shaped, i.e., spherical, cylindrical, so they are not mistaken for items that are used to convey other information. They should be visible in all directions from which aircraft are likely to approach. a. Size and Colon The diameter of the markers used on extensive catenary wires across canyons, lakes, rivers, etc., should be not less than 36 inches (91cra). Smaller 20-inch (51cra) markers are permitted on less extensive power lines or on power lines below 50 feet (15m) above the pound and within 1,500 feet (458m) of an airport runway end. Each marker should be a solid color such as aviation orange, white, or yellow. (See paragraph 131 for color standards.) b. Installations. 1. Spacing. Lighted markers should be spaced equally along the wire at intervals of approximately 200 feet (6lin) or fraction thereof. Intervals between markers should be less in critical areas near runway ends (i.e., 30 to 50 feet). If lighted markers are installed on a line other than the highest catenary, then spherical markers specified in paragraph 34 should be used in addition to the lighted markers. The maximum distance between the line energizing the lighted markers and the highest catenary above the lighted markers should be no more than 20 feet. The lighted markers may be installed alternately along each wire if the distance between adjacent markers meets the spacing standard. This method allows the weight and wind loading factors to be distributed. 2. Pattern. An alternating color scheme provides the most conspicuity against all backgrounds. Mark overhead wires by alternating solid colored markers of aviation orange, white, and yellow. Normally, an orange marker is placed at each end of a line and the spacing is adjusted (not to exceed 200 feet) to accommodate the rest of the markers. When less than four markers are used, they should all be aviation orange. 44. RATED LAMP VOLTAGE. To ensure the proper lumen output, for fixtures with incandescent lamps, the voltage provided to the lamp filament should not vary more than plus or minus 3 percent of the rated voltage of the lamp. The input voltage should be measured at the lamp socket with the lamp operating during the hours of normal operation. Lamps should be replaced after being operated for not more than 75 percent of their rated life or immediately upon failure. Flashmbes in a light unit should be replaced immediately upon failure, when the peak effective nighttime intensity falls below 2,000 effective candela, or when the fixture begins skipping flashes, or at the manufacturer's recommended intervals. (See paragraph 23, for reporting requirements in case of failure.) 45. NONSTANDARD LIGHTS. Moored balloons, chimneys, church steeples, and similar obstructions may be floodlighted by fixed search light projectors installed at three or more equidistant points around the base of each obstruction. The searchlight 6. Wind Turbine Rotor Blades. Each rotor blade should be marked, front and back, with three bands of orange and white paint beginning with an orange band at each tip. The bands should be approximately the same width as those on the tower. The remaining (inner) blade area may be any color. ( See APPENDIX 1., FIG 10.) d. Teardrop Pattern. Spherical water storage tanks with a single circular standpipe support may be marked in a teardrop striped pattern. ( See APPENDIX 1., FIG 4.) The tank should show alternate stripes of aviation orange and white. The stripes should extend from the top center of the tank to its supporting standpipe. The width of the stripes should be equal, and the width of each stripe at the greatest girth of the tank should not be less than 5 feet (1.5m) nor more than 15 feet (4.6m). e. Community Names. If it is desirable to paint the name of the community on the side of a tank, the stripe pattern may be broken to serve this purpose. This open area should have a maximum height of 3 feet (0.9m). ( See APPENDIX 1., FIG 4.) 34. MAFIK£R$. Markers are used to highlight structures when it is impractical to make them conspicuous by painting. Markers may also be used in addition to aviation orange and white paint when additional conspicuity is necessary for aviation safety. They should be displayed in conspicuous positions on or adjacent to the structures so as to retain the general definition of the structure. They should be recognizable in clear air from a distance of at least 4,000 feet (1219m) and in all directions from which aircraft are likely to approach. Markers should be distinctively shaped, i.e. spherical, cylindrical, so they are not miataken for items that are used to convey other information. They should be replaced when faded or otherwise deteriorated. a. $pkerical Markers. Spherical markers are used to identify overhead wires. Markers may be of another shape, i.e., cylindrical, provided the projected area of such markers will not be less than that presented by a spherical marker.
(a) The diameter of the markers used on extensive catenary wires across canyons, lakes, rivers, etc., should be not less than 36 inches (91cra). Smaller 20-inch (51cra) spheres are permitted on less extensive power lines or on power lines below 50 feet (15m) above the ground and within 1,500 feet (458m) of an airport runway end. Each marker should be a solid color such as aviation orange, white, or yellow. (See paragraph 131 for color standards.)
(a) Spacing. Markers should be spaced equally along the wire at intervals of approximately 200 feet (6lin) or fraction thereof. Intervals between markers should be less in critical areas near runway ends (i.e., 30 to 50 feet). They regardless of its position or color. The monitor (aural or visual) should be located in an area generally occupied by responsible personnel. In some cases, this may require a remote monitor in an attended location. All obstruction lights should be visually inspected on a regular basis. 48. ICE SHIELDS. Where icing is likely to occur, metal grates or similar protective ice shields should be installed directly over each light unit to prevent falling ice or accumulations from damaging the light units. 49. DISTRACTION. a. Where obslruction lights may distract operators of vessels m the proximity of a navigable waterway, the sponsor must coordinate with the Commandant, U.S. Coast Guard, to avoid interference with marine navigation. b. The address for marine information and coordination is: Chief, Short Range Aids to Navigation Division (G--NSR) U.S. Coast Guard Headquarters 2100 2nd Street, SW, Washingtou, DC 20593-0001
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