9/27/78 AC 70/7460-1F in conspicuous positions on or adjacent to the obstructions so as to be used to provide protection for air commerce. They should be displayed MARKERS. Markers should be used to mark obstructions when it has been determined that it is impracticable to mark such obstructions by paint- retain the general definition of the obstruction. and white colors when it has been determined that such markings should ing. Markers may also be used in addition to aviation surface orange nizable in clear air from a distance of at least 1,000 feet (305m) in They should be recoghazard they mark is not increased. used to convey other information. be distinctively shaped so they are not mistaken for markers that are all directions from which an aircraft is likely to approach. They should The shape should be such that the
a. Spherical Markers. by a spherical marker. overhead wires. jected area of such markers will not be less than that presented "Markers may be of another shape, provided the pro- Spherical markers are normally displayed on
(1) Display. At least one such marker should be displayed at equal intervals for each 150 feet (46m), or fraction thereot, of the overall length of the overhead line and not lower than the highest wire. The distance between markers may factors to be distributed. spacing standard. This allows the weight and wind loading long as the distance between adjacent spheres meets the spheres may be installed alternately along each wire as overhead wire on which the spheres can be installed, the be increased to not more than 600 feet. (183m) when the from the nearest landing area. Where there is more than one overhead wires are located more than 15,000 feet (4,575m)
(2) Size and Color. The diameter of the markers should not be less than 20 inches (5lcm) and should be colored aviation orange.
b. Flag Markers. Flags may be used to mark obstructions when it has technically impracticable. been determined that the use of coloring or spherical markers is
(1) Die last Pioner are (15m) apart. Display. Flag markers should be displayed around, on top of obstructions, they should be displayed approximately 50 feet used to mark extensive obstructions or closely grouped the obstruction or around its highest edge. When flags are
(2) be of such strength and height that they will support the flags free of the ground, vegetation or nearby surfaces. to keep them from drooping in calm wind. The flag stakes should Shape. Flags should be rectangular in shape and have stiffeners Chap. 3 Par. 11 Page 9
AC 70/7460-1F 9/27/78
(3) Color Patterns. Flags should be in one of the following patterns:
(a) Solid Color. Aviation surfacé orange not less than two feet (0. 6m) on a side.
(b) Orange and White. Two triangular sections, one of aviation surface orange and the other of aviation surface white, combined to form a rectangle not less than two feet (0.6m) on a side.
Checkerboard. A checkerboard pattern of aviation surface orange and aviation surface white squares, each one foot (0. 3m) plus or minus ten percent on a side, combined to form a rectangle not less than three feet (0. 9m) on a side.
*12. SPECIAL MARKINGS. In addition to the marking recommendations included herein other documents contain appropriate guidelines.
a. Vehicles. Advisory Circular 150/5210-5, Painting, Marking and Lighting of Vehicles Used on an Airport, contains provisions for marking vehicles customarily used on landing areas.
FAA Facilities. Obstruction marking for FAA facilities shall conform to FAA Drawing Number D-5480, referenced in Federal Aviation Agency Standard, FAA-STD-003, Paint Systems for Structures.
C• Unusual Complexities. The FAA may also recommend appropriate marking in an area where obstructions are so grouped as to present a common hazard to air commerce. * Chap. 3 Page 10 Par. 11
9/27/78 AC 70/7460-1F CHAPTER 4. GENERAL APPLICATION OF LIGHTING
13. as described. the git ted tech houd be snored to bode 1y 14- "Obstruction lighting may be displayed on structures in any of the high intensity white lights are considered to be far more effective and following combinations: may be reconnended in lieu of red obstruction lights in some instances. systems and aviation surface orange and white paint are considered meeting the-minimum obstruction marking and lighting standards, the daytime and nighttime conditions., Although red obstruction lighting logical visibility. High intensity white lights may be used for both during periods of limited daytine illuminance and/or reduced meteoro- COLORS. Red obstruction lights may be used during the hours of darkness, Aviation Red Obstruction Lights. Flashing aviation red beacons steady burning aviation red lights during nighttime operation. Aviation orange and white paint should be used for daytine marking. - and
b. High Intensity White Obstruction Lights. Flashing high intensity white lights during daytime with reduced intensity for twilight. and nighttime operation. When this type system is used, the marking white paint may be omitted. of structures with red obstruction lights and aviation orange and flashing high intensity white lights for daytime operation. Aviation orange and white paint may be omitted. Dual Lighting. Steady burning aviation red lights for nighttime operation and A combination of flashing aviation red beacons and * High Intensity Obstruction Lights - Twilight/Nighttime Only. daytime marking. Flashing high intensity white lights for twilight and nighttime operation. Aviation orange and white paint should be used for when determining the placement of obstruction lights on a structure: airmen of the obstruction. The following factors should be considered APPLICATION. Whenever obstruction lights are displayed on any structure, obstruction. Obstruction lighting may be displayed in addition to marking (paint) for daytime operation provided such lights more adequately warn will attract the attention of pilots approaching the obstruction from any normal angle while at any altitude up to 1,500 feet (458m) above the they should be of sufficient intensity and installed in a manner that * a • Heights. All heights referred to herein pertain to the obstruction's height above ground level or water, if so situated.
Chap. 4 Par. 13 Page 11
AC 70/7460-1F 9/27/78
b. Determining, Number of Light Levels.
(1) Red Obstruction Lighting Systems. The overall height of the structure including all appurtenances such as rods, antennas, obstruction lights, etc., is used to determine the number of levels of lights. The top level of lights should be installed on the highest point.
(2) High Intensity Lighting Systems. The overall height of the main structure excluding all appurtenances, is used to determine the number of levels of lights. The top level of lights should be installed on the highest portion of the main structure. In addition, a white omnidirectional beacon should be displayed on the highest portion of any antenna or other appur- Adjacent Structures. The elevation of the tops of the buildings in closely built up areas may be used as the equivalent of the ground level when determining the proper number of lights necessary to adequately mark an obstruction.
d. Shielded Lights. If any light is shielded by an adjacent object, additional lights should be mounted on that obiect to retain the general definition of the obstruction. However, the additional lights may be omitted if they do not contribute to the definition of the obstruction.
Temporary Warning Lights. When an obstruction to air navigation is presented during the construction of a structure, at least two lights should be installed at the uppermost part of the structure.
In addition, as the height of the structure exceeds each level at which permanent obstruction lights will be required, two similar lights should be installed at each such level. Temporary lights should be displayed from sunset to sunrise until all of the permanent lights are in operation. The lights should be positioned so as to ensure unobstructed visibility of at least one light at each level from aircraft at any normal angle of approach. If practical, the permanent obstruction lights may be operated at each level as the structure progresses.
(1) Aviation Red Obstruction Lights. Each steady burning temporary light should consist of at least 32.5 candelas when enclosed in an aviation red obstruction light globe. white strobe lights as specified below may be used as temporary warning lights during construction.
Chap. 4 Page 12 Par. 15
9/27/78 AC 70/7460-1F
(2) High Intensity White Obstruction Lights. The flashes do not have to be simultaneous. If battery- intensity), pulsating at approximately 40 flashes per minute. should consist of at least 1,500 candelas (peak effective Each temporary light regular intervals to preclude failure during a scheduled period of operation. operated, the batteries should be replaced or recharged at floodlighted by fixed search light projectors installed at three of at least 15 footcandles over the top one-third of the obstruction. The searchlight projectors should provide an average illumination possess the color characteristics prescribed in Chapter 9, and flash as required. Chimneys and similar obstructions may be or more equidistant points around the base of each obstruction. elevation than that specified for standard obstruction light assemblies, afford equal or greater dependability of operation, Nonstandard Lights. Obstruction lighting other than those specified herein may be utilized provided such lighting installations offer equal or greater light intensity in all angles of azimuth and
g. Hazard Areas. ing would be in addition to such lighting as may be necessary on any natural or man-made obstruction located within the area. or is proposed should be lighted as prescribed by FAA. This light- An area in which a visible or invisible hazard exists Monitoring of Obstruction Lighting. replacement requirement. being lighted the equivalent of not more than 75 percent of their normal life expectancy. Xenon flash tubes are exempted from this and/or light units should be replaced at regular intervals after signalling device will indicate malfunctioning of all flashing visually inspected at least once every two weeks. All the lamps and that all obstruction lighting mounted on the obstruction are less of their position on the obstruction, and of all top lights; and rotating beacons and/or high intensity white lights, regard- by facility personnel. In some cases, this may require relocating obstruction being excluded from the alarm circuit, provided the to the side or intermediate aviation red obstruction lights on an alarm indicator should be located in an area generally occupied the monitor to a remote control station. The FAA will not object should be designed to register any malfunction of any light on the obstruction regardless of its position. The automatic monitoring lights are functioning properly as required. This alarm indicator should be installed and operated to provide an indication that such visually observed at least once each 24 hours. In the event obstruc- tion lighting is not readily accessible for visual observation, a properly maintained automatic visual or audible alarm indicator Obstruction lighting should be Chap. 4 Par. 15 276-776 0 - 78 - 3 Page 13
9/27/78 AC 70/7460- 1F Manufacturers. description of their equipment are listed in the FAA Advisory The names of qualified manufacturers and a Circular 150/5345-1, Approved Airport Lighting Equipment. See Chapter 9.
n• System Reliability. A high reliability rate is imperative in check on all FAA approved equipment supplied by manufacturers all obstruction lighting systems. In order to maintain a quality listed in paragraph m., above, all repetitive outages or persistent system malfunctions should be reported to:
Airports Engineering Division ATIN: AAP-550 Department of Transportation Federal Aviation Administration Washington, D. C. 800 Independence Avenue, S. W. 20591 Telephone No. (202) 426-3824 The notification should include the type of structure being number of person knowledgeable of the problem encountered. obstruction lighted, sponsor's name and address, and telephone 0 • Lighting Equipment. The standards outlined in this advisory should be used. the Airports Service of the Federal Aviation Administration or nonstandard lights in accordance with paragraph 15.f. above, specified intensities, beam patterns, color and flash rates (if appropriate). Therefore, only equipment having been approved by circular are predicated upon the use of lighting units that meet a notes These of Lighting Systems) Designation. A method of designating the specific lighting system configurations. (See Appendix 2, Figures 1-12). lights to be used, has been expanded to cover the high intensity type of lighting system to be employed on a structure, and previously used to designate the number of levels and type of red obstruction
(1) Type of lighting system.
(b) Type B - High intensity obstruction lighting system Iype A - Red obstruction lighting system
(c) Type C - High intensity obstruction lighting system with an appurtenance extending above the top of the structure
(d) Type D - Dual lighting system
(2) Number of levels. The numerical designator immediately following the letter designator, identifies the number of levels of lights.
Chap. 4 Par. 15 Page 15 (and 16)
9/27/78 AC 70/7460-1F CHAPTER 5. RED OBSTRUCTION LIGHTING STANDARDS
16. STANDARDS FOR LIGHTING OBSTRUCTIONS TO AIR NAVIGATION WITH RED OBSTRUCTION LIGHTS a • Flashing Red Beacon. This 300mm flashing beacon consists of two simultaneously flashing incandescent lamps of at least 620 watts with aviation red color filters. The steady burning intensity should not be less than 2,000 candelas (in red). The flashing mechanism should produce not more than 40 flashes per minute nor less than 12 flashes per minute with a period of darkness equal to approximately one-half the luminous period. If the obstruction is Specification I-6273. located within 15,000 feet (4,575m) of a landing area, the flashing beacons should conform to FAA Specification CAA 446, or Military frequency should be not less than 20 flashes per minute. These
b. Steady Burning Red Obstruction Light. This obstruction light con- sists of one or more steady burning lamps of at least 116 watts tion light globe. The intensity should be not less than 32.5 (when used in multiple circuit), enclosed in an aviation red obstruccandelas. If the flashing mechanism is installed so as to make it L-7830. FAA Specification AC 150/5345-2 (L-810), or Military Specification all lights will be permissible. These lights should conform to necessary for these lights to flash, the simultaneous flashing of
(1) Single Obstruction Light. A single unit may be used when more than one obstruction light is required either vertically or be accomplished within a reasonable time period. horizontally to define an obstruction or where maintenance can
(a) Top Level. A single unit may be used to identify low structures such as airport ILS buildings and long horizontal structures such as perimeter fences and building roof outlines.
(b) Intermediate Level. Single units may be used on skeletal and solid structures when more than one level of lights level. is installed and there are two or more single units per Double Obstruction Light. A double light unit should be installed when used as top light and in areas or locations where the failure of a single unit could cause an obstruction to be totally unlighted from any normal angle of approach.
(a) Top Level. Structures not exceeding 150 feet (46m) AGL, should have one or more double units installed at the highest point. These should burn simultaneously.
Chap. 5 Par. 16 Page 17
AC 70/7460-1F 9/27/78 (Б) side fail. with these units to switch light sources should one reasonable time period. A transfer relay may be used Intermediate Level. Double units should be installed at intermediate levels when a malfunction of a single unit could create an unsafe condition, and in remote areas where maintenance cannot be performed within a C. Rated Lamp Voltage. To ensure the proper lumen output, the normal operation. the lamp socket with the lamp operating during the hours of should not be more than plus or minus 3 percent of the rated voltage of the lamp. operating voltage provided to the recommended obstruction lamp The input voltage should be measured at
d. Operation of Red Lights. Red obstruction lights should be operated if practical, face the north sky. the lights may remain on continuously. The sensing device should, rises to a level of not less than 58 footcandles (624.3 lux), or be turned on during daytime when a prominent unlighted object device should turn off the lights when the north sky illuminance cannot be seen from a distance of three statute miles. The control visibility is restricted. In Alaska, however, the lights should They should also be turned on during daytime when the flight surface to a level of not less than 35 footcandles (376.7 lux). by a satisfactory control device adjusted so the lights will be turned on when the north sky illuminance falls on a vertical e • Availability of Specifications.
(I) See Chapter 9. FAA. FAA Specifications CAA 446 and AC 150/5345-2 (L-810) are available free of charge fron the Department of Transportation.
(2) Forms Center. See Chapter 9.
f. Poles, Towers, and Similar Skeletal Structures. The following standards apply to radio and television towers, supporting struc- tures for overhead transmission lines and similar lacy structures.
(1) Top Mounted Obstruction Light.
(a) Structures Not More Than 150 Feet (46m) AGL. Two or more an aircraft at any normal angle of approach. steady burning lights should be installed in a manner to ensure unobstructed visibility of one or more lights from Page 18 Chap. 5 Par. 16
9/27/78 AC 70/7460-1F
(b) Structures Exceeding 150 Feet (46m). AGL. At least one 300mm flashing beacon should be installed in a manner to normal angle of approach. ensure unobstructed visibility from an aircraft at any
(c) Special Cases• Appurtenances Not Exceeding 20 Feet (6m). If a rod, antenna or other appurtenance of not more than 20 feet (6m) in height is incapable of supporting a beacon and it is determined that this appurtenance does not allow unobstructed viewing of a single 300 mm flashing beacon from any normal angle of approach, there should be installed two such beacons properly positioned on top of at least one beacon. of the main structure to permit unobstructed viewing
2. Appurtenances Exceeding 20 Feet (6m)• If a rod, (6m) in height is incapable of supporting a beacon, a supporting mast with one or more beacons should be antenna or other appurtenance greater than 20 feet height within 20 feet (6m) of the tip of the installed adjacent to the appurtenance and to a at least one beacon. appurtenance so as to permit unobscured viewing of
(2) and height of the structure. These lights should be mounted Mounting Intermediate Levels. The number of levels of lights may be obtained from Appendix 2, Figs. 1-3. The number of lights on each level is determined by the shape from any normal angle of approach. so as to ensure unobstructed viewing of at least one light
(a) Steady Burning Lights.
Structures Not More Than 450 feet (137m) AGL. Two on diagonally or diametrically opposite positions. or more steady burning lights should be installed Structures Exceeding 450 Feet (137m) AGL. Install level. steady burning lights on each outside corner of each
(b) Flashing Beacons.
Structures Not More Than 450 Feet (137m) AGL. These of flashing beacons. structures normally do not require intermediate levels Par. 16 Page 19
AC 70/7460-1F 9/27/78 Structures More Than 450 feet (137n) AGL. A flashing beacon should be installed within the structure proper.
If the structural members impair the viewing of the beacon, then two beacons should be mounted on the outof each level. side of diagonally or diàmetrically opposite positions
g. Chimneys, Flare Stacks and Similar Solid Structures.
(1) Top Mounted Obstruction Lights.
Structures Not More Than 150 Feet (46m) AGL. At least three steady burning obstruction lights should be installed at regular intervals on the horizontal plane at or near the top, in a manner to ensure unobstructed visibility of at approach. least two lights from aircraft at any normal angle of
(b) Structures Exceeding 150 Feet (46m) AGL. 300mm flashing beacons should be installed in a Two or more manner to ensure unobstructed visibility from an aircraft at any normal angle of approach.
(c) Chimneys. Lights may be displayed from five (1.5m) to 10 feet (3m) below the top of chimneys to avoid the obscurant effect of the deposits generally emitted by this type of structure. It is important that these lights be readily accessible to enable cleaning when necessary and to facili- tate lamp replacements.
(2) Mounting Intermediate Levels.
(a) The number of light levels may be obtained from Appendix 2, Figs. 1-3. At least three lights should be installed on each level. These lights should be mounted so as to ensure unobstructed viewing of at least two lights on each level.
(b) Flashing Beacons. The number of beacon levels may be obtained from Appendix 2, Figs. 1-3.
1• Structures Not More Than 450 Feet (137m) AGL. These structures normally do not need intermediate levels of flashing beacons.
2. Structures Exceeding 450 Feet (137m) AGL. Two or more flashing beacons should be installed on each level and installed in a manner to allow unobstructed viewing of at least one beacon.
Page 20 Chap. 5 Par. 16
Prominent Buildings and Similar Extensive Obstructions. If individual objects within a group of obstructions are approximately the same overall height above ground, or water if so situated, and are located not more than 150 feet (46m) apart, the group of obstructions may be considered an extensive obstruction. Prominent buildings and similar extensive obstructions should display steady burning obstruction lights in a manner to indicate the extent of the obstruction as Structures Not More Than 150 Feet (46m) in Either Horizontal Direction. If the structure/extensive obstruction is not more than 150 feet (46m) in either horizontal dimension, at least one steady burning obstruction light should be displayed on the highest point of each end of the major axis of the obstruction.
If this method of lighting is impracticable because of the shape of the obstruction, then two lights may be displayed in the center of the highest point.
Structures More Than 150 Feet (46m) in at Least One Horizontal Direction. If the structure/extensive obstruction is more than 150 feet (46m) in either or both horizontal dimensions, at least one steady burning obstruction light should be displayed for each 150 feet (46m), or fraction thereof, of the overall length of the major axis of the obstruction. At least one of these lights should be displayed on the highest point of each end of the obstruction. Additional lights, as required, should be displayed at approximately equal intervals not to exceed 150 feet (46m) on the highest points or edge between the end lights. If there are two or more edges of the same height on an obstruction located near a landing area, the edge nearest the landing area should be lighted.
(3) Special Warning. Flashing or rotating beacons may be used in lieu of steady burning obstruction lights in the event early or special warning is considered necessary. Such beacons should be displayed on the highest points of an extensive obstruction at intervals not exceeding 3,000 feet (915m). At least three beacons should be displayed on one side of the extensive obstruction to indicate a line of lights.
Group of Obstructions. If individual objects within a group of obstruction are not the same height and are spaced more than 150 feet (46m) apart, the prominent objects within the group should be lighted in accordance with the specifications for individual obstructions of a corresponding height. In addition, at least one rotating beacon should be installed at the top of a prominent center obstruction or on a special tower located near the center of the group of obstructions.
Chap. 5 Par. 16 Page 21
AC 70/7460-1F 9/27/78
(5) Obstructions More Than 150 Feet (46m) AGL. Steady burning obstructions lights should be installed at the top as specified in paragraphs (1) or (2) above. At selected intermediate levels, steady burning lights should be displayed for each 150 feet (46m), or fraction thereof. The position of these lights on the vertical plane should be equidistant between the top lights and the ground level as the shape and type of obstruction will permit. One such light should be displayed at each outside corner on each level with the remaining lights evenly spaced between the corner lights.
í• Alternate Method of Displaying Obstruction Lights. In lieu of installing lights on the obstruction, lights may be placed on poles of slightly greater height than the obstruction and installed on or adjacent to the structure.
Chap. 5 Page 22 Par. 16