AC NU: 70/7460-1D DATE: 4/18/75
ADVISORY
CIRCULAR
DEPARTMENT OF TRANSPORTATION
FEDERAL AVIATION ADMINISTRATION SUBJECT: OBSTRUCTION MARKING AND LIGHTING PURPOSE. This circular describes the Federal Aviation Administration's standards for obstruction marking and lighting.
2. CANCELLATION. This cancels and supersedes Advisory Circular Number 70/7460-1C, dated December 11, 1973.
EXPLANATION OF REVISIONS. Number 70/7460-1C, by making editorial changes of a minor nature. It advises that although the painting of structures and use of red This circular updates Advisory Circular obstruction lighting, plus spherical markers in the case of overhead transmission lines, are still acceptable and recommended in some advisable. cases, there are instances where increased conspicuity would be In these cases, high intensity lighting systems will be recommended in lieu of paint and red obstruction lights. Spherical markers may also be eliminated in these cases. It also advises that in order for the standards in this advisory circular to be most should be used. effective, only equipment meeting, or exceeding FAA equipment standards where appropriate, the lux equivalent for footcandle values were included. A lighting configuration designation previously employed for the red obstruction lighting system was reinstated and expanded.
The United States customary units of measurement are gradually being replaced by the metric system. Recognizing this trend, we consider it important to prepare for broader use of the metric system. Therefore, for information purposes, metric units have been included in parenthesis next to the English units throughout the text. The metric values are based upon the International Civil Aviation Organization's standard English/metric equivalents rounded off (30 meters equals 100 feet) and, therefore, do not represent exact conversions of the English values.
The English values should be used in applying the standards contained in this advisory circular. This does not involve any change in standard FAA Form 1320-7 (2-71) SUPERSEDES PREVIOUS EDITION Initiated by: AAT-240
TABLE OF CONTENTS Page No.
CHAPTER 1. INTRODUCTION Purpose 1
2. Objective
3. Federal Communications Commission Specifications CHAPTER 2. Objects to be Marked and Lighted GENERAL RECOMMENDATIONS m mmmm n mnnnn nnno ooo Deviations and Modifications
a. Modifications
b. Deviations CHAPTER 3. MARKING
6. Purpose
7. Omission of Standard Marking
8. Colors
a. Orange Number 12197
b. White Number 17875
9. Painting
a. Materials and Application
b. Surfaces Not Requiring Paint
c. Skeletal Structures
10. Patterns
a. Solid Pattern
b. Alternate Bands of Orange and White Checkerboard Pattern 7 Beachball Pattern 8
11. Markers 8
a. Spherical Markers 8
b. Flag Markers 9
12. Special Markings 9 CHAPTER 4. GENERAL APPLICATION OF LIGHTING 11
13. Purpose
14. Colors
a. Aviation Red Obstruction Lights
b. High Intensity White Obstruction Lights Dual Lighting Page i
AC 70/7460-1D 4/18/75
15. Application Page No.
a. Heights
b. Determining Number of Light Levels 11 Adjacent structures
f. d. Shielded Lights Nonstandard Lights Temporary Warning Lights 12 12 12 Hazard Areas
h. Monitoring of Obstruction Lighting Cleaning 12 13 1• j. Lamp types Interference Notification of Light Failure 13 13 13 Manufacturers 13 * o. Lighting System(s) Designation Lighting Equipment 14 14 14 * CHAPTER 5. RED OBSTRUCTION LIGHTING STANDARDS 15
16. Standards for Lighting Obstructions to Air 15
f. Poles, Towers and Similar Skeletal b. Steady Burning Red Obstruction Light d. Operation of Red Lights e. Availability of Specifications a. Flashing Red Beacon c. Rated Lamp Voltage 15 15 16 15 15 15 Structures
g. Chimneys, Flare Stacks and Similar Solid 17 Structures
h. Prominent Buildings and Similar Extensive 18 Obstructions
1. Alternate Methods of Displaying Obstruction 19 Lights CHAPTER 6. HIGH INTENSITY OBSTRUCTION LIGHTING STANDARDS 21
17. Standards for Lighting Obstructions to Air 21 Navigation with High Intensity White Obstruction Lights
b. Light Specifications d. Installation Guidance e. High Intensity Light Units High Intensity Obstruction Light Flashtube Replacements 21 21 22 22 Relocation or Omission of Light Units 23 24 Chimneys, Flare Stacks and Similar Solid 25 Structures Page ii
Page No.
h. Radio and Television Towers and Similar Skeletal Structures 25
i. Hyperbolic Cooling Towers 25
j. Supporting Structures of Overhead Trans- 26 mission (Catenary) Lines K. Prominent Buildings, Observation Towers 28 and Similar Extensive Obstructions CHAPTER 7. DUAL LIGHTING SYSTEMS 31
18. Dual Lighting Systems 31 CHAPTER 8. MARKING AND LIGHTING OF MOORED BALLOONS 33
AND KITES
19. 20. 21. Marking Application Purpose 33 33 33
a. Display 33
b. Shape 33
c. Color Patterns 33
22. Lighting 33 a . Display 33
b. Light Distribution 33
23. 24. Other Federal or Local Government Regulations Light Control Device 34 34 CHAPTER 9. OBSTRUCTION MARKING AND LIGHTING EQUIPMENT 35
25. 26. Paint Purpose 35 35
a. Colors
b. Availability of Specifications 35 35
27. Lights and Associated Equipment a. Aviation Red Obstruction Lighting System 35 35
b. High Intensity White Obstruction Lighting 36 Systems
c. Approved Manufacturers 36
d. e • Availability Installation and Maintenance 36 Recommended Lamp Equipment 36 37 Page iii
AC 70/7460-1D 4/18/75
ILLUSTRATIONS Page No.
APPENDIX 1o Figure 1. Types of Obstruction Lights 1 Figure 2. Painting and Lighting of Chimneys, Poles, Towers and Similar Obstructions 2 Figure 3. Painting and Lighting of Water Towers, Storage Tanks and Similar Obstructions 3 Figure 4. Painting and Lighting of Water Towers and Similar Obstructions Figure 5. Painting of Single Pedestal Water Tower 5 by Beachball Pattern Figure 6. Examples of Installation of High Intensity Obstruction Lights on Chimneys 6 Figure 7. Same as above 7 Figure 8. Same as'above 8 Figure 9. Hyperbolic Cooling Tower 9 Figure 10. Bridge Lighting 10 APPENDIX 2.
Obstructions with Aviation Red Obstruction Lights - Night Standards for Lighting Towers, Chimeys, Poles and Similar Figure 1. 150 feet (45m) to 900 feet (270m) AGL Figure 2. 900 feet (270m) to 1,500 feet (450m) AGL 2 Figure 3. 1,500 feet (450m) to 2,100 feet (690m) AGL 3 Page 1v
Page No.
Standards for Lighting Chimneys and Similar Solid Obstructions with High Intensity White Obstruction Lights - Day and Night Figure 4. 150 feet (45m) to 900 feet (270m) AGL 4 Figure 5. 900 feet (270m) to 1,500 feet (450m) AGL 5 Figure 6. 1,500 feet (450m) to 2,100 feet (630m) AGL 6 Standards for Lighting Towers and Similar Skeletal Obstructions with High Intensity White Obstruction Lights - Day and Night Figure 7. 150 feet (45m) to 900 feet (270m) AGL 7 Figure 8. 900 feet (270m) to 1,500 feet (450m) AGL 8 Figure 9. 1,500 feet (450m) to 2,100 feet (630m) AGL 9 Standards for Lighting Solid and Skeletal Obstructions with Dual Lighting Systems Figure 10. 150 feet (45m) to 900 feet (270m) AGL 10 Figure 11. 900 feet (270m) to 1,500 feet (450m) AGL 11 Figure 12. 1,500 feet (450m) to 2,100 feet (630m) AGL 12 Page v
4/18/75 AC 70/7460-1D CHAPTER 1. INTRODUCTION
1. PURPOSE. To describe recommended standards for the marking and lighting of obstructions as official FAA policy.
OBJECTIVE. To provide the most effective means of indicating the presence of obstructions to pilots, in accordance with the Administrator's statutory responsibility for promoting safety in air commerce.
3. FEDERAL COMMUNICATIONS COMMISSION SPECIFICATIONS. The specifications for obstruction marking and lighting antenna structures contained in Part 17 of the Federal Communications Commission Rules and Regulations are identical with the standards contained in this publication.
Chap. 1 Par. 1. Page 1 (and 2)
4/18/75 AC 70/7460-1D CHAPTER 2. GENERAL RECOMMENDATIONS OBJECTS TO BE MARKED AND LIGHTED. When any object or portion thereof, either temporary or permanent, exceeds a height of 200 feet (60m) above site level or any standard for determining obstructions set forth in Part 77 of the Federal Aviation Regulations (14 CFR 77), that object should be marked and lighted exactly in accordance with the applicable standards described herein in order to be most conspicuous. An FAA aeronautical study, however, may determine that the absence oi such marking and/or lighting will not impair safety to air navigation.
overall height includes all appurtenances such as lights, rods, antennas, DEVIATIONS AND MODIFICATIONS. After an initial determination is made that an object should be marked and lighted, a further determination may be made on whether the marking and lighting can be modified or a deviation from the standards can be concurred in. The final determination for a modification or deviation must be based on a study showing that an acceptable level of safety is achieved.
Modifications. Modifications may be recommended when, in the opinion of the FAA Regional Director or his designee conducting the study, the proposed modification would provide adequate protection for air commerce. Some examples of modifications are:
(1) Marking and/or lighting only a portion of an object. The object may be located with respect to other objects or terrain so that application of the specific marking or lighting standards need be applied to only a portion of it.
No marking and/or lighting. The object may be so located with respect to other objects or terrain, so removed from the general flow of air traffic, or so conspicuous by its shape, size or color that marking or lighting would serve no useful purpose,
(3) Marking or lighting an object in accordance with the standards for an object of greater height or size. The object may present such a potential hazard that higher standards are recommended to ensure the safety of air navigation.
(4) Other similar situations.
b. Deviations. Deviations may be permitted with the coordinated approval of the Director, Air Traffic Service. Some examples of deviations are changes in:
Chap. 2 Par. 4 Page 3
AC 70/7460~1D:
4/18/75
(1) Basic signals and intensity.
(2) Flashing rates.
(3) Dimensions of color bands or rectangles.
(4) Colors, etc.
Page 4 Chap. 2 Par. 5
4/18/75 AC 70/7460-1D CHAPTER 3. MARKING PURPOSE. The purpose of marking a structure is to warn airmen of its presence during daylight hours. To accomplish this objective, it may be necessary to color the structure or indicate its presence by use of * 1° OMISSION OF STANDARD MARKING. When high intensity lighting systems are employed in accordance with the standards contained herein, the marking of structures with standard aviation surface orange and white paint and red obstruction lights may be omitted. The high intensity lighting systems are considered to be far more effective than the aviation surface orange and white paint and may therefore be recommended in lieu of standard marking. This is particularly true under certain ambient light conditions and position of the sun relative to direction of flight. * COLORS, Maximum visibility of an obstruction by contrast in colors can best be obtained by the use of aviation surface orange and white paint.
Orange or white enamel paint may be used for marking, provided its chromaticity and luminance factors satisfy Federal Standards FED-STD 595, color, as follows:
a. Orange Number 12197 (Aviation Surface Orange).
b. White Number 17875 (Aviation White).
9. PAINTING. The specifications of surface colors apply only to freshly painted surfaces. Paints used for surface markings usually change with time. while it is not feasible to require strict maintenance, surfaces should be repainted whenever the color changes noticeably or its effectiveness is impaired by scaling or chipping.
a. Materials and Application. Quality paint materials should be selected to be compatible with the surfaces to be painted, including previous coatings on the surfaces if any, as well as suitable for the environmental service conditions to which it will be subjected. Surface preparation and paint application should be accomplished in accordance with the manufacturer's recommendations as appropriate for the paint to be used and surface to be coated.
b. Surfaces Not Requiring Paint. If the smooth surface of paint on the ladders, decks and walkways of certain types of steel towers and similar structures presents a potential danger to maintenance personnel, such surfaces need not be painted, Care should be taken so the overall marking effect of the painting is not reduced. Where the painting or the act of painting certain precision or critical surfaces would have an adverse effect on the desired transmission or radiation characteristics of a radio frequency signal, such painting may be omitted.
Chap. 3 Pax. 6 Page 5
AC 70/7460-1D 4/18/75 * C• Skeletal Structures. inner and outer, of the framework in order to be effective. This Paint should be applied to all surfaces, both applies to the supporting structures of overhead transmission lines as well as radio, television and similar skeletal strućtures. *
10. PATTERNS. Patterns of various types are used to mark obstructions to air navigation. Normally, the size and shape of the obstruction will determine the pattern to be used.
a. Solid Pattern. plane of less than 10.5 feet (3.2m) in both dimensions, should be colored aviation surface orange. An obstruction having a projection on any vertical
b. Alternate Bands of Orange and White. structures: surface orange and white are normally displayed on the following Alternate bands of aviation
(1) Radio and television towers and supporting structures of overhead transmission lines (see paragraph 11.a).
(2) Poles.
(3) Smokestacks.
(4) Skeletal framework of storage tanks and similar structures.
(5) Structures which appear narrow from a side view.
(a) Width of Bands. The width of bands for structures of any height should be equal, provided that each band has a width of not more than 100 feet (30m) nor less than one and one-half feet (0.5m). The bands should be perpendicular to the vertical axis of the obstruction with the bands at each end colored orange. The width of each band for structures as high as 700 feet (210n) above ground level (AGL) should be approximately one-seventh of the height of the structure, Higher structures should be painted an additional orange and white band for each additional 200 feet (60m) of height, or fraction thereof, with the width of all bands equal and in proportion to the structure's height above ground level, For example, if a structure is:
Greater Than But Not Exceeding Band Width
10.5 feet (3.2m) 700 feet (210m) 1/7 of height of structure 700 feet (210m) 900 feet (270m) 1/9 of height of structure 900 feet (270m) 1,100 feet (330m) 1/1l of height of structure 1,100 feet (330m) 1,300 feet (390m) 1/13 of height of structure Page 6 Chap. 3 Par. 9
4/18/75 AC 70/7460-1D If the top of the structure has a cover or roof, the top orange band should be continued to cover the entire top of the structure. If the object under study is a flagpole, skeletal structure or similar object erected on top of a building, the combined height of the object and building will determine whether marking is recommended;
however, only the height of the object under study determines the width of the color bands.
(b) Partial Marking. If marking is recommended on only a por Elon of a structure because of shielding by other objects or terrain, the width of the bands should be determined by the overall height of the structure. A minimum of three bands should be displayed on the upper portion of the structure.
C. Checkerboard Pattern. Checkerboard patterns of alternate rectangles of aviation surface orange and white are normally displayed on:
(1) Water, gas and grain storage tanks, excluding skeletal framework.
(2) Buildings.
Structures which appear broad from a side view, such as structures having a horizontal dimension 10.5 feet (3.2m) or greater and this horizontal dimension is equal to or greater than the
(a) Size of Rectangles. The sides of the checkerboard rectangles should measure not less than five feet (1.5m) nor more than 20 feet (6m). However, if it is impracticable because of the size or shape of a structure, the rectangle may have sides less than five feet (1.5m), provided their colore ne post of (1.5m) minimum. When possible, corner surfaces should be dimensions remain as close as practicable to the five-foot If it is technically impracticable to color the roof of a structure in a checkerboard pattern, such roof may be colored orange. If part or all of a spherical shaped structure does not permit the exact application of a checkerboard pattern, then the shape of the new rectangles may be modified to fit the shape of the spherical surface.
Chap. 3 Par. 10 Page 7