AC NO: 70/7460-1A DATE: 1 Jan 72
ADVISORY
CIRCULAR
DEPARTMENT OF TRANSPORTATION
FEDERAL AVIATION ADMINISTRATION SUBJECT: OBSTRUCTION MARKING AND LIGHTING
1. obstruction lights. obstruction marking and lighting and establishes the methods, procedures and equipment types for both aviation red and high intensity white PURPOSE. This advisory circular describes the FAA standards on
2. CANCELLATION. This circular cancels and supersedes Advisory Circular No. 70/7460-1 dated February 1968.
EXPLANATION OF REVISIONS. The standards have been amended to include applicable to skeletal type structures. lighting with high intensity white lights for daytime marking in lieu of painting on smokestacks and similar structures; however, this is not HOW TO OBTAIN THIS CIRCULAR. Obtain copies of this Advisory Circular 70/7460-1A, Obstruction Marking and Lighting, free of charge from the D. C. 20590. Department of Transportation, Distribution Unit, IAD 484,3, Washington, Willem M. Flener Air Traffic Service William M. Flener, Director Initiated by: AI-240
1 Jan 72
TABLE OF CONTENTS Page No.
CHAPTER 1. INTRODUCTION 1
1. Purpose
2. Objective
3. Federal Communications Commission Specifications 1 1 CHAPTER 2. GENERAL REQUIREMENTS 3
4. Application
5. Deviations and Modifications 3 3 CHAPTER 3. MARKING 5
6. Purpose
7. Colors
8. Types of Markers
9. Coloring CHAPTER 4. LIGHTING 11
10. Purpose
12. Qualities of Lighting 14. Special Conditions 11. Location of Lighting 13. Operation of Obstruction Lighting 18 11 11 12 14 CHAPTER 5. OBSTRUCTION MARKING AND LIGHTING EQUIPMENT 21
15. Paint
16. Lights and Associated Equipment 21 21 CHAPTER 6. SEAN AVIA TOR RED ORNE STANDARDS FOR LIGHTING OBSTRUCTIONS TO AIR NAVIGATION WITH AVIATION RED OBSTRUCTION LIGHTS 25
17. Purpose
18. Application
19. Specifications 25 26 Page 1
AC 70/7460-1A 1 Jan 72 Page No.
CHAPTER 7. STANDARDS FOR LIGHTING OBSTRUCTIONS TO AIR NAVIGATION WITH HIGH INTENSITY WHITE OBSTRUCTION LIGHTS 39
20. Purpose
21. Application 39
22. Specifications 39 40 CHAPTER 8. STANDARDS FOR DUAL LIGHTING SYSTEMS ON OBSTRUCTIONS TO AIR NAVIGATION 44
24. Application 23. Purpose 44 44
25. Specifications 44 APPENDIX I. EXAMPLES FOR MARKING AND LIGHTING OBSTRUCTIONS (19 Pages) Page il
1 Jan 72 AC 70/7460-1A CHAPTER 1. INTRODUCTION
1. PURPOSE. This advisory circular describes the FAA standards on obstruction marking and lighting and establishes the methods, procedures and equipment types as official Federal Aviation Administration policy.
OBJECTIVE. The Administrator of the FAA has the statutory responsibility for promoting safety in air commerce. In the light of this responsibility the FAA describes the standards in this publication as the most effective means of indicating the presence of obstructions to pilots.
FEDERAL COMMUNICATIONS COMMISSTON SPECIFICATIONS. The specifications for obstruction marking and lighting antenna structures, contained in Subpart C of Part 17 of the Federal Communications Commission Rules and Regulations, are identical with the standards outlined in this publication for marking obstructions with bands of aviation surface orange and white color in accordance with Chapter 3 and for lighting obstructions in accordance with Chapter 6.
Chap. l Par. 1 Page 1 (and 2)
1 Jan 72 AC 70/7460-1A CHAPTER 2. GENERAL REQUIREMENTS
4. APPLICATION.
a. Objects to be Marked and Lighted. When any object or portion thereof, either temporary or permanent, exceeds any standard for determining obstructions set forth in Part 77 of the Federal Aviation Regulations (14 CFR 77) and/or a height of 200 feet above site level that object should be marked and lighted in accordance with the applicable standards described herein, unless an FAA aeronautical study determines that the absence of such marking and/or lighting will not impair safety to air navigation,
b. Recommended Equipment. Recommended types of equipment and the guidelines for marking and lighting of obstructions are contained in circular. the standards, specifications, and procedures outlined in this
5. DEVIATIONS AND MODIFICATIONS. After initially determining, through application of the two basic criteria, that an object should be marked and lighted, a further determination may be made on whether the application of the marking and lighting can be modified, or a deviation from the standards be concurred in, The final determination that may result in an agency recommendation for a modified application of the marking and lighting, or a deviation from the standards must be based on an FAA finding that the recommended marking and lighting would be effective to the extent that an acceptable level of safety is achieved.
Deviations. Deviations from the obstruction marking and lighting standards set forth in this publication should have the coordinated deviations are changes in:
(1) Basic signals and intensity.
(2) Flashing rates.
(3) Dimensions of described color bands or rectangles.
(4) Colors prescribed, etc.
Chap. 2 Par. 4 Page 3
AC 70/7460-1A 1 Jan 72
b. are: protection for air commerce. Some examples of modified applications his designee, conducting the study, marking and lighting in Modifications. Modified applications of the standards may be accordance with the proposed modification would provide adequate recommended when, in the opinion of the FAA regional director or
(2) The object may be located with reference to other objects or The object may be so removed from the general flow of air marking would serve no useful purpose. traffic or so conspicuous by its shape, size, or color that lighting standards need be applied to only a portion of it. the contour of the ground so that the specific marking and/or
(3) The object may present such a potential hazard that marking of greater height or size. or lighting should be provided similar to that for an object
(4) Other similar situations.
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1 Jan 72 AC 70/7460-1A CHAPTER 3. MARKING PURPOSE. The purpose of marking a structure which may be an obstruction to air commerce is to warn airmen during the hours of daylight of its presence. To accomplish this objective, it may be necessary to color such an obstruction so that it will be visible from aircraft at any normal angle of approach, or to indicate its general definition and location by use of suitable markers or flags.
COLORS. Maximum visibility of an obstruction by contrast in colors can best be obtained by the use of aviation surface orange and white.
TYPES OF MARKERS. Markers of various types should be used to mark obstructions when it has been determined that it is impracticable to mark such obstructions by painting, or it has been determined that markers should be used to provide protection for air commerce in and white colors. addition to that provided by the application of aviation surface orange
a. Display. Markers should be displayed on or adjacent to the obstructions in conspicuous positions so as to retain the general definition of the obstruction and should be recognizable in clear which an aircraft is likely to approach the obstruction.
b. Shapes. Markers should be distinctively shaped so that they are not mistaken for markers employed to convey other information, and they should be such that the hazard presented by the obstruction they mark is not increased.
Spherical Markers. Markers displayed on overhead wires should be spherical in shape with a diameter of not less than 20 inches. They may be of another shape, provided the projection of such type of marker on any vertical surface, normal to each direction from which an aircraft is likely to approach the obstruction, will not be less than that presented by the spherical type marker described above, marker should be displayed for each 150 feet, or fraction At least one such thereof, of the overall length of the overhead line. These markers should be placed at equal intervals not more than 150 feet apart with the top of each marker not below the level of the highest wire at the point marked, and should be colored as specified by paragraph 9, COLORING. The distance between markers on overhead wires located more than 15,000 feet from the reference point of the nearest landing area may be increased to a distance of not more than 600 feet.
Chap. 3 Par. 6 Page 5
AC 70/7460-1A 1 Jan 72 Flag Markers. Flags may be used to mark obstructions when it has been determined that marking such obstructions by coloring or by spherical markers is technically impracticable.
(a) of the obstruction or around its highest edge and should Display. The flags should be displayed around or on top mark. When flags are used to mark extensive obstructions not increase the hazard presented by the obstruction they displayed at approximately 50-foot intervals. or groups of closely spaced obstructions, they should be
(b) Shapes. The flags should be rectangular in shape and have or nearby surfaces. they will support the flags free of the ground, vegetation, The flag stakes should be of such strength and height that stiffeners to keep them from drooping in calm or light wind.
(c) Color Patterns, Flags should be in one of the following patterns:
Solid color aviation surface orange not less than two feet on a side.
Iwo triangular sections, one of aviation surface orange and the other of aviation surface white, combined to form a rectangle not less than two feet on a side.
A checkerboard pattern of aviation surface orange and minus 10 percent on a side, combined to form a rectangle not less than three feet on a side. aviation surface white squares, each one foot plus or
9. standard in paragraph 15,a. been developed for use by government agencies and private industry for marking obstructions to air navigation. Orange or white enamel or and luminance factors satisfy the specifications of the Federal COLORING. Paints and enamels of aviation surface orange and white have reflective paint may be used for marking provided its chromaticity Page 6 Chap. 3 Par. 8
1 Jan 72 AC 70/7460-1A * a. General. The specifications of surface colors apply only to freshly colored surfaces. Colors used for surface markings usually change deviates from the limits of the FAA Aviation Surface Orange Color Tolerance Chart. *
(1) Deletion of Painting. If the smooth surface of the 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.
However, the omission of paint should be restricted to actual surfaces the painting of which will endanger maintenance personnel, and care should be taken that the overall marking effect of the painting is not reduced,
(2) Areas Where Applied. On skeletal-type structures paint should be applied to all surfaces of all parts (both inner and outer) of the framework.
b. Variations.
(1) Solid. An obstruction, the projection of which on any vertical plane has both dimensions less than five feet, should be colored aviation surface orange.
(2) Bands. Towers, poles, smokestacks and similar obstructions, as well as buildings of certain shapes and dimensions, having essentially unbroken surfaces, the projection of which on any vertical plane is five feet or more in one dimension, and is less than 15 feet in the other dimension, and any skeletal or smokestack-type obstruction having both dimensions five feet or more, should be colored to show alternate bands of aviation surface orange and white. The bands should be perpendicular to the major axis of the obstruction, with the band at each end colored aviation surface orange. The widths of the bands should be equal and the width of each band should be approximately one-seventh of the length of the major axis of the obstruction, provided that each band shall have a width of not more than 100 feet nor less than one and one-half feet.
If the structure under study is a smokestack, skeletal structure, flagpole or similar object erected on top of a building, the combined height of the object and the supporting building should be considered the overall height to determine whether obstruction marking should be applied;
however, only the length of the major axis of the smokestack, skeletal structure, or flagpole in this situation would determine the width of the color bands.
Chap. 3 Par. 9 Page 7
AC 70/7460-1A 1 Jan 72 is located with reference to other objects or the contour of the ground so that marking need be applied to only a portion of it, the width of the applied bands should be determined by the length of the major axis of the complete structure and not of just the colored portion, Minimum Number of Bands. If a recommendation is made that the colored bands should be applied to only the upper portion of a structure, at least three colored bands, of a width determined by applying the "one-seventh rule" to orange pattern as a minimum color display. the length of the major axis of the structure, should be displayed on that upper portion to ensure an orange-white- * (d) Deletion. If flashing white high intensity obstruction lights are installed on a smokestack for day marking, no aviation surface orange and white stripes would be required.*
(3) Checkerboard Pattern. Water towers, grain elevators, gas holders, and similar obstructions, as well as buildings of certain shapes and dimensions, having essentially unbroken surfaces the projection of which on any vertical plane is 15 feet or more in both dimensions, should have their top and vertical surfaces colored to show a checkerboard pattern of alternate rectangles of aviation surface orange and white.
it is technically impracticable to color the roof of a building to show alternate rectangles of aviation surface orange and white, such roof may be colored aviation surface orange, The sides of the rectangles should measure not less than five feet nor more than 20 feet. The rectangles at the corners of surfaces should be colored aviation surface orange.
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AC 70/7460-1A 1 Jan 72
(3) Spherical Shaped Structures. obstructions such as water towers and gas holders of spherical If a part, or all, of certain shape does not permit the exact application of the checkerboard pattern of coloring, then the shape of the alternate rectangles of aviation surface orange and white covering the spherical shape may be modified to fit the particular shape of the structural surface, provided the dimensions of these modified rectangles remain to the extent practicable within the dimensioncheckerboard pattern. al limits set forth in the specifications for coloring by the Limited Pattern. If certain obstructions such as gas holders and grain elevators are of such large size that the application of the checkerboard pattern of coloring to the complete outer surface of the structure would be impracticable, the application of the checkerboard pattern of coloring may be limited to the upper one-third of the structure, provided the aeronautical study indicates that the modified marking will provide adequate pro- tection for air navigation.
d. Special.
(1) Marking of Vehicles. Vehicles customarily used on landing areas should be marked in accordance with the provisions of Advisory Circular No. 150/5210-5, Painting, Marking and Lighting of Vehicles Used on an Airport.
* (2) Buildings or Similar Obstructions. When the upper portion of a building or similar extensive obstruction projects above an airport imaginary surface, as described in Part 77 of the Federal Aviation Regulations, the point or edge of it highest in relation to the airport imaginary surface should be regarded as the itop of the obstruction." In certain cases, however, such as when the airport imaginary surface concerned is an approach or transition surface, i.e., sloping, this point or edge highest in relation to the airport referenced surface may not be the highest point or edge above a horizontal plane passing through the base upper parts of which are higher above a horizontal plane passing In such cases, those portions of the object, the through the base of the object than the upper part considered as the "top of the obstruction," should also be obstruction marked. *
(3) Hazard Areas. The FAA will recommend appropriate marking in an area where towers, poles, and similar obstructions are so grouped as to present a common hazard to air commerce; where the hazard of a particular obstruction is increased by guy wires or flight may exist. other appurtenances; or, where an invisible hazard to aircraft in Page 10 Chap. 3 Par. 9