AC NO: 70/7460-1F DATE: September 27, 1978
ADVISORY
TED STATES OF ANGE CIRCULAR
DEPARTMENT OF TRANSPORTATION
FEDERAL AVIATION ADMINISTRATION SUBJECT: OBSTRUCTION MARKING AND LIGHTING
1. PURPOSE. This circular describes the Federal Aviation Administration's standards for obstruction marking and lighting.
CANCELLATION. This cancels and supersedes Advisory Circular Number 70/7460-1E, dated November 1, 1976.
EXPLANATION OF REVISIONS. This circular updates Advisory Circular to provide for the use of high intensity lights for nighttime only. Number 70/7460-1E, by making editorial changes of a minor nature. The paragraphs on special markings, notification of light failures, and steady burning red obstruction lights have been expanded to provide additional guidance. The lighting standards have been amended been included in parenthesis next to the English units throughout system. Therefore, for information purposes, metric units have being replaced by the metric system. Recognizing this trend, we The United States customary units of measurement are gradually consider it important to prepare for broader use of the metric SI units. The English/metric equivalents (1 foot equals .305 neters) involve any change in standard dimensions, tolerances or performance the standards contained in this advisory circular. This does not Law 94-168). Section 403 of Public Law 93-380 encourages the use of are rounded off and, therefore, do not represent exact conversions of of Units (SIs) as stated in the Metric Conversion Act of 1975 (Public the text. The metric values are based upon the International System The English values should be used in applying Acting Director, Air Traffic Service Any Seper Initiated by: AAI-240
9/27/78 AC 70/7460-1F
FOREWORD Marking and Lighting Equipment. The FAA strongly recommends that only those lighting systems and paint materials be used that meet the minimum technical standards established by FAA. Considerable effort and research have been expended in determining the minimum systems or marking and lighting obstructions to air navigation. While brighter or quality of materials that will produce an acceptable level of safety in additional lights may be desirable to identify an obstruction to air navigation, and may, on occasion, be recommended, the FAA has specified the minimum level in these standards in the interest of economy, 15h, 1, and j; 16a, b, c, and d; and 17b, and c.) level of safety, obstruction lighting systems should be installed, operated and maintained as stated in these standards. (See paragraphs ecology and energy conservation. Therefore, to provide an adequate Rationale for Obstruction Light Intensities. 91.105 of Federal Aviation Regulations (FARs), Part 91, General Operating and Flight Rules, prescribes aircraft speed, minimum safe altitudes and basic VFR weather minimums for governing the operation of aircraft Sections 91.70, 91.79 and including helicopters, within the United States.
Speed Restrictions. Basically, aircraft may not be operated at speeds in excess of 250 knots (288 mph/463 km/h) while below 10,000 feet (3,048m) above mean sea level; 1f within an airport traffic area, in excess of 156 knots (180 mph/290 km/h) for aircraft with of 250 knots (288 mph/463 km/h). reciprocating engines, and 200 knots (230 mph/370 km/h) for turbine powered aircraft; and within a terminal control area (ICA) in excess Altitude Restrictions. No person may operate an aircraft over congested areas below an altitude of 1,000 feet (305m) above the highest obstacle within a horizontal radius of 2,000 feet (610m) of the aircraft; or, except over open water or sparsely populated areas, below 500 feet (153m) above the surface over other areas;
and not closer than 500 feet (153m) to any person, vessel, vehicle or structure. Also, in operating aircraft at the minimum safe areas, at distances up to 2,000 feet (610m), and when over other altitudes in conformity with Section 91.79, pilots must be able to see and estimate distances from obstructions, when over congested than congested areas, at distances of 500 feet (153m).
visibility minimums in Section 91.105 within controlled airspace with a flight visibility of at least 3 statute miles (4.8 km) and Visibility Minimums. Aircraft may also operate in compliance with flight visibility. outside controlled airspace with a minimum of 1 statute mile (1.6 km) Page 1
AC 70/7460-1F 9/27/78 d• Helicopters. Helicopters may operate at lower altitudes provided the operations are conducted without hazard to persons or property on the surface and also comply with specified helicopters designated routes. Helicopters may also be operated outside of controlled airspace at or below 1,200 feet (366m) above the surface with visibility less than 1 mile (1.6 km) provided it is operated at a speed that allows the pilot adequate opportunity to see-and-avoid e • Guyed Structures• The guys of a 2,000-foot (610m) skeletal tower (there are 10 in existence at or above 2,000 feet (610m)) are anchored from 1,600 (488m) to 2,000 feet (610m) from the base of the structure.
This places a portion of the guys 1,500 feet (458m) from the tower at Structures, including guys, have to be avoided by 500 feet (153m) in a height of between 125 (38m) to 500 feet (153m) above ground level. enacetore, the horizontally. open areas; therefore, the tower has to be cleared by 2,000 feet (610m) Minimum Operating Conditions. A "worst case" situation, 1.e., the minimum condition(s) under which an aircraft can legally be operated and which requires the greatest intensity for an obstruction light to be effective, 18 at any altitude above the surface; in 1 mile (1.6 km) fl1ght visibility; at a maximum speed of 250 knots (288 mph/463 km/h), and remain at least 2,000 feet (610m) horizontally from structures.
Intensity Requirments. An aircraft travelling at 250 knots (288 mph/ 463 km/h) requires 1.48 statute miles to avoid an object by 2,000 feet (610m) once the pilot sees the obstruction light, recognizes the light as marking an obstruction, initiates evasive action, and allowing for aircraft lag. An aircraft travelling at 165 knots (190 nph/306 km/h) requires 1.18 statute miles (1.9 km) to evade an obstruction by 2,000 feet (610m) horizontally. FAA approved obstruction lights meet or exceed the following intensity requirements:
PERIOD TYPE LIGHT COLOR INTENSITY (CANDELAS) Night: Flashing Beacon (300mm) High Intensity Red White 2,000 4,000 (+25%) Steady Burning Red 32.5 Day: High Intensity (Tall Structures) White 200,000 High Intensity White 100,000 (Catenary) Iwil1ght: High Intensity white 20,000 (+25%) Page ii
9/27/78 AC 70/7460-1F Distance Versus Intensities. mile meteorological visibilities: the various intensities can be seen under one (1.6 km) and three (4.8 km) The following table depicts the distance
PERIOD TIME MILES (KILOMETERS) METEOROLOGICAL VISIBILITY STATUTE MILES (KILOMETERS) DISTANCE INTENSITY CANDELAS OBSTRUCTION LIGHT N G 1(1.6) 1,18(1.9) 1,2(1.9) ,64(1) 2,000 3,000 32 Steady Burning-Red Strobe-White 300mm Beacon-Red H T 3(4.8) 3.2(5.2) 3.0(4.8) 2,000 3,000 Strobe-White 300mm Beacon-Red
1.48(2.4) 32 Steady Burning-Red D 1(1.6) {.5(2.4) 200, 000 Strobe-White
1.35(2.2) 100,000 Strobe-White 3(4.8) 3.0(4.8) 200,000 Strobe-White
2.6(4.2) 100,000 Strobe-White TWI- УНОІН 1(1.6) 1.2 (1.9) to 1.5(2.4)* 20,000 Strobe-White 3(4.8) 1.5 (2.4) to 4.0 (6.4) * 20,000 Strobe-White * Distance depends on north sky illuminance:
at 1.5 statute miles (2.4 km). This intensity, under 3 miles (4.8 km) meteorological visibility at night, could generate a residential annoyance is 1 mile (1.6 km). of operation, provided the pilot is operating in accordance with FAR, Part 91. Aircraft operating between 165 knots (190 mph/306 km/h) and to operate under instrument flight rules (IFR) at night when the visibility 250 knots (288 mph/463 km/h) should be able to see the obstruction lighting during which time period 20,000 candelas would be required to see the lights CONCLUSION. Aircraft travelling at 165 knots (190 mph/306 km/h) or less unless the weather deteriorates to 1 mile (1.6 km) visibility at night structure by at least 2,000 feet (610m) horizontally under all conditions should be able to see obstruction lighting in sufficient time to avoid the In addition, aircraft in these speed ranges can normally be expected rage iii
AC 70/7460-1F 9/27/78 DEFINITIONS• ¿ • Flight Visibility. The average forward horizontal distance, from the cockpit of an aircraft in flight, at which prominent unlighted objects may be seen and identified by day and prominent lighted objects may be seen and identified by night. (Airman's Information Manual, Pilot/Controller Glossary).
b. Meteorological Visibility. A term that denotes the greatest distance, expressed in miles, that selected objects (visibility markers) or lights of moderate intensity (25 candelas) can be seen and identified under specified conditions of observation (IES Lighting Handbook, Page 1-21, Fifth Edition 1972).
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TABLE OF CONTENTS Page No.
FOREWORD 1 CHAPTER 1. INTRODUCTION
1. Purpose
2. Objective
3. Federal Communications Commission Specifications CHAPTER 2. GENERAL RECOMMENDATIONS 3 4• Objects to be Marked and Lighted 5 • Deviations and Modifications a • Modifications
b. Deviations CHAPTER 3. MARKING 5
6. rurpose
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 C• Checkerboard Pattern d• Teardrop Pattern
11. Markers
a. Spherical Markers 9
b. Flag Markers 9 9 * 12. Special Markings a. Vehicles 10
b. FAA Facilities 10
c. Unusual Complexes 10 * 10 CHAPTER 4. GENERAL APPLICATION OF LIGHTING 11
13. Purpose 11 Page v
AC 70/7460-1F 9/27/78
14. Colors 11
a. Aviation Red Obstruction Lights 11
b. High Intensity White Obstruction Lights
c. Dual Lighting
d. High Intensity Obstruction Lights - Iwil1ght/Nighttime Only *
15. Application 11 a • Heights
b. Determining Number of Light Levels
c. Adjacent Structures 12 Shielded Lights 12 e • Temporary Warning Lights 12 £ • Nonstandard Lights 13 8• Hazard Areas 13 h • Monitoring of Obstruction Lighting 13
1. Cleaning 14 * k . Lamp Types Notification of Light Failure 14 14 *
1. Interference 14 ™ • Manufacturers 15
n. Systen Reliability 15 Lighting Equipment 15
p. Lighting System(6) Designation 15 CHAPTER 5. RED OBSTRUCTION LIGHTING STANDARDS 17
16. Standards for Lighting Obstructions to Air 17 Navigation with Red Obstruction Lights
a. Flashing Red Beacon 17 * b. Steady Burning Red Obstruction Light 17 *
c. Rated Lamp Voltage
d. Operation of Red Lights
e. Availability of Specifications 18
f. Poles, Towers and Similar Skeletal 18 Structures 8 • Chinneys, Flare Stacks and Similar Solid 20 Structures Prominent Buildings and Similar Extensive 21 Obstructions 1• Alternate Methods of Displaying Obstruction 22 Lights Page vi
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CHAPTER 6. HIGH INTENSITY OBSTRUCTION LIGHTING STANDARDS 23
17. Standards for Lighting Obstructions to Air Navigation with High Intensity White Obstruction Lights 23
a. High Intensity Obstruction Lights C• b. Light Specifications Flashtube Replacements 23 23
d. Installation Guidance 24 e• High Intensity Ligh Units 24 £ • Relocation or Omission of Light Units 25 8 - Chimneys, Flare Stacks and Similar Solid 26 Structures 27
h. Radio and Television Towers and Similar Skeletal Structures 27 j• 1. Hyperbolic Cooling Towers Supporting Structures of Overhead Trans- 27 mission (Catenary) Lines 28
k. Prominent Buildings, Observation Towers and Similar Extensive Obstructions 30 * 1. Twilight/Nighttime Use Only 31 CHAPTER 7. DUAL LIGHTING SYSTEMS 33
18. Dual Lighting Systems 33 CHAPTER 8. MARKING AND LIGHTING OF MOORED BALLOONS AND KITES 35
19. Purpose
20. Application 35
21. Marking 35
a. Display 35
b. Shape 35
c. Color Patterns 35 35
22. Lighting
a. Display 35
b. Light Distribution 35 35
23. Light Control Device
24. Other Federal or Local Government Regulations 36 36 CHAPTER 9. OBSTRUCTION MARKING AND LIGHTING EQUIPMENT 37
25. Purpose 37 Page vii
AC 70/7460-1F 9/27/78 Page No.
26. Paint 37
a. Colora 37
b. Availability of Specifications 37
27. Lights and Associated Equipment 37
a. Aviation Red Obstruction Lighting System 37
b. High Intensity White Obstruction Lighting 38 Systems
c. Approved Manufacturers 38
d. Installation and Maintenance 38 e • Availability 38
f. Recommended Lamp Equipment 39
ILLUSTRATIONS Page No.
APPENDIX 1.
Figure 1. Types of Obstruction Lights 1 Figure 2. Painting and Lighting of Chimneys, Poles, 2 Towers and Similar Obstructions Figure 3. Painting and Lighting of Water Towers, 3 Storage Tanks and Similar Obstructions Figure 4. Painting and Lighting of Water Towers and 4 Similar Obstructions Figure 5. Painting of Single Pedestal Water Towers 5 by Teardrop Pattern Figure 6. Examples of Installation of High Intensity 6 Obstruction Lights on Chimneys Figure 7. Same as above Figure 8. Same as above Figure 9. Hyperbolic Cooling Tower Figure 10. Bridge Lighting Page viii
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APPENDIX 2.
Standards for Lighting Towers, Chimneys, Poles and Similar Obstructions with Aviation Red Obstruction Lights - Night Figure 1. 150 feet (46m) to 900 feet (275m) AGL 1 Figure 2. 900 feet (275m) to 1,500 feet (458m) AGL 2 Figure 3. 1,500 feet (458m) to 2,100 feet (641m) AGL 3 Standards for Lighting Chimneys and Similar Solid Lights - Day and Light Obstructions with High Intensity White Obstruction Figure 4. 150 feet (46m) to 900 feet (275m) AGL 4 Figure 5. 900 feet (275m) to 1,500 feet (458m) AGL 5 Figure 6. 1,500 feet (458m) to 2,100 feet (641m) AGL 6 Standards for Lighting Towers and Similar Skeletal Obstructions with High Intensity White Obstruction Lights - Day and Might Figure 7. 150 feet (46m) to 900 feet (275m) AGL 7 Figure 8. 900 feet (275m) to 1,500 feet (458m) AGL 8 Figure 9. 1,500 feet (458m) to 2,100 feet (641m) AGL 9 Standards for Lighting Solid and Skeletal Obstructions with Dual Lighting Systeems Figure 10. 150 feet (46m) to 900 feet (275m) AGL 10 Figure 11. 900 feet. (275m) to 1,500 feet (458m) AGL Figure 12. 1,500 feet (458m) to 2,100 feet (641m) AGL 12 rage ix
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 conmerce.
3. FEDERAL COMUNICATIONS 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. 1 378-778 0 - 78 - 2 Page 1 (and 2)
CHAPTER 2. GENERAL, RECOMMENDATIONS 4• OBJECTS TO BE MARKED AND LIGHTED. When any object or portion thereof, site level or any standard for determining obstructions set forth in either temporary or permanent, exceeds a height of 200 feet (61m) above that the absence of such marking and/or lighting will not impair safety as lights, rods, antennas, etc. to air navigation. The overall height includes all appurtenances such (14 CFR 77), that object should be marked and lighted exactly in Section 77.13 or Subpart C of Part 77 of the Federal Aviation Regulations be nost conspicuous. An FAA aeronautical study, however, may determine accordance with the applicable standards described herein in order to
5. 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 permitted. The final determination for acceptable level of safety is achieved. a modification or deviation must be based on a study showing that an 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:
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 No marking and/or 11ghting. The object may be so located with respect to other objects or terrain, so removed from the general flow of air traffic, or go conspicuous would serve no useful purpose. by its shape, size or color that marking or lighting
(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• Chap. 2 Par. 4 Page 3