4.4 Catenary Lighting4-2
4.5 Inspection, Repair and Maintenance4-3
4.6 Nonstandard Lights4-3
4.7 Placement Factors4-3
4.8 Monitoring Obstruction Lights4-4
4.9 Ice Shields4-5
4.10 Light Shields4-5
4.11 Distraction4-5
CHAPTER 5. RED OBSTRUCTION LIGHT SYSTEM5-1
5.1 Purpose5-1
5.2 Standards5-1
5.3 Control Device5-2
5.4 Poles, Towers and Similar Skeletal Structures5-2
5.5 Chimneys, Flare Stacks and Similar Solid Structures5-3
5.6 Group of Obstructions5-4
5.7 Alternate Method of Displaying Obstruction Lights5-4
5.8 Prominent Buildings, Bridges and Similar Extensive Obstructions5-4
CHAPTER 6. MEDIUM-INTENSITY FLASHING WHITE OBSTRUCTION LIGHT
SYSTEMS6-1
6.1 Purpose6-1
6.2 Standards6-1
6.3 Radio and Television Towers and Similar Skeletal Structures6-1
6.4 Control Device6-2
6.5 Chimneys, Flare Stacks and Similar Solid Structures6-3
6.6 Group of Obstructions6-3
6.7 Special Cases6-3
6.8 Prominent Buildings and Similar Extensive Obstructions6-3
CHAPTER 7. HIGH-INTENSITY FLASHING WHITE OBSTRUCTION LIGHT
SYSTEMS7-1
7.1 Purpose7-1
7.2 Standards7-1
7.3 Control Device7-1
7.4 Units per Level7-2
7.5 Installation Guidance7-2
7.6 Antenna or Similar Appurtenance Light7-3
7.7 Chimneys, Flare Stacks and Similar Solid Structures7-3
7.8 Radio and Television Towers and Similar Skeletal Structures7-4
7.9 Hyperbolic Cooling Towers7-4
7.10 Prominent Buildings and Similar Extensive Obstructions7-5
CHAPTER 8. DUAL LIGHTING WITH RED/MEDIUM-INTENSITY FLASHING WHITE
LIGHT SYSTEMS8-1
8.1 Purpose8-1
8.2 Installation8-1
8.3 Operation8-1
8.4 Control Device8-1
8.5 Antenna or Similar Appurtenance Light8-1
8.6 Omission of Marking8-2
CHAPTER 9. DUAL LIGHTING WITH RED/HIGH-INTENSITY FLASHING WHITE
LIGHT SYSTEMS9-1
9.1 Purpose9-1
9.2 Installation9-1
9.3 Operation9-1
9.4 Control Device9-1
9.5 Antenna or Similar Appurtenance Light9-1
9.6 Omission of Marking9-2
CHAPTER 10. MARKING AND LIGHTING OF CATENARY AND CATENARY
SUPPORT STRUCTURES10-1
10.1 Purpose10-1
10.2 Catenary Marking Standards10-1
10.3 Catenary Lighting Standards10-3
10.4 Control Device10-4
10.5 Area Surrounding Catenary Wire Support Structures10-5
10.6 Three or More Catenary Wire Support Structures10-5
10.7 Adjacent Catenary Structures10-5
CHAPTER 11. MARKING AND LIGHTING MOORED BALLOONS AND KITES11-1
11.1 Purpose11-1
11.2 Standards11-1
11.3 Marking11-1
11.4 Purpose11-1
11.5 Operational Characteristics11-2
CHAPTER 12. MARKING AND LIGHTING EQUIPMENT AND INFORMATION12-1
12.1 Purpose12-1
12.2 Paint Standard12-1
12.3 Availability of Specifications12-2
12.4 Lights and Associated Equipment12-2
12.5 Availability12-3
CHAPTER 13. MARKING AND LIGHTING WIND TURBINES13-1
13.1 Purpose13-1
13.2 General Standards13-1
13.3 Wind Turbine Configurations13-1
13.4 Marking Standards13-1
13.5 Lighting Standards13-2
13.6 Wind Turbines Above 499 Feet13-4
13.7 Wind Turbines at or Above 699 Feet (213 m)13-4
13.8 Lighting of Wind Turbines During Construction Phase13-5
13.9 Lighting and Marking of Airborne Wind Turbines13-5
13.10 Lighting and Marking of Offshore Wind Turbines13-5
CHAPTER 14. AIRCRAFT DETECTION LIGHTING SYSTEMS14-1
14.1 Purpose14-1
14.2 General Standards14-1
14.3 Voice/Audio Option14-3
APPENDIX AA-1
APPENDIX BB-1
1-1 CHAPTER 1. ADMINISTRATIVE AND GENERAL PROCEDURES
1.1 Reporting Requirements.
A sponsor proposing any type of construction or alteration of a structure that may affect the NAS as required under the provisions of Title 14 Code of Federal Regulations (CFR) Part 77, Construction or alteration requiring notice, is to notify the Federal Aviation Administration (FAA) by completing the Notice of Proposed Construction or Alteration form (FAA Form 7460-1). This form should be filed electronically at http://oeaaa.faa.gov.
1.2 Preconstruction Notice.
The notice must be submitted:
1. At least 45 days prior to the date of proposed construction or alteration is to begin.
2. On or before the date an application for a construction permit is filed with the Federal Communications Commission (FCC). (The FCC advises its applicants to file with the FAA well in advance of the 45-day period to expedite FCC processing.)
1.3 FAA Acknowledgement.
The FAA will acknowledge, in writing, each FAA Form 7460-1 notice received.
1.4 Supplemental Notice Requirement.
1. If required, the FAA will include a statement requiring the filing of FAA Form 7460-2, Notice of Actual Construction or Alteration, on the determination. All FAA Forms 7460-2 should be filed electronically at http://oeaaa.faa.gov.
2. FAA Form 7460-2 Part 1 is to be completed and sent to the FAA at least 10 days prior to starting the actual construction or alteration of a structure. Part 2 shall be submitted within 5 days after the structure has reached its greatest height. The form should be filed electronically at http://oeaaa.faa.gov.
3. In addition, a supplemental notice shall be submitted upon abandonment of construction.
4. Letters are acceptable in cases where the construction/alteration is temporary or a proposal is abandoned. This notification process gives the FAA the necessary time to change effected procedures and/or minimum flight altitudes and to otherwise alert airmen of the structure’s presence.
Note: Notification, as required in the determination, is critical to aviation safety.
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1.5 Modifications and Deviations.
Requests for modification or deviation from the standards outlined in this AC must be submitted to the FAA Obstruction Evaluation Group (OEG). The sponsor is responsible for adhering to approved marking and/or lighting limitations, and/or recommendations given, and should notify the FAA and FCC (for those structures regulated by the FCC) prior to removal of marking and/or lighting. A request received after a determination is issued may require a new study and could result in a new determination.
1. Modification Examples. Modifications will be based on whether they impact aviation safety. Examples of modifications are as follows:
a. Marking and/or Lighting Only a Portion of an Object. The object may be located with respect to other objects or terrain that only a portion of it needs to be marked or lighted.
b. No Marking and/or Lighting. The object may be located with respect to other objects or terrain, removed from the general flow of air traffic, or may be so conspicuous by its shape, size or color that marking or lighting would serve no useful purpose.
c. Voluntary Marking and/or Lighting. The object may be located with respect to other objects or terrain that the sponsor feels increased conspicuity would better serve aviation safety. Sponsors who desire to voluntarily mark and/or light their structure should do so in accordance with this AC.
d. Marking or Lighting an Object in Accordance with the Standards for an Object of Greater Height or Size. The object may present such an extraordinary hazard potential that higher standards may be recommended for increased conspicuity to ensure aviation safety.
2. Deviations. The assigned Obstruction Evaluation Specialist will conduct an aeronautical study of the proposed deviation(s) and forward their recommendation to FAA Headquarters, OEG Manager, in Washington, DC, for final approval.
Examples of deviations that may be considered:
a. Colors of objects.
b. Dimensions of color bands or rectangles.
c. Colors/types of lights.
d. Basic signals and intensity of lighting.
e. Night/day lighting combinations.
f. Flash rate.
3. The FAA strongly recommends that owners become familiar with the different types of lighting systems and to specifically request the type of lighting system desired when submitting FAA Form 7460-1. Information on these systems is given in Table A-1 in Appendix A. While the FAA will make every effort to accommodate the structure sponsor’s request, sponsors should also request
1-3 information from system manufacturers to determine which system best meets their needs based on purpose, installation, and maintenance costs.
1.6 Additional Notification.
Any change to the submitted information on which the FAA has based its determination, including modification, deviation, or optional upgrade to white lighting on structures, may require notice to the FCC prior to making the change for proper authorization and annotations of obstruction marking and lighting. These structures may be subject to inspection and enforcement of marking and lighting requirements by the FCC. FCC Forms and Bulletins can be obtained from the FCC’s National Call Center at 1-888-CALL-FCC (1-888-225-5322) or online at http://www.fcc.gov/forms.
Upon completion of the actual change, complete the “Add Supplemental Notice (7460-2 Form)” at the http://oeaaa.faa.gov website. You may also mail the FAA Form 7460-2 to:
FAA Aeronautical Information Services 1305 E W Hwy Silver Spring, MD 20910 1-800-626-3677
2-1 CHAPTER 2. GENERAL
2.1 Structures to be Marked and Lighted.
Any temporary or permanent structure, including all appurtenances, that exceeds an overall height of 200 feet (61 m) above ground level (AGL) or exceeds any obstruction standard contained in 14 CFR Part 77 should be marked and/or lighted. However, an FAA aeronautical study may reveal that the absence of marking and/or lighting will not impair aviation safety. Conversely, the object may present such an extraordinary hazard potential that higher standards may be recommended for increased conspicuity to ensure aviation safety. In general, commercial outside lighting should not be used in lieu of FAA-recommended marking and/or lighting. Recommendations on marking and/or lighting structures can vary, depending on terrain features, weather patterns, geographic location, and in the case of wind turbines, the number of structures and overall design layout. The FAA may also recommend marking and/or lighting a structure that does not exceed 200 (61 m) feet AGL or 14 CFR Part 77 standards because of its particular location. The marking and lighting configurations are illustrated in Appendix A, Figures A-1 through A-27.
2.2 Guyed Structures.
The guys of a 2,000-foot (610-m) skeletal tower are anchored between 1,600 feet (488 m) and 2,000 feet (610 m) from the base of the structure. This places a portion of the guys 1,500 feet (458 m) from the tower at a height of between 125 feet (38 m) and 500 feet (153 m) AGL. Title 14 CFR Part 91, Section 119, requires pilots, when operating over other than congested areas, to remain at least 500 feet (153 m) from man-made structures. Therefore, the tower must be cleared by 2,000 feet (610 m) horizontally to avoid all guy wires. Properly maintained marking and lighting are important for increased conspicuity because the guys of a structure are difficult to see until the aircraft is dangerously close.
2.3 Marking and Lighting Equipment.
Considerable effort and research was expended to determine the minimum marking and lighting systems or quality of materials that will produce an acceptable level of aviation safety. The FAA will recommend only those marking and lighting systems that meet established technical standards. While additional lights may be desirable to identify an obstruction to air navigation and may, on occasion, be recommended, the FAA will recommend minimum standards in the interest of safety, economy, and related concerns. Therefore, to provide an adequate level of safety, obstruction lighting systems should be installed, operated, and maintained in accordance with the recommended standards herein. Table A-1 in Appendix A contains descriptions of each FAA-approved obstruction lighting fixture that is referred to in this AC.
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2.4 Light Failure Notification.
2.4.1 Sponsors should consider that conspicuity is achieved only when all recommended lights are working. Partial equipment outages decrease the margin of safety. Any outage should be corrected as soon as possible. Failure of steady-burning side or intermediate lights should be corrected as soon as possible, but notification is not required.
2.4.2 Any failure or malfunction that lasts more than thirty (30) minutes and affects a top light or flashing obstruction light, regardless of its position, should be reported immediately by calling Outage Reporting and Notice to Airmen (NOTAM) 877-487- 6867, or for Alaska 800-478-3576, so a NOTAM can be issued. Lights that are voluntary (not required by an FAA determination) do not require a NOTAM. For structures that are regulated by the FCC, the FCC advises that noncompliance with notification procedures could subject the sponsor to penalties or monetary forfeitures.
2.4.3 The following information should be specified for outage reporting:
1. Name of persons or organizations reporting the light failures, including any title, address, and telephone number.
2. The type of structure.
3. Location of structure (including latitude and longitude, if known, prominent structures, landmarks, etc.).
4. Height of structure AGL/above mean sea level (AMSL) if known.
5. A return to service date.
6. FCC Antenna Structure Registration Number (for structures that are regulated by the FCC).
Note 1: When the primary lamp in a double obstruction light fails, and the secondary lamp comes on, no report is required.
Note 2: After 15 days, the NOTAM is automatically deleted from the system. The sponsor is responsible for calling outage reporting to extend the outage date or to report a return to service date.
2.5 Notification of Restoration.
As soon as normal operation is restored, notify outage reporting. For structures that are regulated by the FCC, the FCC advises that noncompliance with notification procedures could subject the sponsor to penalties or monetary forfeitures.
2.6 Federal Communications Commission (FCC) Requirement.
The use of a high-intensity flashing white lighting system on structures located in residential neighborhoods (as defined by applicable zoning laws) trigger requirements for FCC licenses and an environmental assessment.
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2.7 Voluntary Marking of Meteorological Evaluation Towers (METs) Less Than 200 Feet (61 m) AGL.
2.7.1 Recommendation.
The FAA recommends voluntary marking of METs less than 200 feet (61 m) AGL in accordance with marking guidance contained in this advisory circular (AC).
Historically, this guidance has not been applied. However, the FAA recognizes the need to address safety impacts to low-level agricultural flight operations, and it believes that voluntarily marking METs less than 200 feet (61 m) AGL in remote and rural areas enhance the conspicuity of these structures.
2.7.2 Painting.
METs should be painted in accordance to the criteria contained in Chapter 3, paragraphs 3.1 through 3.4, specifically, with alternate bands of aviation orange and white paint. In addition, paragraph 3.5 states that all markings should be replaced when faded or otherwise deteriorated.
2.7.3 High-Visibility Sleeves.
It is recommended that several high-visibility sleeves be installed on the MET’s outer guy wires. One high-visibility sleeve should be installed on each guy wire, as close to the anchor point as possible, but at a, height well above the crop or vegetation canopy.
A second sleeve should be installed on the same outer guy wires midway between the location of the lower sleeve and the upper attachment point of the guy wire to the MET.
2.7.4 Spherical Markers.
It is also recommended that high-visibility aviation orange spherical marker (or cable) balls be attached to the guy wires. Spherical markers should be installed and displayed in accordance to Chapter 3, paragraph 3.5. The FAA, however, recognizes various weather conditions and manufacturing placement standards may affect the placement and use of high-visibility sleeves and/or spherical markers. Thus, some flexibility is allowed when determining sleeve length and marker placement on METs.
2.8 Obstruction Height Definition Changed to 499 Feet AGL.
Because of changes made to 14 CFR Part 77, Safe, Efficient Use, and Preservation of the Navigable Airspace, on July 21, 2010, the height of a structure (identified as an obstruction) was lowered to 499 feet AGL from 500 feet AGL. Consequently, all structures that are above 499 feet AGL will be designated as obstructions. The FAA will conduct an aeronautical study to determine the effect on navigable airspace. This will ensure all usable airspace at and above 500 feet AGL is addressed during the study and the airspace is safe for air navigation.
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CHAPTER 3. MARKING GUIDELINES
3.1 Purpose.
This chapter provides recommended guidelines to make certain structures conspicuous to pilots during daylight hours. One way to achieve this conspicuity is to paint and/or mark these structures. Recommendations on marking structures can vary, depending on terrain features, weather patterns, geographic location, and the number of structures.
Specific marking guidelines for wind turbines are contained in Chapter 13.
3.2 Paint Colors.
Alternate sections of aviation orange and white paint should be used as the contrast in colors provides maximum visibility of an obstruction. Specific paint standards are contained in Chapter 12.
3.3 Paint Standards.
To be effective, the paint used should meet specific color requirements when freshly applied to a structure. Because all outdoor paints deteriorate with time, and it is not practical to give a maintenance schedule for all climates, surfaces should be repainted when the color changes noticeably or its effectiveness is reduced by scaling, oxidation, chipping, or layers of contamination. The subsequent standards should be followed.
3.3.1 Materials and Application.
The FAA recommends that quality paint and materials be selected to maximize years of service. The paint should be appropriate for the surfaces to be painted, including any previous coatings, and suitable for the environmental conditions. Surface preparation and paint application should follow the manufacturer’s recommendations.
Note: In-Service Aviation Orange Color Tolerance Charts are available from private suppliers for determining when repainting is required. The color should be sampled on the upper half of the structure, since weathering is greater there.
3.3.2 Surfaces not Requiring Paint.
Ladders, decks, and walkways of steel towers and similar structures do not need to be painted if a smooth surface presents a potential hazard to maintenance personnel.
Painting may also be omitted from precision or critical surfaces if the paint would have an adverse effect on the transmission or radiation characteristics of a signal. However, the structure’s overall marking effect should not be reduced.
3.3.3 Skeletal Structures.
Complete all marking/painting prior to or immediately upon completion of construction.
This applies to catenary support structures, radio and television towers, and similar skeletal structures. To be effective, paint should be applied to all inner and outer surfaces of the framework.
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3.4 Paint Patterns.
Various types of paint patterns are used to mark structures. The pattern is determined by the size and shape of the structure. The following patterns are recommended.
3.4.1 Solid Pattern.
Obstacles should be painted aviation orange if the structure’s horizontal and vertical dimensions do not exceed 10.5 feet (3.2 m).
3.4.2 Checkerboard Pattern.
Alternating rectangles of aviation orange and white are normally displayed on the following structures:
1. Water, gas, and grain storage tanks.
2. Buildings, as required.
3. Large structures exceeding 10.5 feet (3.2 m) across, having a horizontal dimension that is equal to or greater than the vertical dimension.
3.4.3 Size of Patterns.
The sides of the checkerboard pattern should measure not less than 5 feet (1.5 m) or more than 20 feet (6 m) and should be as nearly square as possible. However, if it is impractical because of the size or shape of a structure, the sides of the patterns may be less than 5 feet (1.5 m). When possible, the corner surfaces should be painted aviation orange. (See Figures A-15 and A-16 in Appendix A.)
3.4.4 Alternate Bands.
Alternate bands of aviation orange and white are normally displayed on the following structures:
1. Communication towers and catenary support structures.
2. Poles.
3. Smokestacks.
4. Skeletal framework of storage tanks and similar structures.
5. Structures that appear narrow from a side view are 10.5 feet (3.2 m) or more across, and the horizontal dimension is less than the vertical dimension.
6. Coaxial cable, conduits, and other cables attached to the face of a tower.
3.4.5 Color Band Characteristics.
Bands for structures of any height should be:
1. Equal in width, provided each band is not less than 1 1/2 feet (0.5 m) or more than 100 feet (31 m) wide.
2. Perpendicular to the vertical axis with the bands at the top and bottom painted orange.
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3. An odd number of bands on the structure.
4. Approximately one-seventh the height, if the structure is equal to or less than 700 feet (214 m) AGL. For each additional 200 feet (61 m) or fraction thereof, add one
(1) additional orange and one (1) additional white band. Table 3-1 shows the required band widths based on the height of the structure.
5. Equal and in proportion to the structure’s AGL height.
Table 3-1. Structure Height to Bandwidth Ratio Example: If a structure is:
Greater Than Equal to or Less Than Band Width
10.5 feet (3.2 m) 700 feet (214 m) 1/7 of height 700 feet (214 m) 900 feet (275 m) 1/9 of height 900 feet (275 m) 1,100 feet (336 m) 1/11of height 1,100 feet (336 m) 1,300 feet (397 m) 1/13 of height
3.4.6 Structures With a Cover or Roof.
If the structure has a cover or roof, the highest orange band should be continued to cover the entire top of the structure. (See Figures A-15 and A-16 in Appendix A.)
3.4.7 Skeletal Structures Atop Buildings.
If a flagpole, skeletal structure, or similar object is 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 filed with the FAA determines the width of the color bands.
3.4.8 Partial Marking.
If marking is recommended for only a portion of a structure because the structure is shielded 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.
3.4.9 Teardrop Pattern.
Spherical water storage tanks with a single, circular standpipe support may be marked in a teardrop-striped pattern. 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 (1.5 m) nor more than 15 feet
(4.6 m). (See Figure A-17 in Appendix A.)
3.4.10 Community Names.