white

capacitor discharge omnidirectional light which conforms to FAA/DOD Specification L-856, High Intensity Obstruction Lighting Systems, shall be mounted on the highest point. If the antenna or similar appurtenance is incapable of supporting the omnidirectional light, one or

more

lights shall be installed on a suitable adjacent support with the light(s) mounted no more than 6.10 meters (20 feet) below the tip of the appurtenance. The light(s) shall be positioned so as to permit unobstructed viewing of at least one light from aircraft at any normal angle of approach. The light unit(s) shall emit a beam peak intensity around its periphery of approximately 20,000 candelas during daytime and twilight operation, and approximately 4,000 candelas at night.

(d) All lights shall be synchronized to flash simultaneously at 40 pulses per minute. The light system shall be equipped with a light sensitive control device which shall face the north sky and cause the intensity steps to change automatically when the north sky illumination on a vertical surface is as follows:

(1) Day to twilight. This shall not occur before the illumination drops to 645.84 lux (60 fc), but shall occur before it drops below 322.92 lux (30 fc).

(2) Twilight to night. This shall not occur before the illumination drops to 53.82 lux (5 fc), but shall occur before it drops below 21.53 lux (2 fc).

(3) Night to day. The intensity changes listed in paragraphs (d) (1) and (2) of this section shall be reversed in transitioning from the night to day modes.

Failure of the intensity step changing circuits shall cause all lights to operate in the high intensity mode or the next brighter intensity step above that required for the period of operation.

[40 FR 30265, July 18, 1975, as amended at 42 FR 54826, Oct. 11, 1977]

$17.41 Specifications for the high intensity lighting of antenna structures having a skeletal tower over 182.88 meters (600 feet) up to and including 304.80 meters (1,000 feet) in height.

Antenna structures having a skeletal tower or other main support structures

over 182.88 meters (600 feet) up to and including 304.80 meters (1,000 feet) in height shall be obstruction lighted as follows:

(a) There shall be installed at the top of the skeletal tower or other main support structure three or more high intensity light units which conform to FAA/DOD Specification L-856, High Intensity Obstruction Lighting Systems. The complement of units shall emit a white high intensity light and produce an effective intensity of not less than 200,000 candelas (daytime) uniformly about the antenna structure in the horizontal plane. The effective intensity shall be reduced to approximately 20,000 candelas at twilight, and to approximately 4,000 candelas at night. The light units shall be mounted in a manner to insure unobstructed viewing from aircraft at any normal angle of approach and so that the effective intensity of the full beam is not impaired by any structural members of the skeletal framework. The units will normally be adjusted so that the center of the beam is in the horizontal plane.

(b) At the approximate and levels of the skeletal tower there shall be installed additional sets of high intensity obstruction lights as in paragraph (a) of this section. The normal angular adjustment of the beam centers above the horizontal shall be 2 degrees at the 1⁄2 level and one degree at the level. See Table under § 17.42.

(c) Where a rod or similar appurtenance extends more than 6.10 meters (20 feet) above the skeletal tower or other main support structure, a white capacitor discharge omnidirectional light which conforms to FAA/DOD Specification L-856, High Intensity Obstruction Lighting Systems, shall be mounted on the highest point. If the antenna or similar appurtenance is incapable of supporting the omnidirectional light, one or more lights shall be installed on a suitable adjacent support with the light(s) mounted no more than 6.10 meters (20 feet) below the tip of the appurtenance. The light(s) shall be positioned so as to permit unobstructed viewing of at least one light from aircraft at any normal angle of approach. The light unit(s) shall emit a beam peak intensity around its periphery of approximately

341-180 0-93-20

20,000 candelas during daytime and twilight operation, and approximately 4,000 candelas at night.

(d) All lights shall be synchronized to flash simultaneously at 40 pulses per minute. The light system shall be equipped with a light sensitive control device which shall face the north sky and cause the intensity steps to change automatically when the north sky illumination on a vertical surface is as follows:

(1) Day to twilight. This shall not occur before the illumination drops to 645.84 lux (60 fc), but shall occur before it drops below 322.92 lux (30 fc).

(2) Twilight to night. This shall not occur before the illumination drops to 53.82 lux (5 fc), but shall occur before it drops below 21.53 lux (2 fc).

(3) Night to day. The intensity changes listed in paragraphs (d) (1) and (2) of this section shall be reversed in transitioning from the night to day modes.

Failure of the intensity step changing circuits shall cause all lights to operate in the high intensity mode or the next brighter intensity step above that required for the period of operation.

[40 FR 30266, July 18, 1975, as amended at 42 FR 54826, Oct. 11, 1977; 42 FR 56608, Oct. 27, 1977]

$17.42 Specifications for the high intensity lighting of antenna structures having a skeletal tower over 304.80 meters (1,000 feet) in height. Antenna structures having a skeletal tower or other main support structure over 304.80 meters (1,000 feet) in height shall be obstruction lighted as follows:

(a) There shall be installed at the top of the skeletal tower or other main support structure three or more high intensity light units which conform to FAA/DOD Specification L-856, High Intensity Obstruction Lighting Systems. The complement of units shall emit a white high intensity light and produce an effective intensity of not less than 200,000 candelas (daytime) uniformly about the antenna structure in the horizontal plane. The effective intensity shall be reduced to approximately 20,000 candelas at twilight, and to approximately 4,000 candelas at night. The light units shall be mounted in a manner to insure unobstructed viewing

from aircraft at any normal angle of approach and so that the effective intensity of the full beam is not impaired by any structural members of the skeletal framework. The units will normally be adjusted so that the center of the beam is in the horizontal plane.

(b) In addition, there shall be installed at approximate equi-distant levels along the vertical axis of the skeletal tower three or more sets of high intensity obstruction lights as in paragraph (a) of this section. Three intermediate levels are required for skeletal towers over 304.80 meters (1,000 feet) up to and including 426.72 meters (1,400 feet). For each additional 121.92 meters (400 feet) or fraction one additional level of lighting shall be installed. The normal angular adjustment of the beam centers at the bottom level shall be 3 degrees above the horizontal and for the second progressive level shall be 2 degrees above the horizontal. For other progressive levels, see Table below.

(c) Where a rod or similar appurtenance extends more than 6.10 meters (20 feet) above the skeletal tower or other main support structure, a white capacitor discharge omnidirectional light which conforms to FAA/DOD Specification L-856, High Intensity Obstruction Lighting Systems, shall be mounted on the highest point. If the antenna or similar appurtenance is incapable of supporting the omnidirectional light, one or more lights shall be installed on a suitable adjacent support with the light(s) mounted no more than 6.10 meters (20 feet) below the tip of the appurtenance. The light(s) shall be positioned so as to permit unobstructed viewing of at least one light from aircraft at any normal angle of approach. The light unit(s) shall emit a beam peak intensity around its periphery of approximately 20,000 candelas during daytime and twilight operation, and approximately 4,000 candelas at night.

(d) All lights shall be synchronized to flash simultaneously at 40 pulses per minute. The light system shall be equipped with a light sensitive control device which shall face the north sky and cause the intensity steps to change automatically when the north sky illu

mination on a vertical surface is as follows:

(1) Day to twilight. This shall not occur before the illumination drops to 645.84 lux (60 fc), but shall occur before it drops below 322.92 lux (30 fc).

(2) Twilight to night. This shall not occur before the illumination drops to 53.82 lux (5 fc), but shall occur before it drops below 21.53 lux (2 fc).

(3) Night to day. The intensity changes listed in paragraphs (d) (1) and (2) of this section shall be reversed in transitioning from the night to day modes.

Failure of the intensity step changing circuits shall cause all lights to operate in the high intensity mode or the next brighter intensity step above that required for the period of operation.

§ 17.43 Painting and lighting of new and existing structures.

(a) The provisions of this part of the rules with respect to antenna structures required to be painted and/or lighted, shall be effective November 1, 1970, for any new antenna structure and for any change in the height or location of an existing antenna structure.

(b) All existing antenna structures required to be painted shall be painted in the manner set forth in § 17.23 at the time when the antenna structure is repainted (see § 17.50) or in no event later than November 1, 1977.

(c) All existing antenna structures required to be illuminated shall be brought into conformity herewith within 6 months after September 5, 1970, at any station for which the authorization is renewable on or prior to that date, and within 3 months following the renewal of an authorization renewable after September 5, 1970.

(d) Nothing in the notification criteria concerning antenna structures or locations, as set forth in subpart B of this part, shall apply to painting and lighting those structures authorized prior to September 5, 1967, except where lighting and painting requirements are reduced, in which case the lesser requirements may apply upon approval of an application to the Commission for such reduction.

[35 FR 16404, Oct. 21, 1970]

$17.45 Temporary warning lights.

During construction of an antenna structure, for which red obstruction lighting is required, at least two 116- or 125-watt lamps (A21/TS) enclosed in aviation red obstruction light globes, shall be installed at the uppermost point of the structure. The intensity of each lamp shall not be less than 32.5 candelas. In addition, as the height of the structure exceeds each level at which permanent obstruction lights will be required, two similar lights shall be installed at each such level. These temporary warning lights shall be displayed nightly from sunset to sunrise until the permanent obstruction lights have been installed and placed in operation, and shall be positioned so as to insure unobstructed visibility of at least one of the lights at any normal angle of approach. If practical, the permanent obstruction lights may be installed and operated at each required level as construction progresses.

[32 FR 11273, Aug. 3, 1967, as amended at 39 FR 26157, July 17, 1974; 42 FR 54826, Oct. 11, 1977]

§ 17.47 Inspection of tower lights and associated control equipment.

The licensee of any radio station which has an antenna structure requiring illumination pursuant to the provisions of section 303(q) of the Communications Act of 1934, as amended, as outlined elsewhere in this part:

(a)(1) Shall make an observation of the tower lights at least once each 24 hours either visually or by observing an automatic properly maintained indicator designed to register any failure of such lights, to insure that all such

lights are functioning properly as required; or alternatively,

(2) Shall provide and properly maintain an automatic alarm system designed to detect any failure of such lights and to provide indication of such failure to the licensee.

(b) Shall inspect at intervals not to exceed 3 months all automatic or mechanical control devices, indicators, and alarm systems associated with the tower lighting to insure that such apparatus is functioning properly.

[32 FR 11273, Aug. 3, 1967]

§ 17.48 Notification of extinguishment or improper functioning of lights.

The licensee of any radio station which has an antenna structure requiring illumination pursuant to the provisions of section 303(q) of the Communications Act of 1934, as amended, as outlined elsewhere in this part:

(a) Shall report immediately by telephone or telegraph to the nearest Flight Service Station or office of the Federal Aviation Administration any observed or otherwise known extinguishment or improper functioning of any top steady burning light or any flashing obstruction light, regardless of its position on the antenna structure, not corrected within 30 minutes. Such reports shall set forth the condition of the light or lights, the circumstances which caused the failure, and the probable date for restoration of service. Further notification by telephone or telegraph shall be given immediately upon resumption of normal operation of the light or lights.

(b) An extinguishment or improper functioning of a steady burning side intermediate light or lights, shall be corrected as soon as possible, but notification to the FAA of such extinguishment or improper functioning is not required.

Outside white

Aviation surface orange

Aviation surface orange, enamel

Aviation red obstruction light-color Flashing beacons

Do

Double and single obstruction light

Do

High intensity white obstruction light

116-Watt lamp

125-Watt lamp

620-Watt lamp

[32 FR 11273, Aug. 3, 1967, as amended at 39 FR 26157, July 17, 1974; 40 FR 30267, July 18, 1975]

$17.49 Recording of tower light inspections in the station record.

The licensee of any radio station which has an antenna structure requiring illumination must make the following entries in the station record in the event of any observed or otherwise known extinguishment or improper functioning of a tower light:

(a) The nature of such extinguishment or improper functioning.

(b) The date and time the extinguishment or improper operation was observed or otherwise noted.

(c) The date, time and nature of adjustments, repairs or replacements made.

[48 FR 38477, Aug. 24, 1983]

700-Watt lamp

No. 700 PS-40 (6,000 h).

$17.54 Rated lamp voltage.

To insure the necessary lumen output by obstruction lights, the rated voltage of incandescent lamps used shall correspond to be within 3 percent higher than the voltage across the lamp socket during the normal hours of operation.

[42 FR 54826, Oct. 11, 1977]

$17.56 Maintenance of lighting equipment.

(a) Replacing or repairing of lights, automatic indicators or automatic control or alarm systems shall be accomplished as soon as practicable.

(b) The flash tubes in a high intensity obstruction lighting system shall be replaced whenever the peak effective daytime intensity falls below 200,000 candelas.

[40 FR 30267, July 18, 1975]

$17.57 Report of radio transmitting antenna construction, alteration, and/or removal.

Any permittee or licensee who, pursuant to any instrument of authorization from the Commission to erect or make changes affecting antenna height or location of an antenna tower for which obstruction marking or lighting is required shall, prior to start of tower construction and upon completion of such construction or changes, fill out and file with the Aeronautical Chart Division of the National Ocean Survey, NOAA Form 76-10 (Report of Radio Transmitting Antenna Construction, Alteration and/or Removal) in order that antenna tower information may be provided promptly for use on aeronautical charts and related publications in the interest of safety in air navigation.

[39 FR 7581, Feb. 27, 1974]