1 Jan 72 AC 70/7460-1A
c. RECOMMENDED LAMP EQUIPMENT Multiple Circuits Volts Average Typical or Rated Lab. Approx. Specifications Service watts Amps. Bulb Base Life (Hours) Lumens FAA MIL Double & 125 120V A-21 Md. Pf. 6,000 1,220 Single I-7830 Lights Obstruction 116 120V A-21 Md. Ser. 6,000 1,260 I-810 I-7830 Airport 1,000 120V 1-20 Mg. Bip. 500 20,500 291 Beacon 1,200 115V T-20 Mg. Bip. 750 27,500 L-7158 Beacon Code 700 120V PS-40 Mg. PI. 6,000 11,200 L-6273 620 120V PS-40 Mg. PI. 3,000 21,200 446 I-6273 * High Intensity 440V 240V L-856 White 120V Obstruction Lights Series Circuit Obstruction 6.6A A-21 Md. PI. 2,000 1,020 1-810 1-7830 Lights Copies of military specifications may be obtained by contacting Armed Service Electro-Standards Agency, Fort Monmouth, New Jersey 07703 or the Naval Air Systems Command, Department of the Navy, 1411 Jefferson Davis Highway, Arlington, Virginia 20360. Copies of specifications and information concerning Military and Federal specifications may be obtained from Federal Aviation Administration, Washington, D. C., 20591.
var. Page 23 (and 24)
1 Jan 72 AC 70/7460-1A CHAPTER 6. STANDARDS FOR LIGHTING OBSTRUCTIONS TO AIR NAVIGATION WITH
AVIATION RED OBSTRUCTION LIGHTS
17. PURPOSE. To provide the specifications for red obstruction lights to be placed on obstructions to air navigation.
·18. APPLICATION. The general specifications which follow apply to the obstruction lighting of buildings, towers, smokestacks and similar obstructions, except transmission lines and their support structures, For lowers, Smokestacks and Similar Obstructions of all Heights.
There should be installed at the top (or near the top if a smokestack) of the obstruction, in a manner to insure unobstructed visibility of at least one beacon from aircraft at any normal angle of approach, one, or more if required, flashing 300mm electric code beacon(s), each equipped with two lamps and aviation red color filters. The two lamps of the beacon should burn simultaneously and each lamp should be at least 500 watts. (See recommended lamp equipment chart.)
(1) If the obstruction is skeletal by nature, such as a tower, and a rod or other construction of not more than 20 feet in height and incapable of supporting this beacon is mounted on top of the obstruction and it is determined that this additional construction does not permit unobstructed visibility of a single code beacon from any normal angle of approach, there should be installed two such beacons properly positioned to permit unobstructed viewing.
(2) If the obstruction is solid by nature, such as a smokestack, there should be installed two or more such beacons placed at regular intervals on the horizontal plane.
For Towers, Smokestacks and Similar Obstructions of all Heights.
At the top of certain obstructions and at selected levels on other obstructions, there should be installed two or more lights, each light consisting of a lamp of at least 100 watts, enclosed in an aviation red obstruction light globe. These lights should be placed at regular intervals on the horizontal plane in a manner to insure unobstructed visibility of one or more lights on each level from aircraft at any normal angle of approach. * Chap. 6 Par. 17 Page 25
AC 70/7460-1A 1 Jan 72 *
(1) If the structure is skeletal by nature, such as a tower, two the obstruction at each level. ground, lights should be installed on each outside corner of a light should be installed on each corner of the tower at to insure unobstructed visibility of at least one light, or rectangular shaped tower, the lights should be mounted so as visibility of at least one light. In case of a triangular or of the obstruction and mounted so as to insure unobstructed be placed on diagonally or diametrically opposite positions lights should be installed at each level. Each light should On towers more than 450 feet in height above
(2) horizontal plane in a manner to insure unobstructed view of at least two lights on each level. These lights should be placed at regular intervals on the If the obstruction is solid by nature, such as a smokestack, there should be installed at each level at least three lights.
ity of them from aircraft at any normal angle of approach. one or more similar flashing code beacons should be installed in such a position on the obstruction to insure unobstructed visibil- Feet in Overall Height. At selected levels other than the top, For Towers, Smokestacks and Similar Obstructions more than 450 at the prescribed height. beacons. Each beacon should be mounted on the outside of diagonally opposite corners on opposite sides of the structure event this is not possible, there should be installed two such the structural members will not impair its visibility. In the If the obstruction is skeletal by nature, such as a tower, the beacon should be installed within the structure proper so that
19. SPECIFICATIONS. (2) If the obstruction is solid by nature, such as a smokestack, visibility of at least one beacon at each level. on the horizontal plane in a manner to insure unobstructed two or more beacons should be installed at regular intervals
a. Towers, Poles, and Similar Obstructions. when the height of the particular obstruction above ground, or water if so situated, is:
(1) Not more than 150 feet: At the top apply 18b(1).
(2) More than 150 feet but not more than 300 feet: (a) At the top apply 18a(1). (b) At midpoint of the overall height apply 18b(1). * rage 26 Chap. 6 Par. 18
1 Jan 72 AC 70/7460-1A * More than 300 feet but not more than 450 feet:
(a) At the top apply 18a(1).
(b) At approximately two-thirds and one-third of the overall height apply 18b (1).
More than 450 feet but not more than 600 feet:
(a) At the top apply 18a(1).
At approximately one-half of the overall height apply 18c (1).
(c) At approximately three-fourths and one-fourth of the overall height apply 18b (1).
(5) More than 600 feet but not more than 750 feet:
(a) At the top apply 18a(1).
(b) At approximately two-fifths of the overall height apply 18c (1).
(c) At approximately four-fifths, three-fifths, and one-fifth of the overall height apply 18b(1).
(6) More than 750 feet but not more than 900 feet:
(a) At the top apply 18a(1).
(b) At approximately two-thirds and one-third of the overall height apply 18c(1).
At approximately five-sixths, one-halt, and one-sixth of the overall height apply 18b(1).
(7) More than 900 feet but not more than 1050 feet:
(a) At the top apply 18a(1).
(b) At approximately four-sevenths and two-sevenths of the
(c) At approximately six-sevenths, five-sevenths, three-sevenths and one-seventh of the overall height apply 18c(1).
(8) More than 1050 feet but not more than 1200 feet:
At the top apply 18a(1).
At approximately three-fourths, one-half, and one-fourth of the overall height apply 18c(1).
At approximately seven-eighths, five-eighths, threeeighths, and one-eighth of the overall height apply 18b(1)* Chap.
Par. 19 Page 27
AC 70/7460-1A 1 Jan 72 * (9) More than 1200 feet but not more than 1350 feet: (a) At the top apply 18a(1).
(c) (b) At approximately two-thirds, four-ninths, and two-ninths At approximately eight-ninths, seven-ninths, five-ninths, of the overall height apply 18c (1).
18b (1). one-third, and one-ninth of the overall height apply
(10) More than 1350 feet but not more than 1500 feet: (a) At the top apply 18a(1).
(b) At approximately four-fifths, three-fifths, two-fifths, At approximately nine-tenths, seven-tenths, one-half, 18b (1). three-tenths, and one-tenth of the overall height apply and one-fifth of the overall height apply 18c(1).
(11) More than 1500 feet but not more than 1650 feet: (a) At the top apply 18a(1).
(b) At approximately eight-elevenths, six elevenths, four- 18c (1). elevenths and two-elevenths of the overall height apply (* eleventh of the oversi hate spely 185(1) and onen
(12) More than 1650 feet but not more than 1800 feet:
(a) At the top apply 18a(1).
(c) At approximately eleven-twelfths, three-fourths, seven- (b) At approximately five-sixths, two-thirds, one-half, the overall height apply 18b (1). 18c (1). twelfths, five-twelfths, one-fourth, and one-twelfth of one-third, and one-sixth of the overall height apply
(13) More than 1800 feet but not more than 1950 feet: (a) At the top apply 18a(1).
At approximately ten-thirteenths, eight-thirteenths, height apply 18b(1). nine-thirteenths, seven-thirteenths, five-thirteenths, At approximately twelve-thirteenths, eleven-thirteenths, three-thirteenths, and one-thirteenth of the overall of the overall height apply 18c(1). six-thirteenths, four-thirteenths, and two-thirteenths, Page 28 Chap. 6 Par. 19
1 Jan 72 AC 70/7460-1A * (14) More than 1950 feet but not more than 2100 feet:
(a) At the top apply 18a(1).
(b) At approximately six-sevenths, five-sevenths, four- of the overall height apply 18c(1). sevenths, three-sevenths, two-sevenths, and one-seventh
(c) At approximately thirteen-fourteenths, eleven-fourteenths, nine-fourteenths, one-half, five-fourteenths, threetourteenths, and one-fourteenth of the overall height apply 18b(1).
b. Smokestacks and Similar Obstructions. To avoid the obscurant effect of the deposits generally in evidence from this type of structure, the top lights should be installed from 5 to 10 feet below the highest point of the structure. It is important that these lights be readily accessible to enable cleaning when necessary and to facilitate lamp replacements.
(1) Floodlighting. floodlighted by fixed searchlight projectors installed at three or more equidistant points around the base of each Smokestacks and similar obstructions may be obstruction if the searchlight projectors will provide an one-third of the obstruction. average illumination of at least 15 footcandles at the top * (2) When the height of the particular obstruction above ground or water, if so situated is:
(a) Not more than 150 feet: At a near top level apply 18b(2).
(b) More than 150 feet but not more than 300 feet:
At a near top level apply 18a(2) 2 At midpoint of the overall height apply 18b (2).
(c) More than 300 feet but not more than 450 feet:
1 At a near top level apply 18a(2).
At approximately two-thirds and one-third of the overall height apply 18b (2).
(d) More than 450 feet but not more than 600 feet:
1 At a near top level apply 18a(2).
At approximately one-half of the overall height apply At approximately three-fourths and one-fourth of the overall height apply 18b(2). * Chap. 6 Par. 19 Page 29
AC 70/7460-1A 1 Jan 72
(e) More than 600 feet but not more than 750 feet: 2 At approximately two-fifths of the overall height 1 At a near top level apply 18a(2). appiy 18c (2).
At approximately four-fifths, three-fifths and one- fifth of the overall height apply 18b (2).
More than 750 feet but not more than 900 feet:
¿ overall height apply 18c(2). I At approximately two-thirds and one-third of the 1 At a near top level apply 18a(2). At approximately five-sixths, one-half and one-sixth of the overall height apply 18b(2).
(g) More than 900 feet but not more than 1050 feet:
1 At a near top level apply 18a(2).
2 At approximately four-sevenths and two-sevenths of the overall height apply 18c(2).
3 At approximately six-sevenths, five-sevenths, three- 18b (2). sevenths, and one-seventh of the overall height apply
(h) More than 1050 feet but not more than 1200 feet: 1 At a near top level apply 18a(2).
2 At approximately three-fourths, one-half, and one- fourth of the overall height apply 18c(2).
3 At approximately seven-eights, five-eights, three- 18b (2). eights, and one-eighth of the overall height apply
(i) More than 1200 feet but not more than 1350 feet: 1 At a near top level apply 18a(2).
At approximately two-thirds, four-ninths, and two- ninths of the overall height apply 18c(2).
3 At approximately eight-ninths, seven-ninths, fiveapply 18b (2). ninths, one-third, and one-ninth of the overall height
(j) More than 1350 feet but not more than 1500 feet:
2 At approximately four-fifths, three-fifths, two- 1 At a near top level apply 18a(2). 18c (2). fifths, and one-fifth of the overall height apply 3 At approximately nine-tenths, seven-tenths, one-half, apply 18b (2). three-tenths, and one-tenth of the overall height * Page 30 Chap. 6 Par. 19
1 Jan 72 AC 70/7460-1A * (k) More than 1500 feet but not more than 1650 feet:
1 At a near top level apply 18a(2).
2 At approximately eight-elevenths, six-elevenths, four-elevenths, and two-elevenths of the overall height apply 18c(2).
3 At approximately ten-elevenths, nine-elevenths, seven-elevenths, five-elevenths, three-elevenths, and one-eleventh of the overall height apply 18b(2).
(1) More than 1650 feet but not more 1800 feet:
[ At approximately five-sixths, two-thirds, one-half, At a near top level apply 18a(2). 18c (2). one-third, and one-sixth of the overall height apply At approximately eleven-twelfths, three-fourths, seven-twelfths, five-twelfths, one-fourth and onetwelfth of the overall height apply 18b(2).
(m) More than 1800 feet but not more than 1950 feet:
At a near top level apply 18a(2).
2 At approximately ten-thirteenths, eight-thirteenths, six-thirteenths, four-thirteenths, and two-thirteenths of the overall height apply 18c(2).
At approximately twelve-thirteenths, eleven-thirteenths, nine-thirteenths, seven-thirteenths, fivethirteenths, three-thirteenths, and one-thirteenth of the overall height apply 18b (2).
More than 1950 feet but not more than 2100 feet:
. At a near top level apply 18a(2).
At approximately six-sevenths, five-sevenths, fourseventh of the overall height apply 18c(2). sevenths, three-sevenths, two-sevenths, and one- 3 At approximately thirteen-fourteenths, eleventhe overall height apply 18b(2). fourteenths, nine-fourteenths, one-half, five- fourteenths, three-fourteenths, and one-fourteenth of * Chap. 6 Par. 19 Page 31
AC 70/7460-1A 1 Jan 72 Prominent Building and Similar Extensive Obstructions. Prominent buildings and similar extensive obstructions should be lighted in accordance with the following specifications. In the event the individual objects of a group of obstructions are approximately the same overall height above ground, or water if so situated, and are be considered an extensive obstruction and so lighted. located not more than 150 feet apart, the group of obstructions may
(1) When the particular obstruction is not more than 150 feet in overall height above ground, or water if so situated;
(a) If the obstruction is not more than 150 feet in either horizontal dimension, there should be installed at the major axis of the obstruction at least one light, approximately the highest point or edge at each end of consisting of a lamp of at least 100 watts, enclosed in an aviation red obstruction light globe. These lights should be positioned so as to insure unobstructed visibility of them from aircraft at any normal angle of approach, and to indicate the general extent of the as to make this manner of lighting impracticable, there obstruction; or, if the shape of the obstruction is such may be installed two such lights at the approximate center of the highest point or edge of the obstruction. Both lights should burn simultaneously and be so positioned as to insure unobstructed visibility of at least one of the lights from aircraft at any normal angle of approach.
If the obstruction is more than 150 feet in one horizontal dimension, but not more than 150 feet in the other, there should be installed at least one light, consisting of a lamp of at least 100 watts enclosed in an aviation red obstruction light globe, for each 150 feet, or fraction thereof, of the overall length of the major axis of the obstruction. At least one of these top lights should be installed on the highest point or edge of each end of the obstruction, with the additional lights as required spaced at approximately equal intervals not exceeding 150 feet, on the highest points or edge between the end lights in a manner to indicate the extent of the obstruction and to insure unobstructed visibility of the lights from aircraft at any normal angle of approach. If there are two or more edges of the same height on such an obstruction located near a be lighted. landing area, the edge nearest the landing area should Page 32 Chap. 6 Par. 19
1 Jan 72 AC 70/7460-1A
(c) If the obstruction is more than 150 feet in both horizontal dimensions, there should be installed at least one light, consisting of a lamp of at least 100 watts enclosed in an aviation red obstruction light globe, on the highest point of each corner of the obstruction. In addition, there should be installed at least one similar light for each 150 feet, or fraction thereof, when the distance between the corner lights exceeds 150 feet. These additional lights should be installed at approximately equal intervals, at the highest points along the outer edges of the obstruction, between the corner lights in a manner to indicate the general extent and definition of the obstruction and to insure unobstructed visibility of the lights from aircraft at any normal angle of approach, In the event there are one or more points within the outer edges of the obstruction, the uppermost parts of which are higher than the highest level of the lights prescribed above, at least one similar light should be displayed from the top of each such point.
(2) When the particular obstruction is more than 150 feet in overall height above ground, or water if so situated:
(a) Top lights should be installed on the obstruction in the manner set forth in the applicable provisions of Section d(1) above.
Intermediate lights, each consisting of a lamp of at least 100 watts enclosed in an aviation red obstruction light globe, should be provided for each 150 feet, or fraction thereof, the obstruction exceeds 150 feet in overall height above ground, or water if so situated.
The position of these intermediate lights on the vertical plane should be as close to the equidistant levels between the top lights and the ground level as the particular shape and type of obstruction will permit. One such light should be installed at each outside corner of the obstruction at each level and also one such light should be installed at equal intervals on the horizontal plane on each outer surface at each level between adjacent corner lights, for each 150 feet, or fraction thereof, when the overall horizontal distance between such adjacent corner lights exceeds 150 feet.
Chap. 6 Par. 19 Page 33
AC 70/7460-1A 1 Jan 72 In lieu of installing the obstruction lights on the prescribed in Section 19a. and lighted in accordance with the specifications greater than the overall height of the obstruction may be installed on or adjacent to the obstruction obstruction, a pole or poles of a height slightly It is important that those towers, poles, or similar obstruction. dicate the general definition and extent of the structures be installed in such a manner as to in-
(c) ed in Section 18a. Section d(1) and d(2) above, should be replaced with one necessary to provide adequate protection for aircraft, or more flashing 300mm electric code beacons as describ- the top lights on each obstruction as required under In the event early or special warning is considered lights would be impracticable or inadequate, flashing or Where obstructions are extensive as in the case of a line rotating hazard beacons may be used as an alternate to of trees or hills, and the use of the fixed obstruction of lights. of the type described in Chapter 5 of this circular. vided at least three beacons are placed on any one side or edge of the extensive obstruction to indicate a line obstruction at intervals not exceeding 3,000 feet, pro- the fixed obstruction lights. Such beacons should be located on the highest points or edges of the extended The flashing or rotating beacons should be States Coast Guard to avoid interference with marine navigation. bridge structure is over navigable water, approval of the lighting Bridges. accordance with the following specifications. However, where the installation must be obtained from the Commandant of the United The superstructure of a bridge should be lighted in approach. least one of the lights from aircraft at any normal angle of The two lights should burn simultaneously and should be positioned so as to insure unobstructed visibility of at watts, enclosed in aviation red obstruction light globes. two lights, each light consisting of a lamp of at least 100 center of the highest point of the superstructure at least When the bridge Superstructure is not more than 150 feet in overall length: There should be installed at the approximate Page 34 Chap. 6 Par. 19
1 Jan 72 AC 70/7460-1A
(2) When the bridge superstructure is more than 150 feet in overall length:
(a) There should be installed for each 150 feet, or fraction thereof, of the overall length of the bridge superstructure one or more lights, each light consisting of a lamp of at least 100 watts, enclosed in aviation red obstruction light globes. These lights should be installed on the highest points of the superstructure at approximately equal intervals not exceeding 150 feet in a manner to indicate the general definition and extent of the obstruction, and to insure unobstructed visibility of the lights from aircraft at any normal angle of approach. The distance not exceeding 600 feet when the particular bridge is located more than 15,000 feet from the reference point of any landing area.
Where the bridge superstructure exceeds 150 feet in overall length and the use of the above described obstruction lights would be impracticable or inadequate, flashing or rotating hazard beacons should be used as an alternate to the fixed obstruction lights. Such beacons should be located on the highest points or edge of the bridge superstructure at intervals not exceeding 3,000 feet, provided at least three beacons are installed to indicate the extent of the obstruction. The flashing or rotating beacons should be of the type described in Chapter 5 of this circular.
e. Water Towers, Grain Elevators, Gas Holders, and Similar Obstructions.
when the particular obstruction is: should be lighted in accordance with the following specifications, Water towers, grain elevators, gas holders, and similar obstructions Not more than 150 feet in overall height above ground, or water if so situated:
(a) At the top apply 18b(1).
(2) More than 150 feet but not more than 300 feet:
(a) At the top apply 18a(1).
(Б) At the approximate midpoint of the overall height (as equidistant between the ground and the top of the structure as the shape of the obstruction will permit) apply 185(2).
Chap. 6 Par. 19 Page 35