Part VI - General Operating and Flight Rules

Canadian Aviation Regulations (CARs) 2015-2

Standard 621 - Obstruction Marking and Lighting

(amended 2011/12/31: previous version)

Content last revised: 2012/06/01

CHAPTER 1   INTRODUCTION

1.1 Definitions 

In this Standard:

“appurtenance” – (Note: this term is defined as "projection" in the CARs) means that part of any vertical mast, pole or other appendage added to a building, structure or object that protrudes above the top of the building, structure or object; (accessoire)

“aviation colours” – for lighting, the colours as defined in the ICAO Annex 14; (couleurs)

“beam spread” – means the angle between the two directions in the vertical or horizontal plane in which the intensity is equal to 50 percent of the minimum specified peak beam effective intensity; (angle d’ouverture du faisceau)

“catenary” – means the curved span of overhead wires hung freely between two supporting structures, normally with regard to exceptionally long elevated spans over canyons, rivers and deep valleys; (caténaire)

“effective intensity” – means the effective intensity of a flashing light is equal to the intensity of a steady-burning (fixed) light of the same color which produces the same visual range under identical conditions of observation; (intensité efficace).

“fixed light” – means a light having constant luminous intensity when observed from a fixed point; (feu fixe)

“lighting” – means any light displayed on an obstruction as a means of indicating the presence of the obstruction to pilots; (éclairage)

“lighting terms” – refer Figure 1-1 (unités photométriques)

  • (a) Lumen - International System unit of luminous flux equal to the amount of light given out through a solid angle of 1 steradian by a point source of 1 candela intensity radiating uniformly in all directions. The unit expresses the quantity of light output per second. lumen)
  • (b) Candela - International System unit of luminous intensity of light emitted from a light source; equal to 1/60 of the luminous intensity per square centimetre of a blackbody radiating at the temperature of solidification of platinum (2,046°K). A luminous intensity of one candela is one lumen per steradian (solid angle). The unit expresses the intensity of light within an incremental segment of the beam. (candela)
  • (c) Lux - International System unit of illumination, equal to one lumen per square metre (lm/m2). The unit expresses the amount of light falling on the surface area. (lux)

“marker” – means an object displayed on an obstruction during daytime as a means of indicating the presence of relatively invisible obstructions such as power lines; (balise)

“marking” – means a symbol, group of symbols, or markers that are displayed on the surface of an obstruction and intended to reduce hazards to aircraft by indicating the presence of the obstruction by day; (balisage)

“meteorological visibility” – means the greatest distance, expressed in statute miles, that selected objects (visibility markers) or lights of moderate intensity at night (25 candela) can be seen and identified under specific conditions of observation; (visibilité météorologique)

“painting” – means a marking applied to the surface of an obstruction and intended to identify the presence of the obstruction by day; (marque de peinture)

“vertical aiming angle” – means the angle formed between the horizontal and a line through the centre of the vertical beam spread. (calage en site)

“wind turbine” means a structure intended for the production of electrical power; comprising a support mast on which is installed a nacelle containing a generator unit and which supports rotor blades that are caused to rotate by the wind. The total height of the obstruction is the height of the nacelle, above ground level (AGL), plus the length of one of the blades held in a vertical position. (éolienne)

“wind farm” means a grouping of 3 or more wind turbines. (parc d’éoliennes)

“wind farm indicators” means light units installed with specified spacing on selected wind turbines and serving to indicate the location of a wind farm to pilots. (indicateurs de parc d’éoliennes)

1.2 Notification Responsibilities

(1) A person planning to erect or modify an obstruction, namely a building, structure or object, including a moored balloon or kite, either permanently or temporarily, contact the appropriate regional Transport Canada Civil Aviation office, as specified in Appendix A , at least 90 days prior to erection and provide the information on the planned obstruction, using the Aeronautical assessment form for obstruction marking and lighting as shown in Appendix C:

(2) If it appears that planned construction might create an obstruction to air navigation in the vicinity of a Department of National Defence (DND) aerodrome, the person having responsibility or control over the construction advise the appropriate DND authorities.

Information Note:  Any person planning to erect an obstruction should also provide information to Nav Canada, using the “Land Use Proposal Submission Form” (« Projet d'utilisation particulière d'un terrain ») which is available from the appropriate Transport Canada regional office. (See Appendix A)

Information Note:  Where possible, for objects such as broadcast antennae and wind farms, a sign identifying the owner of the object and providing contact information should be installed at the entrance gate or any other place as appropriate.

CHAPTER 2   GENERAL

2.1 Purpose of Marking and Lighting Requirements

Information Note:  The application of the marking and lighting requirements specified in this Standard and the approval of equivalent requirements is to ensure that an obstruction to air navigation remains visible at a range sufficient to permit a pilot in VMC conditions to take appropriate action in order to avoid the obstruction, by not less than 300 m vertically within a horizontal radius of 600 m from the obstruction. In other words, the purpose of obstruction marking and lighting standards is to provide an effective means of indicating the presence of objects likely to present a hazard to aviation safety. Equivalent lighting and marking requirements can be approved depending on terrain features, weather patterns, geographic location, and in the case of wind turbines, depending on the number of structures and overall layout of design, in accordance with the criteria and procedures outlined in sections 2.2 and 2.3. below.

2.2 Shielding

(1) The principle of shielding is applied in a way that a dominant permanent building, structure or object which is marked or lighted, or both, obviates the need for marking or lighting other buildings, structures or objects in the immediate surrounding area, which might otherwise be treated as individual obstructions.

(2) More specifically, the principle of shielding is applied if the marking or lighting, or both, of a dominant permanent building, structure or object is assessed by the Transport Canada regional office as providing sufficient warning to aircraft that, in avoiding the dominant obstruction, they will also avoid the unmarked or unlighted obstructions in the immediate surrounding area without risk of collision.

(3) Where two similar objects of equal height are situated adjacent to each other, as shown in Figure 2-2, one of the two objects may be considered as shielded, provided the separations listed in Table 2-1 are not exceeded.

Table 2-1:  Separation between Shielded Objects

Height of Objects AGL (metres) Maximum Separation (metres)

30 to 75

15

76 to 122

23

123 to 198

30

199 to 290

45

291 and higher

60

(4) A narrow obstruction may be considered as shielded when it is situated with respect to a large obstruction so that an aircraft, whose flight path would avoid the large obstruction would, as a result, also avoid the narrow one.

(5) Adjacent Catenaries

  1. (a) A catenary across a recognized VFR route does not require marking or lighting where it is shielded by a larger object such as a bridge or a higher catenary.
  2. (b) A catenary segment may be considered as shielded when it is situated within 600 m of the marked catenary of the dominant obstruction so that it remains below a sloping down surface at a gradient of 5% projected from the marked catenary. Refer to Figure 2-1.
  3. (c) If the second catenary is above the gradient, this span may not be considered as shielded and is marked or lighted, or both, in accordance with this Standard.

(6) Complex Objects

  1. (a) Where it is not possible to apply a uniform standard to a cluster of objects such as industrial plants, oil refineries, thermal generating stations, and similar structures, they shall be assessed by the Transport Canada regional office on an individual basis to determine whether or not to treat them as hazards to aviation safety or as an extended obstruction, taking into account the objects' location and height.
  2. (b) When treated as an extended obstruction, sufficient marking or lighting, or both, are provided to ensure that the extent of the cluster is defined and visual warning is provided from any angle of aircraft approach.

2.3 Lighting Equipment

(1) Conformance

Information Note:  As a basis of ensuring procurement of equipment meets the requirements of this Standard, the person having responsibility or control over the obstruction should obtain an attestation of conformance through an established 3rd Party testing laboratory.

(2) Combined Light Units

Information Note:  The requirements specified in this Standard are written with respect to the performance of obstruction lighting, without consideration of how they are actually designed. Manufacturers may supply light sources contained within a single fitting. For example, a combined CL-864 red flashing beacon with a CL-865 white flashing light, as may be used for a dual medium intensity, configuration “E” installation.

2.4 Environmental Evaluation

Information Note:  The person having responsibility or control over an obstruction may be required to file an environmental evaluation with the appropriate authority having jurisdiction when seeking authorization for the use of the high intensity flashing white lighting system on structures located in residential neighbourhoods, as defined by the applicable zoning law.

CHAPTER 3   MARKING AND MARKERS

3.1 Scope

Chapter 3 governs marking requirements for obstructions to air navigation in order to make them conspicuous to pilots during daylight.

3.2 Paint Standards

Where alternate sections of aviation orange and white, referred herein as "orange" and "white" paint markings, are required under this Standard to be displayed on a building, structure or object, the colours of paint markings shall be in accordance with United States Federal Standard FED–STD–595B, for colours identified as:

  1. (a) orange, number 12197; and
  2. (b) white, number 17875.

3.3 Surfaces Not Requiring Paint

(1) Except as otherwise provided for in Chapter 3, ladders, decks, and walkways of steel towers and similar structures are not to be painted, if a painted surface presents a potential hazard to maintenance personnel.

(2) Subject to subsection (3), paint may be omitted from precision or critical surfaces, if it would have an adverse effect on the transmission or radiation characteristics of a signal.

(3) Where markings are omitted under subsection (1) or (2), the overall marking effect of the structure shall not be reduced to the point of compromising the visibility criteria of section 2.1.

3.4 Use of Plastic Wrapping

In the case of poles, where the use of paint is impractical, a wrapping of plastic or other weather resistant material, in the required colours and dimensions, may be applied instead of painting provided that the colour of the wrapping corresponds as close as possible to that required for a painted marking.

3.5 Paint Patterns

Information Note:  The following patterns of painting are dependent upon the size and shape of the structure.

(1) Solid Pattern

A structure is coloured solid orange, if the structure has both horizontal and vertical dimensions not exceeding 3.2 m.

(2) Checkerboard Pattern

  1. (a) Subject to paragraph (c), alternating rectangles of aviation orange and white are displayed on the following types of structure
    1. (i) storage tanks for water, gas, grain, and similar tanks,
    2. (ii) buildings,
    3. (iii) structures that both:
      1. (A) appear broad from a side view, that are 3.2 m or more across horizontally, and
      2. (B) have a horizontal dimension that is equal to or greater than the vertical dimension.
  2. (b) Checkerboard patterns have the following characteristics [refer to Figure 3-1]:
    1. (i) for structures having horizontal and vertical dimensions, both greater than 3.2 m, the sides of the checkerboard pattern measure not less than 1.5 m nor more than 6 m,
    2. (ii) for structures having horizontal or vertical dimensions, both less than 4.5 m, the sides of the checkerboard pattern may be less than 1.5 m, but not less than 1 m,
    3. (iii) the rectangles of the pattern are as nearly square as possible, and
    4. (iv) corners are coloured orange.
  3. (c) The following exceptions apply to the marking requirements set out in this subsection:
    1. (i) storage tanks not suitable for a checkerboard pattern are coloured with alternating bands of aviation orange and white or a limited checkerboard pattern applied to the upper one-third of the structure, and
    2. (ii) the skeletal framework of certain water, gas, and grain storage tanks may be excluded, as a result of a risk evaluation, from the checkerboard pattern, where the main structure of the storage tank is large enough that its checkerboard pattern adequately suits the purpose of day marking.

(3) Colour Bands

  1. (a) Subject to subsection (4), alternate bands of orange and white are displayed on the following types of structure:
    1. (i) communications towers and supporting structures of overhead transmission lines,
    2. (ii) poles,
    3. (iii) chimneys,
    4. (iv) skeletal framework of storage tanks and similar structures,
    5. (v) wind turbine towers and rotor blades, including the nacelle or generator housing,
    6. (vi) cables, conduits, and materials attached to the face of a tower, whether at time of construction or when later added to the structure, and
    7. (vii) structures that appear narrow from a side view, that are 3.2 m or more across horizontally, and the horizontal dimension is less than the vertical dimension.
  2. (b) Bands applied to structures of any height in excess of 3.2 m [Refer to Figure 3-4]:
    1. (i) are approximately equal in width and to a tolerance of ± 10 percent,
    2. (ii) are not more than 30 m wide,
    3. (iii) are coloured orange for the top and bottom bands,
    4. (iv) have an odd number of bands on the structure, and
    5. (v) are in accordance with Table 3-1, except that for each additional 60 m or fraction thereof, one (1) additional orange and one (1) additional white band are added.

Table 3-1:  Structure Height to Number of Bands Requirement

Structure height (AGL)

 

Greater than
(metres)
Not exceeding
(metres)
Number of Bands

0

3.2

solid

3.2

210

7

210

270

9

270

330

11

330

390

13

390

450

15

450

510

17

510

570

19

570

630

21

(4) Structures With a Cover or Roof

If a structure referred to in subsection (3) has a cover or roof whose profile in the line of sight of approaching aircraft is less than 1.5 m, the highest orange band is continued to cover the entire top of the structure. It is acceptable to have the roof made of a solid orange provided that the structure below has a checkerboard pattern.

(5) Skeletal Structures Atop Buildings

Where a flagpole, skeletal structure, or similar object is erected on top of a building:

  1. (a) the combined height of the object and the building determines whether marking is required; however, only the height of the object determines the width of the colour bands; and
  2. (b) if the building is required to have a checkerboard pattern of marking, the object and its height are considered separately for banding determination.

(6) Appurtenances

If a tower or similar skeletal structure is required to have banded marking and it also has an appurtenance of more than 12 m, then the combined height of the appurtenance plus that of the main structure determine the width of the banding.

(7) Partial Marking 

If marking is required for only a portion of a structure because of shielding by other objects or terrain:

  1. (a) the width of the bands is determined by the overall height of the structure;
  2. (b) a minimum of three bands are displayed on the upper portion of the structure; and
  3. (c) in the case of cylindrical storage tanks as shown in Figure 3-2, the checkerboard marking may be applied to the top ½ to 2/3 of the tank.

(8) Teardrop Pattern

Spherical water storage tanks with a single circular standpipe support may be marked in a teardrop-striped pattern having the following characteristics:

  1. (a) alternate stripes of aviation orange and white are displayed on the tank, as shown in Figure 3-2;
  2. (b) the stripes extend from the top centre of the tank to its supporting standpipe; and
  3. (c) the width of the stripes are nearly as equal as possible and the width at the greatest girth of the tank is not to be less than 1.5 m nor more than 6 m.

(9) Community Names

If it is desirable to paint the name of the community on the side of a tank, the marking pattern may be broken for a height of not more than 1.0 m to serve this purpose.

3.6 Flag Markers

(1) Application

One or several flags may be used as markers instead of paint to indicate the presence of certain structures or objects when it is technically impractical to use spherical markers or painting.

Information Note:  Some examples of structures or objects where flags may be used are temporary construction equipment, cranes, derricks, oil and other drilling rigs.

(2) Characteristics

Flags used as markers under subsection (1) have the following characteristics:

  1. (a) Minimum Size - each side of a flag is at least 0.6 m in length;
  2. (b) Colour Patterns - they are coloured as follows:
    1. (i) if solid, the colour is orange,
    2. (ii) if orange and white colours are used, two triangular sections, one aviation orange and the other white, are arranged to form a rectangle, or
    3. (iii) a checkerboard pattern of aviation orange and white squares of 0.3 m to a side, is used if the flags are 0.9 m or larger;
  3. (c) Shape - they are rectangular in shape and have stiffeners to keep it from drooping in calm wind; and
  4. (d) Manner of Display - they are displayed as follows:
    1. (i) around, on top, or along the highest edge of the obstruction,
    2. (ii) when used to mark extensive or closely grouped obstructions, the flags are displayed approximately 15 m apart, and
    3. (iii) the flag stakes are to be of such strength and height that they are able to support the flags above all surrounding ground, structures, or objects of natural growth, as the case may be.

3.7 Omission of Marking with Use of Lighting

A high or medium intensity white flashing lighting system may be used in place of marking if the following conditions are met:

  1. (a) the lighting system is operated 24 hours a day; and
  2. (b) in the case of a medium intensity lighting system, the system:
    1. (i) is operated 24 hours per day, and
    2. (ii) the structure on which it is used is 150 m AGL or less.

CHAPTER 4   LIGHTING, GENERAL

4.1 Scope

Chapter 4 governs lighting requirements for obstructions to air navigation in order to make them conspicuous to pilots during night time, except as otherwise provided for in this Standard. It also governs the marking requirements of catenary wires, catenary support structures, moored balloons and kites, for daytime.

Information Note:  Lighting is used to warn pilots of a potential collision during night time operations. If the lighting is of sufficient intensity, it may also serve to give warning during daytime operations and may be approved, by way of a risk evaluation, in lieu of other means of day marking. Criteria for lighting structures, as a result of a risk evaluation, can vary depending on terrain features, weather patterns, and geographic location.

4.2 Lighting Systems

(1) Configurations

Obstruction lighting is displayed on a building, structure or object in one of six configurations, as shown in name+ 4-1 and listed in Table 4-2.

Information Note:  The following is a listing of light units required under this Standard. Chapter 13 provides detailed characteristics of these light units. Appendix B contains the governing electrotechnical requirements and quality assurance testing.

Table 4-1: Light Units

Type Intensity Colour Signal Flash Rate (fpm)

CL-810

Low

red

fixed

n/a

CL-864

Medium

red

flashing

20-40

CL-865

Medium

white

flashing

40

CL-866, Catenary

Medium

white

flashing

60

CL-885, Catenary

Medium

red

flashing

60

CL-856

High

white

flashing

40

CL-857, Catenary

High

white

flashing

60

Note 1:  In certain cases, some of these lights are supplied as a combined unit (e.g. CL–864/CL–865)

Note 2:  fpm = flashes per minute

Table 4-2:  Lighting Configurations

Configuration Lighting

A

CL-810 low and CL-864 medium intensity red lighting system

B

CL-856 white high intensity (without appurtenance lighting)

C

CL-856 white high intensity (with CL-865 appurtenance lighting)

D

CL-866 white medium intensity

E

Dual CL-810/CL-864 red with CL-865 white medium intensity lighting

F

Dual CL-810/CL-864 red with CL-856 white high intensity lighting

(2) Red Lighting Systems

A red obstruction lighting system consists of CL-810 low intensity steady burning aviation red lights and CL-864 medium intensity red flashing aviation beacons.

(3) CL-865 Medium Intensity White Flashing Lighting Systems

  1. (a) A medium intensity white flashing lighting system consists of CL-865 medium intensity flashing white lights used during day/twilight with automatically selected reduced intensity for night time operation.
  2. (b) When the system is used on a building, structure or object 150 m AGL or less in height, the marking requirements may be omitted.

Information Note 1:  No exemption applies from the requirement to display markings on a building, structure or object exceeding 150 m AGL that has a CL-865 medium intensity white flashing lighting system.

Information Note 2:  This lighting system is not normally recommended on buildings, structures or objects 60 m AGL or less.

(4) High Intensity White Flashing Lighting Systems

  1. (a) A high intensity white flashing lighting system consists of CL-856 and CL-857 high intensity flashing white lights used during daytime with automatically selected reduced intensities for twilight and night time operations.
  2. (b) When the system is in use, the markings and the other lights required to be displayed on the building, structure or object may be omitted.

Information Note:  This lighting system should not be used on buildings, structures or objects 150 m AGL or less, unless a risk evaluation shows otherwise.

(5) Dual Lighting Installation

  1. (a) A dual lighting system consists of red lights for night time use and high or medium intensity flashing white lights for daytime and twilight use.
  2. (b) When a dual lighting system incorporates medium flashing intensity lights on a building, structure or object 150 m or less in height, or high intensity flashing white lights on a building, structure or object of any height, the marking and the other lighting requirements may be omitted.

Information Note:  When a building, structure or object is located in an urban area where there are numerous other white lights (e.g., streetlights, etc.), red obstruction lights with painting or a medium intensity dual system is recommended.

4.3 Floodlighting

  1. (1) A chimney, church steeple or similar obstruction not exceeding 150 m in height, may be floodlighted by three or more fixed search light projectors installed at equidistant points around the base of the obstruction.
  2. (2) Where floodlighting is used for an obstruction referred to in subsection (1), the top 1/3 of the structure shall be provided with at least 30 lux of illumination as directed from the object horizontally to an approaching pilot, assuming diffuse reflection from the object.

4.4 Obstruction Lights During Construction

  1. (1) As the height of a building, structure or object under construction progressively exceeds each level at which permanent obstruction lights would be required, two or more temporary medium intensity white flashing lights are installed at that level.
  2. (2) Temporary lighting required under subsection (1) is operated 24 hours a day until all permanent lights required under this Standard are in operation.
  3. (3) If practical, permanent obstruction lighting required under this Standard shall be installed and operated at each level as construction progresses.
  4. (4) The lights shall be positioned to ensure that a pilot has an unobstructed view from any angle of approach of at least one light at each level.

4.5 Temporary Construction Equipment Lighting

Information Note:  Since there is such a variance in construction cranes, derricks, oil and other drilling rigs, each case should be assessed individually. However, in principle, lights should be installed according to the standards given herein, as they would apply to permanent structures.

4.6 Groups of Obstructions

  1. (1) When individual buildings, structures or objects within a group of obstructions are not the same height and are spaced more than 45 m apart, the prominent building, structure or object within the group is lighted in accordance with the standards for individual obstructions of a corresponding height.
  2. (2) If an outer building or structure is shorter than the prominent one, it is lighted in accordance with the requirements for individual obstructions of a corresponding height.
  3. (3) Light units required under this section are placed to ensure that the light is visible to a pilot approaching from any direction.
  4. (4) In addition to the requirement set out in subsection (3), at least one flashing beacon is installed at the top of a prominent centre obstruction or on a special tower located near the centre of the group.
  5. (5) If there is no prominent centre obstruction, a risk evaluation shall be performed to assess the location of the applicable beacons.

4.7 Monitoring of Obstruction Lights

  1. (1) An obstruction lighting system required under Chapter 4 is monitored by visual or automatic means.
  2. (2) On a system without automatic monitoring, the obstruction lighting is visually inspected in all operating intensities at least once every 24 hours.
  3. (3) If the lighting system of a building, structure or object is not readily accessible for visual observation, a properly maintained automatic monitor is used.
  4. (4) The monitor referred to in subsection (3) is designed to register the malfunction of any light on the obstruction regardless of its position or colour.
  5. (5) When using a remote monitoring device, the communication status of the device and operational status of the lighting system is confirmed at least once every 24 hours.
  6. (6) The monitor display is located in an area occupied by responsible personnel where the status of the lighting can be noted at least once every 24 hours.
  7. (7) The owner or operator of the obstruction lighting system advises NAV CANADA, as soon as possible, of any obstruction lighting failures so that an appropriate NOTAM action can be initiated.

4.8 Glare from Flashing Obstruction Lights

  1. (1) Where obstruction lighting is likely to distract operators of aircraft, railway trains, surface vessels, and other vehicles, or if the lighting is in a congested residential area, a suitable shield is installed on the appropriate lights to minimize the glare effects of the light.
  2. (2) The application of such shielding shall not diminish the required performance of the light as specified in Chapter 13 of this Standard for obstruction identification to pilots.
  3. (3) Shielding applied to the exterior of the light unit is suitable for environmental conditions such as snow, ice and frost cover, so that the light output is not degraded from that required by this Standard.
  4. (4) In the proximity of navigable waterways or along coastal regions, the installation of an obstruction lighting system is coordinated with marine authorities by the owner or operator of the obstruction in order to avoid interference with marine navigation.

4.9 Placement Factors

  1. (1) The height of a building, structure or object above ground (AGL) is used to determine the number of light levels required to be installed as part of a lighting system.
  2. (2) The height of light levels required to be installed may be adjusted slightly, but not to exceed 3 m, when necessary to accommodate guy wires and personnel who replace or repair light fixtures.
  3. (3) Except for catenary support structures, the following factors are considered when determining the placement of obstruction lights on a building, structure or object:
    1. (a) for a red obstruction lighting system or a medium intensity white flashing lighting system, the overall height of the structure including all appurtenances such as rods, antennae, obstruction lights and similar objects, determine the number of light levels;
    2. (b) for a high intensity white flashing lighting system,
      1. (i) the overall height of the main structure excluding all appurtenances is used to determine the number of light levels, and
      2. (ii) if required, a CL-865 medium intensity flashing light is displayed on the highest portion of any antenna or other appurtenance supported by the main structure; and
    3. (c) for a dual obstruction lighting system, the determination of the number of light levels is in conformity with the pertinent requirements for white and red lighting systems.
  4. (4) The elevation of the tops of adjacent buildings or structures in congested areas is used as the equivalent of ground level to determine the proper number of light levels required.
  5. (5) If an adjacent building, structure or object shields any light, horizontal placement of the lights is adjusted or additional lights are mounted on that object to retain or contribute to the definition of the obstruction.

4.10 Ice Protectors

  1. (1) Where icing is likely to occur, metal grates or similar protective means are installed directly over each light unit required under this Standard to be installed on a building structure or object to prevent falling ice or accumulations from damaging the light units.
  2. (2) The protective means are of a design and manner of placement such that the required photometric output of the fixtures is not affected.

CHAPTER 5   RED OBSTRUCTION LIGHTING SYSTEM, CONFIGURATION “A”

5.1 Scope

Chapter 5 governs obstruction lighting that uses a configuration “A” lighting system.

5.2 System Requirements

(1) General

  1. (a) A configuration “A” red obstruction lighting system consists of one or several, as required under Chapter 5, CL-864 red flashing beacons or CL-810 steady burning red lights, or a combination thereof.
  2. (b) When red lighting alone is used for night protection, no exemption to markings required under this Standard is allowed.

Information Note:  The CL-810 comes in two forms; a single unit [one lamp and one globe] and a double unit [two lamps and two globes].

(2) Double Obstruction Light Units

Subject to subsection (3), when used as a top light or in areas or locations where the failure of a single unit could cause an obstruction to be totally unlighted, double unit CL-810 lights are installed at each end of a row of single unit obstruction lights, and more specifically as follows:

  1. (a) Top Level on a structure, building or object 45 m AGL or less, one or more double unit lights operating simultaneously are installed at the highest point;
  2. (b) Intermediate levels,
    1. (i) double unit lights are installed when a malfunction of a single unit light could create an unsafe condition and in remote areas where maintenance cannot be performed within a reasonable time, and
    2. (ii) both lamps of the double unit operate simultaneously or a transfer relay is used to switch to the inactive lamp should the active lamp fail; and
  3. (c) Lowest Level at the lowest level of a building, structure or object,
    1. (i) light units may be installed at a higher elevation than standard if the surrounding terrain, trees or any adjacent buildings would obscure the lights, or
    2. (ii) in certain exceptional instances, as determined by a risk evaluation, the lighting otherwise required for the lowest level may be omitted.

(3) Single CL-810 Obstruction Light Units

Where more than one obstruction light is required either vertically or horizontally, or where maintenance can be accomplished within a reasonable period of time, single unit CL-810 lights may be used as follows:

  1. (a) Top Level atop structures such as airport ILS buildings and long horizontal structures such as perimeter fences and building roof outlines; or
  2. (b) Intermediate Level at intermediate levels on skeletal or solid structures when more than one level of lights is required to be installed and there are two or more single units per level.

(4) Flashing Display

When one or more levels of lights are comprised of CL-864 flashing beacons, the lights shall flash simultaneously.

(5) Equivalent Method of Displaying Obstruction Lights

Provided that approval is obtained following the result of a risk evaluation, lights may be placed on poles equal to the height of the building, structure or object required to be lighted, and may be installed on or adjacent to such building, structure or object.

5.3 Radio and Television Towers and Similar Skeletal Structures

The following requirements apply to radio and television towers, supporting structures for overhead transmission lines, and similar structures. Refer to Figures 5-1 and 5-2.

(1) On the topmost part of a structure:

  1. (a) 45 m AGL or less, two or more steady burning lights are installed; or
  2. (b) exceeding 45 m AGL, at least one red flashing beacon is installed.

(2) On the intermediate levels of a structure:

  1. (a) the number of levels of lights is in accordance with Figures 5-1;
  2. (b) the number of lights at each level is determined by the shape and height of the structure;
  3. (c) the lights are installed so as to provide an unobstructed view of at least one light by a pilot from any angle of approach;
  4. (d) where CL-810 steady burning red lights are installed on:
    1. (i) a structure 105 m AGL or less, two or more steady burning red lights are installed on diagonally or diametrically opposite positions, and
    2. (ii) a triangular shaped structure 105 m AGL or less:
      1. (A) two red light units, single or double, are installed, provided that at least one can be viewed unobstructed by a pilot from any angle of approach, or
      2. (B) where the requirement specified in clause (A) is impractical, three red light units are installed, one on each apex of the triangular cross-section, or
    3. (iii) a structure exceeding 105 m AGL, a steady burning red light is installed on each outside corner at each level; and
  5. (e) where a CL-864 flashing red beacon is used on a structure exceeding 105 m AGL, the red flashing beacon is properly installed within the structure, except that if the structural members impair the viewing of the beacon, two flashing red beacons are installed on the outside of diagonally or diametrically opposite positions at each level.

(3) Appurtenances

Where a building, structure or object required to be lighted includes an appurtenance such as a rod, antenna, or similar extension, a topmost light is installed above the main part of the building, structure or object in accordance with the provisions of this subsection.

  1. (a) Where the appurtenance is 12 m or less in height and:
    1. (i) is incapable of supporting a red flashing beacon, the beacon may be placed at the base of the appurtenance, or
    2. (ii) if the mounting location does not allow unobstructed viewing of the beacon by a pilot from any angle of approach, additional beacons are added.
  2. (b) Where the appurtenance exceeds 12 m in height and:
    1. (i) is incapable of supporting a red flashing beacon, a supporting mast with one or more beacons is installed adjacent to the appurtenance, and
    2. (ii) the adjacent installation of (i) does not exceed the height of the appurtenance and is within 12 m of the tip of the appurtenance to allow the pilot an unobstructed view of at least one beacon, from any angle of approach.

5.4 Chimneys, Flare Stacks and Similar Solid Structures

(1) Lighting Levels and Location

  1. (a) CL-810 and CL-864 obstruction lights used on a chimney, flare stack or similar solid structure are installed in accordance with Figures 5-1.
  2. (b) The topmost lights may be located up to 6 m below the top of the structure to avoid the obscuring effect of emissions.

(2) Number of Light Units per Level

Subject to subsection (3), the number of lights to be installed at the top and at each level of a chimney, flare stack or similar solid structure depends on the diameter of the structure and is in accordance with Table 5-1.

Table 5-1:  Number of lights

Diameter Number of Lights at top and per level

6 m or less

3

6 m to 30 m

4

30 m to 60 m

6

more than 60 m

8

(3) Hyperbolic Cooling Towers

Where any cooling tower of a nuclear generating station:

  1. (a) is 180 m in height or less AGL, intermediate light levels may be omitted; or
  2. (b) exceeds 180 m AGL in height, a second level of light units is installed approximately at the midpoint of the structure and in a vertical line with the top level of lights.

5.5 Prominent Buildings and Similar Extensive Obstructions

(1) Subject to subsection (4), individual obstructions having a similar height above ground and located not more than 45 m apart within a group of obstructions may be considered as an extensive obstruction for lighting purposes, in which case the group displays steady burning red lights to indicate the extent of the obstruction as specified in this section.

(2) On a structure 45 m or less in both horizontal dimensions, a CL-810 light is displayed:

  1. (a) on the highest point at each end of the major axis of the obstruction; or
  2. (b) in the centre of the highest point.

(3) Structures Exceeding 45 m in any Horizontal Dimension

  1. (a) On a structure exceeding 45 m in any horizontal dimension, CL-810 lights are displayed on:
  2. (i) the highest point at each end of the obstruction, and
  3. (ii) the highest points for each 45 m, or fraction thereof, for the overall length of the major axis.
  4. (b) If the minor axis of a structure exceeding 45 m in one of its horizontal dimensions is 45 m or less in length, the lights referred to in paragraph (a) may be installed as a row along the middle or along either side, as shown in Figure 5-3.
  5. (c) If a structure exceeding 45 m in any horizontal dimension is located near a landing area and two or more edges of the structure are of the same height, the edge nearest the landing area is lighted with CL-810 lights.

(4) Structures Exceeding 45 m AGL

  1. (a) Top Lights – CL-810 steady burning red lights are installed on the highest point at each end of a structure exceeding 45 m AGL in height.
  2. (b) At intermediate levels of the structure,
    1. (i) a CL-810 steady burning red light is displayed for each 45 m or fraction thereof,
    2. (ii) the vertical position of the intermediate lights is equidistant between the top lights and the ground level as the shape and type of obstruction will permit, and
    3. (iii) one CL-810 steady burning red light is displayed at each outside corner on each level with the remaining lights evenly spaced between the corner lights.

(5) Exceptions

Flashing red CL-864 beacons may be used instead of steady burning lights if early or special warning to pilots is necessary, provided that, in the case of an extensive obstruction:

  1. (a) they are displayed on the highest points of the obstruction, at intervals not exceeding 900 m; and
  2. (b) at least three beacons are displayed on one side of the obstruction to indicate a line of lights.

5.6 Bridges

(1) A bridge assessed through a risk evaluation as a likely hazard to aviation safety has CL-864 red flashing lighting, as shown in Figure 5-4.

(2) If the bridge referred to in subsection (1) is over navigable water, the obstruction lighting installer consults with the Coast Guard to avoid interference with signals to marine navigation.

5.7 Groups of Objects

(1) Of Different Height

  1. (a) A group of objects, except wind turbines, of varying heights is lighted in accordance with the requirements specified for individual obstructions of a corresponding height.
  2. (b) In addition, at least one medium intensity flashing white light is installed at the top of a prominent centre obstruction or on a special tower located near the centre of the group.

(2) Of Similar Height 

A group of objects of equal height is lighted in accordance with the requirements specified in section 5.5.

5.8 Characteristics of Lights

Lighting displayed on a bridge has the light characteristics specified in Chapter 13.

CHAPTER 6   MEDIUM INTENSITY WHITE FLASHING SYSTEM, CONFIGURATION “D”

6.1 Scope

Chapter 6 governs obstruction lighting that uses a configuration “D” lighting system.

6.2 Application

CL-865 medium intensity white flashing light units:

  1. (a) are used during daytime and twilight with automatically selected reduced intensity for night time operation;
  2. (b) where used on a building, structure or object 150 m AGL or less in height, may result in day marking otherwise required under Chapter 3 being omitted on the building, structure or object; and
  3. (c) where used on a building, structure or object greater than 150 m AGL, shall not result in any day marking required under Chapter 3 being omitted on the building, structure or object.

Information Note: CL-865 medium intensity white flashing light units should not be used:

(1) on a building, structure or object 60 m AGL or less in height;

(2) in populated urban areas due to their tendency to merge with background lighting in these areas at night and the cause of glare complaints; and

(3) on structures within 5 kilometres of an airport.

6.3 Characteristics

(1) Photometrics

The photometric output of a configuration “D” lighting system is in accordance with Table 13–2.

(2) Control

The lighting system is in accordance with Table 13-1 for day, twilight and night modes of operation.

6.4 Radio and Television Tower and Similar Skeletal Structures

(1) Subject to subsection (4), on a radio or television tower, or similar skeletal structure, the number of light levels to be installed depends on the height of the structure, including antennae and similar appurtenances, and is determined in accordance with Figure 6-1.

(2) Top Level

One or more light units are installed at the highest point of a skeletal structure to provide 360-degree coverage ensuring an unobstructed view.

(3) Intermediate Levels

At an intermediate level of a skeletal structure, two CL-865 beacons are mounted outside, at diagonally or diametrically opposite positions of the intermediate level.

(4) Lowest Level

At the lowest level of light units of a skeletal structure:

  1. (a) the light units may be installed at a higher elevation than that required under this section for the structure, if the surrounding terrain, trees, or any adjacent building would obscure the light units;
  2. (b) in circumstances determined by a risk evaluation, the light units may be omitted; and
  3. (c) CL-865 light units are not to be installed at a height of less than 60 m.

(5) Appurtenances

An appurtenance is lighted in accordance with the requirements specified in subsection 5.3(3), except as far as the use of the CL-865 light in place of CL-864 light is concerned.

6.5 Chimneys, Flare Stacks, and Similar Solid Structures

(1) Lighting Levels and Location

The number of levels of light units required to be installed on a chimney, a flare stack or similar solid structure is determined in accordance with Figure 6-1.

(2) Number of Light Units per Level

The number of light units required to be installed on each level of a solid structure referred to in subsection (1), is determined in accordance with Table 5-1.

6.6 Hyperbolic Cooling Towers

A hyperbolic cooling tower is lighted in accordance with the requirements specified in section 5.4.

6.7 Prominent Buildings and Similar Extensive Obstructions

(1) Application is that of section 5.7, except with the use of CL-865 medium intensity white flashing lights.

(2) Due to the glare factor, caution shall be used in the application of medium intensity white flashing lights.

6.8 Bridges

A bridge is lighted in accordance with the requirements specified in section 5.6.

CHAPTER 7   HIGH INTENSITY WHITE FLASHING SYSTEM, CONFIGURATION “B” and “C”

7.1 Scope 

Chapter 7 governs obstruction lighting that uses a configuration “B” and “C” lighting system.

7.2 Application

When a high intensity white flashing lighting system is operated 24 hours a day, the marking requirements and the other applicable lighting requirements for an obstruction may be omitted.

Information Note:  This lighting system is not recommended on structures 150 m AGL or less, unless a risk evaluation shows otherwise.

7.3 Characteristics

(1) Photometrics

The photometric output of a high intensity white flashing lighting system is in accordance with Table 13-2.

(2) Control

The lighting system is controlled in accordance with Table 13-1 for day, twilight and night modes of operation.

7.4 Installation

(1) Vertical Aiming

In order to avoid potential glare problems, the vertical aiming angle of a CL-856 light unit used in a high intensity white flashing system is as follows:

Location

  1. (a) the unit is adjusted to compensate for its height above ground, in accordance with Table 7-1; and

Table 7-1: Vertical Aiming of HI Light Units

Location of light unit AGL
(metres)
Beam angle adjustment
(degrees)

higher than 153 m

0

122 to 153 m

1

92 to 121 m

2

lower than 92 m

3

Terrain

  1. (b)
    1. (i) where terrain, nearby residential areas, or other situations dictate, the light beam of a light unit may be further elevated above the horizontal,
    2. (ii) the main beam of light unit located at the lowest level of a building, structure or object shall not strike the ground closer than 5 km from the building, structure or object,
    3. (iii) if additional adjustments are necessary, light units may be individually adjusted upward, in 1 degree increments, starting at the bottom of the building structure or object,
    4. (iv) excessive elevation, however, may reduce conspicuousness by raising the beam above a collision course flight path,
    5. (v) where the lighting system is installed on a building, structure or object located near a highway, waterway, or airport approach area, shielding or vertical or horizontal aiming adjustments, or both, shall be made as necessary to avoid causing glare, and
    6. (vi) adjustment of light units shall not derogate from the conspicuousness requirement set out in section 2.1 of this Standard.

(2) Relocation or Omission of Light Units

Where any light units are obstructed from view by a building, structure or object, including surrounding terrain and trees, the following actions may be taken:

Lowest Level 

  1. (a) in the case of the lowest level of lights:
    1. (i) the light units may be installed at a higher elevation than that required under Chapter 7, and
    2. (ii) in circumstances determined by a risk evaluation, the light units may be omitted; and

Two Adjacent Structures

  1. (b) in the case of adjacent buildings or structures:
    1. (i) if two buildings or structures are situated within 150 m of each other and their respective light units are installed at similar levels, the light units on the sides of the buildings or structures facing each other may be omitted provided that all lights on both structures flash simultaneously, except for adjacent catenary support structures,
    2. (ii) vertical placement of the lights to either or both structures’ intermediate levels is adjusted to place the lights on the same horizontal plane,
    3. (iii) where one building or structure is higher than the other, one or more complete levels of light units, as the case may be, is installed on that part of the higher building or structure that extends above the top of the lower structure, and
    4. (iv) if the structures are of such heights that their respective levels of lights cannot be placed in identical horizontal planes, the levels of light units are placed such that the centre of the horizontal beam patterns does not face toward the adjacent building or structure; and
    5. Information Note:  For example, based on subparagraph (iv) above, structures situated north and south of each other will have the light units on both structures installed on a northwest/southeast and northeast/southwest orientation.

Three or More Adjacent Structures

  1. (c) the treatment of a cluster of structures as an individual or a complex of structures is determined by way of a risk evaluation, taking into consideration the location, heights, and spacing with other structures.

7.5 Radio and TV Towers and Similar Skeletal Structures

(1) Top Level

On a radio, TV tower or similar skeletal structure, one level of light units is installed within 3 m of the highest point of the main structure.

(2) Intermediate Levels

On a skeletal structure referred to in subsection (1):

  1. (a) the number of levels of light units to be installed depends on the height of the structure, excluding any appurtenances, and is determined in accordance with Figure 7-1; and
  2. (b) at least three lights are installed on each intermediate level and mounted to ensure that the effective intensity of the full horizontal beam coverage is not impaired by the structural members.

(3) Appurtenances

Where a skeletal structure has an appurtenance in excess of 12 m in height above it:

  1. (a) a medium intensity white flashing light is installed in accordance with subsection 6.4(5); and
  2. (b) the light referred to in paragraph (a) operates 24 hours a day and flashes simultaneously with the rest of the lighting system installed on the structure.

7.6 Chimneys, Flare Stacks and Similar Solid Structures

(1) Lighting Levels and Location

The number of levels of light units required to be installed on a chimney, flare stack or similar solid structure is determined in accordance with Figure 7-1.

(2) Number of Light Units per Level

The number of light units required to be installed on each level of the high intensity white flashing lighting system of a structure referred to in subsection (1), is be determined in accordance with Table 5-1.

(3) Hyperbolic Cooling Towers

Where any cooling tower of a nuclear generating station:

  1. (a) is 180 m in height or less AGL, intermediate light levels may be omitted; or
  2. (b) exceeds 180 m AGL in height, a second level of light units is installed approximately at the midpoint of the structure and in a vertical line with the top level of lights.

7.7 Prominent Buildings, Structures and Similar Extensive Objects

(1) Individual buildings, structures or objects having a similar height above ground and located not more than 60 m apart within a group of obstructions may be considered as an extensive obstruction for lighting purposes, in which case the group displays CL-856 white flashing light units to indicate the extent of the obstruction as specified in this section.

Information Note:  Owing to the glare factor, caution shall be used in the application of high intensity white flashing lights.

(2) On a structure 60 m or less in both horizontal dimensions, a CL-856 light is displayed:

  1. (a) on the highest point at each end of the major axis of the obstruction; or
  2. (b) in the centre of the highest point.

(3) Structures Exceeding 60 m in any Horizontal Dimension

  1. (a) On a structure exceeding 60 m in any horizontal dimension, CL-856 light units are displayed on:
    1. (i) the highest point at each end of the obstruction, and
    2. (ii) the highest points for each 60 m, or fraction thereof, for the overall length of the major axis.
  2. (b) If the minor axis of a structure exceeding 60 m in one of its horizontal dimensions is 60 m or less in length, the lights referred to in paragraph (a) may be installed as a row along the middle or along either side, as shown in Figure 5-3.

(4) Structures Exceeding 150 m AGL

Top Lights

  1. (a) A CL-856 white flashing light unit is installed on the highest point at each end of a structure exceeding 150 m AGL in height.
  2. (b) At intermediate levels of the structure,
    1. (i) a CL-856 white flashing unit is displayed for each 150 m or fraction thereof,
    2. (ii) the vertical position of the intermediate lights is equidistant between the top lights and the ground level as the shape and type of obstruction will permit, and
    3. (iii) a CL-856 white flashing unit is displayed at each outside corner on each level with the remaining lights evenly spaced between the corner lights.

CHAPTER 8   DUAL RED/WHITE MEDIUM INTENSITY LIGHTING SYSTEM, CONFIGURATION “E”

8.1 Scope 

Chapter 8 governs obstruction lighting that uses a configuration “E” lighting system consisting of CL-810 steady burning red and CL-864 flashing red obstruction light units for nighttime operation and CL-865 medium intensity white flashing light units for daytime and twilight operation.

Information Note:  This lighting system may be used in lieu of operating a CL-865 medium intensity white flashing system at night, in order to avoid glare complaints particularly in populated urban areas.

8.2 Application

(1) The light units of the system are installed as required by the relevant provisions of

  1. (a) Chapter 4 for lighting in general;
  2. (b) Chapter 5 for red lighting; and
  3. (c) Chapter 6 for medium intensity lighting.

(2) The number of light levels needed is obtained from Figures 5-1 and 6-1 for the applicable components of the lighting system.

8.3 Operation

The lighting system is operated such that:

  1. (a) both the red and white systems are not operated at the same time;
  2. (b) there is no more than a 2-second delay when changing from one system to the other; and
  3. (c) outage of one of two lamps in the uppermost CL-864 red flashing beacon or outage of any uppermost red light causes the white obstruction lighting system to operate in its specified “night” step intensity.

8.4 Control Device

The lighting system is controlled such that:

  1. (a) a photocell device causes a change of operation from red to white lighting with an increase and decrease of the ambient light level;
  2. (b) the system automatically changes from white to red and subsequently from red to white when the northern sky illuminance, as indicated in Table 13-1, goes through the transitions of twilight to night and night to twilight respectively; and
  3. (c) where a malfunction requires the white lighting system to be operated during the night, the device causes operation at the lower intensity level.

8.5 Antenna or Similar Appurtenance Light

When a structure utilizing this dual lighting system is topped with an antenna or similar appurtenance exceeding 12 m in height above the structure:

  1. (a) a CL-865 medium intensity white flashing light and a CL-864 red flashing beacon is placed within 12 m from the tip of the appurtenance;
  2. (b) the CL-865 white light operates during daytime and twilight and the red light during nighttime; and
  3. (c) the lights required in paragraphs (a) and (b) flash simultaneously with the rest of the lighting system.

8.6 Omission of Marking

When medium intensity white lights are operated on a structure 150 m AGL or less during daytime and twilight, the markings required under this Standard may be omitted on the structure.

CHAPTER 9   DUAL RED/WHITE HIGH INTENSITY FLASHING SYSTEM, CONFIGURATION “F”

9.1 Scope

Chapter 9 governs obstruction lighting that uses a configuration “F” lighting system referred to in Table 4-2.

Information Note:  This lighting system may be used in lieu of operating a white flashing lighting system at night. There may be populated urban areas where the use of high intensity lights at night may cause environmental complaints.

9.2 Light Units

CL-810 and CL-864 red light units shall be used for night time lighting and CL-856 high intensity white flashing light units shall be used for daytime and twilight lighting.

9.3 Installation

The light units required under section 9.2 shall be installed in accordance with the relevant provisions of Chapter 4 for lighting in general, of Chapter 5 for red lighting and Chapter 7 for high intensity white flashing lighting.

9.4 Operation

A configuration “F” lighting system shall:

  1. (a) be operated in accordance with the requirements of:
    1. (i) Chapter 4 for lighting in general,
    2. (ii) Chapter 5 for red lighting, and
    3. (iii) Chapter 7 for high intensity white flashing lighting;
  2. (b) not have both red and white lighting systems operating at the same time; however, there shall be no more than a 2-second delay when changing from one colour of lighting system to the other; and
  3. (c) where an outage of one of two lamps in the uppermost CL-864 red beacon or an outage of any uppermost red light unit occurs, have the white lighting switched on and operating in its specified night mode of intensity.

9.5 Control Device

The light intensity of a configuration “F” lighting system shall be controlled by a photocell device set to operate in accordance with Table 13-1 for transition between day, twilight and night.

9.6 Antenna or Similar Appurtenance Light

  1. (1) Where a configuration “F” lighting system is used on a building, structure or object that is topped with an antenna or similar appurtenance exceeding 12 m in height above it, both a CL-864 medium red flashing and a CL-865 medium intensity white flashing light unit is placed within 12 m from the tip of the appurtenance.
  2. (2) The white light unit referred to in subsection (1) operates during daytime and twilight, and the red light unit during night time.

9.7 Omission of Marking

When high intensity white flashing light units are operated during daytime and twilight, any day marking otherwise required under Chapter 3 to be displayed on the building, structure or object may be omitted.

CHAPTER 10   MARKING AND LIGHTING OF CATENARIES

10.1 Scope

Chapter 10 governs obstruction marking and lighting of a catenary wire and a catenary support structure.

10.2 Marking of Catenary Support Structures

A support structure of a power line is painted in alternate bands of orange and white in accordance with section 3.4, and is clear of trees and brush insofar as practicable [refer to information note in section 2.1.]

10.3 Shore Markers

Where, according to a risk assessment, the marking of a support structure would not clearly indicate the presence of a catenary, a shore marker is displayed as indicated in Figure 10-1, and:

  1. (a) is painted aviation orange and white
  2. (b) is either of:
    1. (i) a panel type, designed as a 6 m square panel with a 5 m diameter aviation orange dot, or
    2. (ii) a pole type.

10.4 Catenary Markers

Spherical markers are displayed on a catenary, as indicated in Figure 10-1 and as specified below, unless equivalent markings are approved by the Minister as a result of a risk assessment:

(1) Dimensions and spacing

Each marker has the following diameters and associated spacings on the catenary:

  1. (a) 50 cm diameter and 30 m spacing;
  2. (b) 75 cm diameter and 45 m spacing;
  3. (c) 150 cm diameter and 90 to 120 m spacing; and
  4. (d) other dimensions may be approved by the Minister, if necessary, as determined by a risk assessment, provided that due consideration is given to the overall obstacle avoidance distances referred to in section 2.1.

(2) Minimum Quantity

Where the length of the catenary span is less than twice the spacing, depending on the size of marker as that indicated in subsection (1), not less than two markers are used.

(3) Location

Markers are displayed:

  1. (a) on the highest wire or by other means at the same height; or
  2. (b) where there is more than one wire at the highest level, the markers may be installed alternately along each wire, as indicated in Figure 10-1, as long as the distance between adjacent markers meets the spacing standard.

Information Note:  This method will allow the weight and wind loading factors to be distributed.

(4) Colour Pattern

Markers have the following colour patterns:

  1. (a) on overhead wires, they are marked by alternating solid colour spheres of orange and white;
  2. (b) an orange marker is placed at each end of the overhead wire and its spacing adjusted to accommodate the rest of the markers; and
  3. (c) when less than four markers are needed, they are all orange.

10.5 Omission of Marking

Marking of a catenary wire or a support structure may be omitted, where:

  1. (a) the height of the support structure is 150 m AGL or less, and CL-866 lights are installed on the support structure and operated 24 hours a day; or
  2. (b) CL-857 high intensity white flashing light units are installed on the support structure and operated 24 hours a day.

10.6 Lighting of Catenary Wires

(1) Light units are installed along a catenary wire, either separately or in combination with a day marker, provided that the light units are:

  1. (a) used on transmission line catenary near airports, heliports, across rivers, canyons, lakes, and similar geographical features;
  2. (b) visible by a pilot from any normal angle of approach;
  3. (c) meet the requirements specified for the CL-810 light unit;
  4. (d) used on the highest energized line;
  5. (e) located within 6 m of the day marker if the light unit is separate from the day marker; and
  6. (f) spaced at the same interval as that required for the day markers on the same catenary.

(2) Lighting of catenary wires is not required where lighting in accordance with section 10.7 or 10.8 is installed, unless otherwise determined following a risk assessment.

10.7 Daytime Lighting of Catenary Support Structures

Where a support structure or a power line crossing are assessed by the Minister, as a result of an Aeronautical Evaluation, as likely to be inadequately marked by the painting and markers specified in Chapter 10, the support structure is lighted in daytime by medium or high intensity white flashing light units as follows:

Support Structures 150 m AGL or less

  1. (a) One of the following lighting systems is approved by the Minister as part of the Aeronautical Evaluation for the catenary, where no portion of the obstruction exceeds 150 m AGL:
    1. (i) a CL-866 medium intensity white flashing white lighting system, or
    2. (ii) a CL-866/CL-885 dual medium intensity flashing lighting system.

Support Structures exceeding 150 m AGL

  1. (b) One of the following lighting systems is used for the catenary, where the obstruction exceeds 150 m AGL:
    1. (i) a CL-857 high intensity white flashing lighting system, or
    2. (ii) a CL-857/CL-855 dual high intensity flashing lighting system.

Levels of Light Units

  1. (c) The lighting system includes light levels displayed as follows:
    1. (i) a system of three levels of sequentially flashing light units is installed on each supporting structure or adjacent terrain as follows:
      1. (A) at the top of the structure,
      2. (B) at the lowest point in the catenary, and
      3. (C) approximately midway between the other two light levels and at least 15 m from the other two levels, except that the middle light level may be deleted when the distance between the top and the bottom light levels is less than 30 m,
    2. (ii) the maximum vertical spacing tolerance allowed to accommodate structural limitations is 20 percent of the uniform spacing of the bottom and middle light units, and
    3. (iii) if the base of the supporting structure is higher than the lowest point in the catenary, such as a canyon crossing, the required light units are installed on the adjacent terrain at the level of the lowest point in the catenary.

Light Coverage

  1. (d) The photometric coverage requirements for the light units are:
    1. (i) in the case of the top level of light units:
      1. (A) one or more lights are installed, subject to clause (B), at the top of the structure to provide 360-degree coverage ensuring an unobstructed view to a pilot from any normal angle of approach,
      2. (B) if the installation presents a potential danger to maintenance personnel, or when necessary for lightning protection, the top level of light units may be mounted not more than 6 m below the highest point of the structure, provided that due consideration is given to the overall obstacle avoidance distances referred to in section 2.1, and
    2. (ii) in the case of the middle and bottom levels of light units:
      1. (A) the light units at the middle level and bottom level are installed so as to provide a minimum of 180-degree coverage cantered perpendicular to the flyway,
      2. (B) where a catenary crossing is situated near a bend in a river, canyon or similar geographical feature, or where it is not perpendicular to the flyway, the horizontal beam is directed to provide the most effective light coverage to warn pilots approaching the catenary wires from any normal angle of approach, and
      3. (C) where a catenary involves three or more supporting structures, the inner structure or structures are equipped with enough light units per level to provide 360-degree coverage.

Flash Sequence

  1. (e) The lighting system flashes as follows:
    1. (i) each light unit has a flash frequency of 60 flashes per minute or 1 second per flash cycle (± 5 percent),
    2. (ii) the flash sequence of the levels of light units is middle, top, and then bottom,
    3. (iii) the interval between top and bottom flashes is about twice the interval between middle and top flashes, and
    4. (iv) the interval between the end of one sequence and the beginning of the next is about 10 times the interval between middle and top flashes.

Synchronization

  1. (f) On the lighting system used for associated catenary support structures:
    1. (i) the corresponding light levels flash simultaneously, if practicable, and
    2. (ii) where three or more supporting structures are involved and the inner structure or structures are equipped with enough light units per level to provide 360-degree coverage, the light units for each level flash simultaneously.

Photocell Control

  1. (g) Where a medium or high intensity lighting system is used for a catenary crossing, the light intensity of the system is automatically controlled by photocell devices whose day, twilight and night transition settings conform to the specifications set out in Table 13–1.

Photometric Characteristics

  1. (h) The photometric characteristics of the lighting system are in accordance with the requirements set out in Chapter 13.

10.8 Lighting with use of ADS

Where an Aircraft Detection System (ADS) is installed as specified in Chapter 15, each support structure is lighted by one of the following medium intensity lighting systems as illustrated in Figure 10-2b:

  1. (a) a CL-866 medium intensity white flashing white lighting system, or
  2. (b) a CL-866/CL-885 dual medium intensity flashing lighting system.

CHAPTER 11   MARKING AND LIGHTING OF MOORED BALLOONS AND KITES

11.1 Scope

Chapter 11 governs the marking and lighting of moored balloons and kites.

11.2 Application

A balloon that is 1.8 m or more in diameter or exceeds 3 cubic meters of gas capacity, or a kite weighing more than 2.27 kg are marked and lighted in accordance with the requirements specified in Chapter 11.

11.3 Markers

Markers are attached, during daytime, to the mooring lines of a balloon or to the tether cable of a kite in accordance with this section.

(1) Location

Markers are displayed at not more than 15 m intervals along the mooring lines of the balloon or the tether cable of the kite, beginning at 45 m from the point of attachment on the ground.

(2) Characteristics

Markers required under subsection (1) are:

  1. (a) rectangular in shape, 0.15 m wide and 3.0 m in length; and
  2. (b) of the following colour patterns:
    1. (i) solid orange, or
    2. (ii) of two triangular sections, one of aviation orange and the other aviation white, combined to form a rectangle.

11.4 Lighting

At night, a moored balloon or a kite is equipped with the lighting devices specified in this section.

(1) Location

  1. (a) Lights having the characteristics specified in subsection (2) are located on the top of the object in a fashion as to be viewable from all directions, except that where the dimensions of the object are in excess of 45 m, additional lights of the same type are installed on the top, nose section, tail section, and on the mooring lines or tether cable approximately 5 m below the balloon or kite, so as to define its shape and size; and
  2. (b) Additional lights are equally spaced along the mooring line or tether cable for each 107 m, or fraction thereof, commencing at 90 m AGL.

(2) Characteristics

  1. (a) For operations from 90 m AGL to 150 m AGL, red flashing or white flashing lights of 32.5 effective candelas are installed on the moored balloon and on its mooring lines, or on the tether cable of the kite.
  2. (b) For operations above 150 m AGL, white flashes of 500 effective candela are installed on the moored balloon and on its mooring line, or on the tether cable of a kite.

(3) Control

Lighting required on a moored balloon or on a kite is provided with a means of control such as, for instance a photocell, for day and night time operation in accordance with Table 13-1.

CHAPTER 12   WIND TURBINES AND WIND FARMS

12.1 Scope

Chapter 12 governs the marking and lighting of a wind turbine and a wind turbine farm.

Information Note 1:  The definition of wind farm is based on the premise that the installation of three wind turbines is the first instance for which omission of lighting might be made. Since the exterior wind turbines [on the perimeter] of a wind farm are to be lighted, a grouping of only two wind turbines would require that both be lighted. In the case of three wind turbines lighting of the inner wind turbine may be omitted depending upon spacing.

Information Note 2:  The application of these requirements can vary in accordance with the provisions of this Standard depending on terrain features, geographic location, overall layout of the structures, and normal angles of approach.

Information Note 3:  The provision of lighting on wind turbines and wind farms should be done in a fashion as to minimize the possibility of bird fatalities and interference with nighttime astronomical study.

12.2 Wind turbines of Total Height Equal to or Less than 150 m

(1) Marking Requirements

For the purpose of Day Protection, a single wind turbine and wind turbines of a wind farm are painted a white or an off-white colour.

Information Note:  The above specified colours can be found in the RAL colour system as ...

white - #9010

off-white - #7035 (light grey)

(2) Lighting Requirements

For Night Protection, a single wind turbine and wind turbines of a wind farm are lighted as illustrated in Figure 12-1 and as follows:

  1. (a) For a single wind turbine,
    1. (i) A wind turbine is lighted with use of a CL-864 medium intensity red flashing beacon for nighttime hours.
    2. (ii) The lighting fixtures required under subparagraph (i) are mounted to ensure an unobstructed view by a pilot approaching from all angles of aircraft approach.
  2. (b) For a wind farm;
    1. (i) The group of wind turbines composing a wind farm is indicated to pilots by installation of CL-864 medium intensity red flashing beacons on specified wind turbines on the perimeter of the wind farm.
    2. (ii) The "wind farm indicators" of subparagraph (i) are located so as to define the wind farm and spaced at a horizontal distance in the order of 900 m for given directions of aircraft approach.
    3. (iii) In addition to the wind farm indicators of subparagraph (ii) the dominant [highest in absolute height] wind turbine within the wind farm is also required to be lighted. This requirement for lighting is dependent upon the degree of dominance deemed to produce a hazard to air navigation.
    4. (iv) A tower or other structure within the wind farm, which in being lighted provides the same level of safety, may be used for installation of a wind farm indicator.
    5. (v) Because of the variation in configuration of wind farms, the provision of lighting is also subject to a risk assessment taking into account such factors as the general profile of the group, the location of the wind farm in relation to nearby aerodromes or recognized VFR flight routes, and the anticipated air traffic.
    6. (vi) All indicator lighting provided for a wind farm flashes simultaneously.

12.3 Wind turbines of Total Height Exceeding 150 m

The provision of marking and lighting for wind turbines higher than 150 m is determined through means of a risk assessment.

12.4 Continued Illumination

The lighting provided for a wind turbine or wind farm is so designed such that it can draw power from the electrical grid for continued illumination even though the wind turbine on which it is mounted ceases operation.

Information Note:  The above standard is based upon the premise that the lighting of a non-operating wind turbine can obtain power from the grid. However, it also recognizes that continued illumination will not be possible should the electrical grid itself fail.

CHAPTER 13   OBSTRUCTION LIGHTING CHARACTERISTICS

13.1 Scope

Chapter 13 governs the overall technical characteristics of obstruction lighting equipment required under this Standard.

13.2 Equipment Specification

The specifications covering electrotechnical requirements of obstruction lighting equipment are contained in Appendix B.

13.3 Photometrics

The photometric output of obstruction light units required under this Standard is in accordance with Table 13-2. Table 13-1 provides an illustration of these photometric requirements.

13.4 Photocell Control

In order to have automatic control of obstruction lighting systems, these are provided with a photocell device with settings as shown in Table 13-1.

Table 13-1:  Photocell Control Settings

Operational transition
occurs from – to
at a north sky illuminance of

day

twilight

600 to 350 lux

twilight

Night

350 to 20 lux

night

twilight

20 to 350 lux

twilight

Day

350 to 600 lux

Table 13-2:  Obstruction Light Photometric Distribution

 

 

 

Minimum Intensity (candelas) (a)(g)

 

Intensity (candelas) at given elevation angles when the light is levelled (c)

Light Type

Colour

Signal type

day

twilight

night

Vert. beam spread (b)

- 10º (d)

- 1º (e)

± 0º (e)

+ 2.5º

+12.5º

CL810

red

fixed

N/A

32

32

10º

-----

-----

-----

32 min

32 min

CL864

red

20-40 fpm

N/A

N/A

2000

3º min

-----

50% min
75% max

100% min

-----

-----

CL865 (f)

white (f)

40 fpm

20,000

20,000

2000

3º min

3% max

50% min
75% max

100% min

-----

-----

CL866

white

60 fpm

20,000

20,000

2000

3º min

3% max

50% min
75% max

100% min

-----

-----

CL885

red

60 fpm

N/A

N/A

2000

3º min

-----

50% min
75% max

100% min

-----

-----

CL856

white

40 fpm

270,000

20,000

2000

3º min

3% max

50% min
75% max

100% min

-----

-----

CL857

white

60 fpm

140,000

20,000

2000

3º min

3% max

50% min
75% max

100% min

-----

-----

  1. (a) Effective intensity, as determined in accordance with Appendix B.
  2. (b) Beam spread is defined as the angle between two directions in a plane for which the intensity is equal to 50% of the lower tolerance value of the intensity shown in columns 4, 5 and 6. The beam pattern is not necessarily symmetrical about the elevation angle at which the peak intensity occurs.
  3. (c) Elevation (vertical) angles are referenced to the horizontal.
  4. (d) Intensity at any specified horizontal radial as a percentage of the actual peak intensity at the same radial when operated at each of the intensities shown in columns 4, 5 and 6.
  5. (e) Intensity at any specified horizontal radial as a factor of the lower tolerance value of the intensity shown in columns 4, 5 and 6.
  6. (f) In the case of rotating type CL-865, one-third of the flash display is red in colour. e.g. WWRWWR
  7. (g) For flashing lights a tolerance on the nominal of ±25%.

CHAPTER 14   MAINTENANCE

14.1 Scope

Chapter 14 governs the maintenance of marking and lighting required under this Standard.

14.2 Marking

The surfaces of a building, structure or object required to be marked with paint, are repainted when the colour changes noticeably or when its effectiveness is reduced by scaling, oxidization, chipping or layers of contamination.

Information Note:  In-Service Aviation Orange Colour Tolerance Charts are available from private suppliers for determining when repainting is required. The colour should be sampled on the upper half of the structure, since weathering is greater there.

14.3 Lighting

(1) Operating Voltage

To ensure proper candela output:

  1. (a) for light units with incandescent lamps, the voltage provided to the lamp socket shall be within ± 3 percent of the rated voltage of the lamp; or
  2. (b) for light units with strobe [capacitor discharge] lamps, the input voltage to the power supply shall be within ±10 percent of rated voltage of the power supply.

(2) Lamp Replacement

  1. (a) A lamp in a light unit is replaced immediately upon failure or after being operated for not more than 75 percent of its rated life.
  2. (b) A flashtube in a light unit is replaced:
    1. (i) immediately upon failure, or
    2. (ii) when the peak effective intensity falls below specification limits, when the fixture begins skipping flashes or at the manufacturer’s recommended intervals, whichever occurs first.

(3) Fixture Lenses

Owing to the effects of harsh environments, a beacon lense is visually inspected for ultraviolet damage, cracks, crazing, dirt build up or similar forms of degradation, to ensure that the required certified light output has not been adversely affected.

14.4 Removal of Obscuring Effects

Regular inspection takes place and remedial action undertaken to ensure that effects, such as the growth of vegetation, do not obscure the pilot's view of any portion of marking or lighting displayed pursuant to this Standard.

CHAPTER 15   AIRCRAFT DETECTION SYSTEM (ADS)

15.1 Scope

Chapter 15 governs Aircraft Detection Systems (ADS) which are used to turn on obstruction lighting systems upon detection of an approaching aircraft. The system is radar based and can detect and analyze the flight path [position, altitude, heading and ground speed] of an aircraft so as to determine the possibility of potential collision with an object. If the flight path is such that the aircraft may impact the obstacle, then the obstacle lights are turned on and a later audio signal is transmitted. The purpose of the system is to enable the lighting to be off when not needed [absence of aircraft] and thereby to reduce energy consumption, and glare to the public.

15.2 Impact Boundary

(1) The impact boundary is a 3-dimensional boundary around the obstacle approved by the Minister, so as to establish the distance [in terms of seconds] from the location of the detected aircraft to a point of impact on this boundary.

(2) The impact boundary is at a distance of 60 m to 300 m from the actual physical sides of the obstacle, as shown in Figure 15-1.

Note: An impact boundary for a catenary is shown in Figure 15-1. Different shapes of impact boundary may be required for different obstacles. In the case of lengthy or large area objects, more than one ADS radar may be required.

(3) In vertical dimension, the impact boundary extends 60 m above the highest portion of the obstacle.

15.3 Operation

(1) The system has two primary functions: to turn on the obstacle lights and to emit an audio signal. These functions are performed with respect to the detection of the aircraft within a specified minimum flight time to the impact boundary for both a heading directly towards the impact boundary as well as a potential manoeuvre towards the impact boundary.

(2) The system has the following minimum timings for light and audio signal activation with respect to the speed of the aircraft and time from the impact boundary:

 

Aircraft speed
knots

Aircraft speed
m/s

Time from Impact Boundary
(seconds)

90

46.3

30

120

61.7

30

165

84.9

30

180

92.6

30

250

128.6

20

(3) Potential Manoeuvre to Impact Boundary

Note:  The following addresses the case of aircraft that are not on a direct flight path to impact, but have the potential for impact.

  1. (a) The ADS detects and causes light and audio signal activation per 15.3.2 for aircraft flying in the horizontal plane that would have a potential of impact if it were to conduct a turning manoeuvre of up to 2g. Refer to Figure 15-3.
  2. (b) The ADS detects and causes light and audio signal activation per 15.3.2 for aircraft flying in the horizontal plane that would have a potential of impact if it were to conduct a descent of rate of up to 2.5m/s [500 ft per minute]. Refer to Figure 15-3.

(4) Lighting

  1. (a) Once the lighting is activated upon aircraft detection, the lighting is maintained on for a period of at least 60 seconds.
  2. (b) The lighting for use with ADS is of a design such that it will provide full intensity within 2 seconds of activation.

(5) Audio Signal

  1. (a) The audio signal consists of a 3 note chime followed by a worded message indicating the type of obstacle as determined locally. For example, for a catenary crossing, the term "power line" may be used. The signal is repeated a total of 6 times for slow speed aircraft and 3 times for high speed aircraft [>250 knots], for a total duration of 12 seconds and 6 seconds respectively.
  2. (b) The audio signal is limited in range so as to not interfere with other non-ADS broadcasts. The limitation of range is tested using standard General Aviation VHF radio and antenna equipment while the ADS VHF transmitter is transmitting a continuous test signal, range limit is where the perceived signal quality comes below level 4.

    Note 1:  A limited range represented by a volume of space defined by a cylinder centred on the ADS unit with a radius of 7 km and height of 1.8 km, is recommended.

    Note 2:  In the radio terminology, the quality of the radio signal is rated on a scale from 1 through 5, where 1 is the worst (unreadable) and 5 is best. A quality of 4 is fully readable, when below 4 the audio signal is degraded below an acceptable level.
  3. (c) The audio signal is broadcast simultaneously on multiple frequencies in the VHF band over the range of 118 to 136 MHz. The frequencies are selected as appropriate for local requirements.

(6) Warning Zones

Note:  The ADS may be considered to establish "warning zones" around the obstacle based upon the timings for light activation and audio signal transmission in relation to the impact boundary.

  1. (a) If the aircraft enters the audio signal warning zone, an audio signal is transmitted. If the aircraft remains within this zone no additional audio signals are provided. A new signal will be provided, if the aircraft leaves the zone and then re-enters.
  2. (b) If the aircraft enters the light activation warning zone, the lights are turned on and will continue to be illuminated for the period specified in subsection 15.3.4. If the aircraft remains within this zone beyond the specified period, the lights will turn off. The lights will be re-activated, when the aircraft leaves the zone and then re-enters.

(7) Frequencies

  1. (a) Audio signal radio broadcasts comply with applicable Industry Canada guidelines and permit requirements.
  2. (b) The radar frequencies are selected so as to not cause interference with other radar operations.

15.4 Monitoring

The ADS has continuous electronic monitoring to detect failure of the major components.

  1. (a) Radar or Communications Failure:  The occurrence of failure of the radar or of the communication link to the lights cause the lighting to be turned on continuously, the audio signal deactivated and an alarm given to a 24 hour staffed station. There is provision for immediate issuance of a NOTAM from this station. The communication status and operational status of the system are confirmed at least once every 24 hours.
  2. (b) Obstruction Lights Failure:  If a light outage occurs, the audio warning function remains active, the monitoring station is notified and a NOTAM issued. Corrective action is taken as soon as possible to restore the light.

15.5 Self Test

Unless the system has been activated at least once within a 24 hour period by aircraft, the system is activated for self test at least once within a 24 hour interval to verify the operational status.

15.6 Radar Unit

The radar unit is provided with a battery backup supply having a capacity for 24 hours of operation, to enable communication of external power supply failure to the lights.

15.7 Submission of Application for Use

The design and function of each control device is described in the ADS application. The control device description includes:  functionality, selectable features, program modification, maintenance actions, failure/monitoring provisions and any reporting functions. The reportable functions are described and the methodology detailed for accumulating information.

15.8 Commissioning Test

The ADS installation is subject to a commissioning test to verify:

  1. (a) the required performance of the system,
  2. (b) absence of any interferences of the radar unit with other radars in the area, and
  3. (c) that the audio does not present a hazard to other aircraft communications not in proximity to the obstruction hazard.

APPENDIX A

Transport Canada Civil Aviation Regions

Aerodromes And Air Navigation

Region

Address

Telephone

Pacific

Transport Canada
Suite 820, 800 Burrard St.
Vancouver, British Columbia V6Z 2J8

(604) 666-8777


e-mail: pacaocf@tc.gc.ca

Prairie and Northern

for
Alberta,
Saskatchewan,
Manitoba,
Yukon
Nunavut and
NWT

Transport Canada
1100, 9700 Jasper Avenue
Edmonton, Alberta T5J 4E6

1-888- 463-0521
e-mail:  CASPNR-SACRPN@tc.gc.ca

 

Ontario

Transport Canada
4900 Yonge Street, 4th Floor
Toronto, Ontario M2N 6A5

(416) 952-0215
or
1-877-231-2330
e-mail: CASO-SACO@tc.gc.ca

Quebec

Transport Canada
700 Leigh Capréol
Dorval, Quebec H4Y 1G7

(514) 633-3252

e-mail:
aerodromes.quebec@tc.gc.ca

Atlantic

for
Nova Scotia,
New Brunswick,
Prince Edward Island and
Newfoundland and Labrador

Transport Canada
P.O. Box 42
Moncton, New Brunswick E1C 8K6

 

1-800-305-2059

e-mail: casa-saca@tc.gc.ca

NAV CANADA

If there is a failure of obstacle lighting and it is to be reported through means of a NOTAM, one should contact the NAV CANADA Flight Information Centre in which the object is located.

Nav Canada Flight Information Centre (FIC)

Kamloops

1-866-541-4101

Quebec

1-866-541-4105

Edmonton

1-866-541-4102

Halifax

1-866-541-4106

Winnipeg

1-866-541-4103

Whitehorse

1-866-541-4107

London

1-866-541-4104

North Bay

1-866-541-4109

APPENDIX B

SPECIFICATION FOR OBSTRUCTION LIGHTING EQUIPMENT

1.0 INTRODUCTION

1.1 Scope

This specification sets forth design and qualification test criteria for obstruction lighting equipment used to increase conspicuity of structures to permit early obstruction recognition by pilots.

1.2 Equipment Classification

Light

Intensity type

colour

Flash rate

Flash Cycle Duration

CL-810

low

red

steady burning

n/a

CL-856

high

white

40fpm

1500ms

CL-857

high

white

60fpm

1000ms

CL-864

medium

red

20 to 40fpm

3000 to 1500ms

CL-865

medium

white

40fpm

1500ms

CL-866

medium

white

60fpm

1000ms

CL-885

medium

red

60fpm

1000ms

fpm = flashes per minute

2.0 REFERENCE DOCUMENTS

2.1 General

It is intended that the following reference documents be used in conjunction with this document:

2.2 Transport Canada

Standard 621 - Obstruction Marking and Lighting

2.3 Federal Aviation Administration (FAA) Advisory Circulars (ACs)

AC 70/7460-1 Obstruction Marking and Lighting

AC 150/5345-43f Specification for Obstruction Lighting Equipment

Note:  The above FAA circulars are referenced for reason of a linkage with respect to the basis of this specification. However, the reader is cautioned that some of the requirements contained in K-310 differ from that in the FAA circulars.

2.4 Military Standards and Specifications

MIL-STD-810F Environmental Engineering Considerations and Laboratory Tests

MIL-C-7989 Cover, Light-Transmitting, for Aeronautical Lights, General Specification for

2.5 Institute of Electrical and Electronics Engineers (IEEE) Publications

IEEE C62.41-1991  IEEE Recommended Practice on Surge Voltages in Low-Voltage AC Power Circuits

IEEE C62.45  IEEE Recommended Practice on Surge Testing for Equipment Connected to Low-Voltage (1000 V and Less) AC Power Circuits

2.6 Illuminating Engineering Society (IES) Publications

IES Handbook - Reference and Application Volume, 8th Edition, 1993, Flashing Light Signals, pp. 96-97

2.7 International Civil Aviation Organization (ICAO)

Annex 14 Volume 1, Aerodrome Design and Operations

2.8 Document Sources

Copies of military standards and specifications may be obtained from:

DAPS/DODSSP
Building 4, Section D
700 Robbins Avenue
Philadelphia, PA 19111-5094

Tel:  (215) 697-2179
Website: dodssp.daps.dla.mil

Copies of IEEE standards may be obtained from:

IEEE Customer Service Center
445 Hoes Lane
P.O. Box 1331
Piscataway, NJ 08855-1331

Tel:  (800) 678-4333 
email:  storehelp@ieee.org
website:  http://www.ieee.org/about/contact/customer1.htmlshop.ieee.org/ieeestore

Copies of IES of North America (IESNA) documents may be obtained from:

website:  www.techstreet.com
or
website:  http://www.ies.org/store/www.iesna.org/shop/

Copies of ICAO documents may be obtained from:

ICAO, Document Sales Unit
999 University Street
Montreal, Quebec, Canada H3C 5H7

Tel:  (514) 954-8022
email:  sales@incao.int

3.0 EQUIPMENT REQUIREMENTS

3.1 General

This section addresses environmental, design, and photometric requirements for obstruction light equipment. Criteria for selecting the proper obstruction lighting equipment, installation tolerances, and administrative information are in Standard 621, Obstruction Marking and Lighting.

3.2 Environmental Requirements

Obstruction lighting equipment is designed for continuous operation under the following conditions:

  1. (a) Temperature:
    Storage/shipping:  -55 degrees Celsius to +55 degrees Celsius
    Operating:  -40 degrees Celsius to +55 degrees Celsius
  2. (b) Humidity. 95 percent relative humidity.
  3. (c) Wind. Wind speeds up to 240 kilometres per hour.
  4. (d) Wind-blown Rain. Exposure to wind-blown rain from any direction.
  5. (e) Salt Fog. Exposure to salt-laden atmosphere.
  6. (f) Sunshine. Exposure to solar radiation.
3.3 Design Requirements

3.3.1 Light Unit

Materials used within the light unit are selected for compatibility with their environment. All plastic lens parts (including gaskets), that are exposed to ultraviolet radiation or ozone gas do not change colour, crack, check, disintegrate, or be otherwise degraded (photometry remains compliant). Each light unit is an independent unit and flashes at the specified intensity or at its highest intensity when control signals are absent.

3.3.2 Light Covers

Light-transmitting covers for light units are per the requirements in MIL-C-7989. In addition, if plastic covers are used, they are resistant to checking, crazing, or colour changes caused by ultraviolet radiation or ozone gas exposure.

3.3.3 Light Colours

The aviation red is per ICAO Annex 14, Volume 1, Appendix 1, Colours for Aeronautical Ground Lights, at operating temperature within the following chromaticity boundaries for the colour red:

purple boundary

y  =  0.980 - x

yellow boundary

y  =  0.335

 

x + y + z = 1

Xenon flashtube emission or a colour temperature range from 4,000 to 8,000 degrees Kelvin is acceptable for white obstruction lights.

3.3.3.1 Light Colour During Daytime

CL-810 obstruction lights do not require a non-powered colour during daytime viewing.

3.3.4 Aiming (for CL-856 and CL-857)

Light units have a method for adjustment of the vertical aiming angle between 0 and +8 degrees. A spirit level or other device is provided as part of each light unit for setting the vertical aiming angle of the light beam with an accuracy of ± degree.

3.3.5 Control Unit

3.3.5.1 White Flashing Obstruction Lighting Systems

The control unit shall set the system's flash rate, intensity and sequence and shall be capable of controlling light units up to a distance of 762 m. If the control unit or control wiring fails, the light units continue to flash at the flash rate indicated in Table 1. Failure of an intensity step change circuit shall cause all light units to remain operating at their proper intensity or alternatively to operate at the high intensity step.

3.3.5.1.1 Monitoring. Each light unit is monitored for FLASH/FAIL status. FAIL status is defined as either of the following conditions:  unit misses four or more consecutive flashes; unit flashes at wrong intensity step during day operation or failure of the continuous movement of the rotating device for rotating type flashing lights. Monitoring is fail safe (i.e. active signals for FLASH and absence of signals for FAIL). There is a provision to permit connection to a remote alarm device (supplied by others or as an option) to indicate the system and individual light unit FLASH/FAIL status.

3.3.5.1.2 In addition to the above, the control unit displays the status of each light unit. An intensity control override switch is also mounted in the enclosure to manually control light intensity during maintenance or in the event of a photoelectric control malfunction.

3.3.5.2 Red Flashing Obstruction Lighting Systems

The control unit sets the system flash rate and flash sequence. Failure of the flashing circuit causes the light units to energize and operate as steady burning lights.

An override switch is mounted on the control unit to manually control the lights during maintenance or in the event of a lack of a photoelectric control signal.

To ensure proper operation, all flashing red obstruction lights, inclusive of any associated system steady burning red lights, are certified with a control unit whether internal or external to the lighting unit.

3.3.5.2.1 Dual Lighting Systems

The control unit may be a separate unit or incorporated as part of either the white or red obstruction light control unit.

The control unit sets the operating mode for each light unit in the system. Outage of one of two lamps, or any failure in the device that causes a reduction in intensity of the horizontal beam or results in an outage in the uppermost red beacon (CL-864 unit) or outage of any uppermost red strobe, cause the white obstruction light system to operate in its specified "night" step intensity.

At no time should both red and white systems be on simultaneously.

Note:  This does not apply to a rotating type CL-865 which produces a WWRWWR signal. W = White; R = Red.

An override switch is mounted on the control unit to manually control the operating mode of the system during maintenance or in the event of a lack of a photoelectric control signal.

3.3.5.2.2 Monitoring

Each separate CL-864 light unit and each tier of CL-810 light units is monitored for FLASH/FAIL status.

"FAIL" is defined as outage of any lamp in a CL-864 light unit, outage of any one lamp in a tier of CL-810 light units, or failure of a flasher (steady on and/or total) for a CL-864 light unit. Monitor signals are fail safe (i.e., active signals for FLASH and absence of signals for FAIL).

There is a provision to permit connection to a remote alarm device, (supplied by others or by the light manufacturer) to indicate FLASH/FAIL status.

3.3.6 Input Voltage

The obstruction lighting equipment is designed to operate from the specified input voltage ±10  percent.

Incandescent lamps are operated to within ±3 percent of the rated lamp voltage to provide proper light output.

3.3.7 Radiated Emissions

Note:  Optional only. No equipment qualification is required.

Obstruction lighting that uses electronic circuitry to power the light source is classified as an incidental radiator. This applies to equipment that does not intentionally generate any radio frequency energy, but may create such energy as an incidental part of its intended operations.

Obstruction light systems employ sound engineering practices to minimize the risk of harmful interference.

3.3.8 Optional Arctic Kit

Light systems may be offered with an optional arctic kit to enable operation in temperatures below 
-40 degrees Celsius.

3.4 Performance Requirements

3.4.1 Photometric

The light units meet or exceed the minimum photometric requirements found in Standard 621. The values specified in Standard 621 are minimums and relate to minimum acquisition distances. The tolerance of ± 25 percent is a tolerance on meeting the nominal intensity value.

The effective intensity for flashing lights is calculated per Formula (1) by the method described for Flashing Light Signals in the IES Handbook, 1993 Reference and Application Volume, 8th Edition, Pages 96 and 97:

3.4.1 Photometric

Where:

Ie

=          Effective intensity (Candela)

I

=          Instantaneous intensity (Candela)

t1 , t2

=         Times in seconds of the beginning and end of that part of the flash when the value of I exceeds Ie. This choice of the times maximizes the value of Ie.

For discharge type flashing lights, the equipment provides the specified light output at the specified temperature extremes as the input voltage simultaneously varies by ±10 percent from nominal. The light intensity and beam distribution requirements for obstruction lighting equipment are specified in Chapter 13. All intensities listed are effective intensities (except steady-burning red obstruction lights) measured at the flash rate specified in Table 1. All incandescent lights will be tested as steady burning lights.

The frequency of the pulses is not less than 50 Hz and the interval tA- t1 does not vary by more than ±5% from the nominal value from pulse to pulse over the simultaneous extremes of temperature and input voltage.

The effective intensity for flashing lights is calculated per the following formula by the method described for Flashing Light Signals in the IES Handbook, 1993 Reference and Application Volume, 8th Edition, Pages 96 and 97:

3.4.1 Photometric

Where:

Ie

=          Effective intensity (Candela)

I

=          Instantaneous intensity (Candela)

t1 , t2

=         Times in seconds of the beginning and end of the first pulse flash when the value of I exceeds Ie. This choice of the times maximizes the value of Ie.

 

The effective intensity for multiple pulse flashes as used in strobe lights is calculated by:

3.4.1 Photometric

Where:

Ie

=          Effective intensity (Candela)

I

=          Instantaneous intensity (Candela)

t1 , t2

=         Times in seconds of the beginning and end of the first pulse flash when the value of I exceeds Ie. This choice of the times maximizes the value of Ie.

t3 , t4

=         Times in seconds of the beginning and end of the second pulse flash when the value of I exceeds Ie. This choice of the times maximizes the value of Ie.

tn-1 , tn

=         Times in seconds of the beginning and end of the last pulse flash when the value of I exceeds Ie. This choice of the times maximizes the value of Ie.

3.4.2 Flash Duration

Flash characteristics are defined in Table 1.

Table 1:  Flash Duration

Type

Intensity

Intensity Step

Flash rate(1)

Flash Duration(2)

CL-856

high

day & twilight

40fpm

less than 200ms

night

40fpm

between 100 and 250ms

CL-857

high

day & twilight

60fpm

less than 200ms

night

60fpm

between 100 and 250ms

CL-864

medium

night

20-40fpm

1/2 to 2/3 of flash period if incandescent lighting (note 3), and between 100 and 2/3 of flash cycle if other light source.

CL-865

medium

day & twilight

40fpm

less than 200ms

night

40fpm

between 100 and 2/3 of the flash cycle

CL-866

medium

day & twilight

60fpm

less than 200ms

night

60fpm

between 100 and 2/3 of the flash cycle

CL-885

medium

night

60fpm

1/2 to 2/3 of flash period if incandescent lighting (note 3), and between 100 and 2/3 of the flash cycle if other light source.

fpm = flashes per minute
ms = microseconds

NOTES:

(1) Flash rates have a tolerance of ±5 percent.

(2) When the effective flash duration is achieved by a group of short flashes, the short flashes are emitted at a rate of not less than 50 Hz.

(3) The light intensity during the "off" period is less than 10 percent of the peak effective intensity. The "off" period is at least 1/3 of the flash period.

3.4.3 System Flashing Requirements

3.4.3.1 Simultaneous Flashing Systems

All obstruction lights in systems composed of either CL-864 light units or CL-856 and/or CL–865 light units flash within 1/60 of a second of each other.

3.4.3.2 Sequenced Flashing Systems

  1. (a) Catenary support structure systems composed of CL-857, CL-866, or CL-885 light units have a sequenced flashing characteristic.
  2. (b) This system consists of three lighting levels on or near each supporting structure. One light level is near the top, one at the bottom or lowest point of the catenary, and one midway between the top and bottom.
  3. (c) The flash sequence is middle, top, and bottom.
  4. (d) The interval between top and bottom flashes is about twice the interval between middle and top flashes.
  5. (e) The interval between the end of one sequence and the beginning of the next is about 10 times the interval between middle and top flashes.
  6. (f) The time for the completion of one cycle is one second (±5 percent).

3.4.4 Intensity Step Changing

3.4.4.1 White Obstruction Lights

Refer Standard 621 for photocell settings for day, twilight and night operation.

3.4.4.2 Red Obstruction Lights

Refer Standard 621 for photocell settings for night operation.

4.0 EQUIPMENT QUALIFICATION REQUIREMENTS

4.1 Qualification Tests - General

Qualification tests are conducted on the light unit in the following order:

  1. (a) Initial photometric test, per section 4.2;
  2. (b) Environmental tests, per sections 4.3, 4.4, 4.5, 4.6, 4.7, 4.8 and 4.9 (in any order);
  3. (c) 1000 hours of continuous operation, per section 4.10;
  4. (d) System Operational Test, per section 4.10; and
  5. (e) Sampling Photometric Test, per section 4.2.

Sample photometric and system operational tests are conducted after completion of all environmental tests. The same unit(s) is used throughout the tests. The following tests are required to demonstrate compliance with this specification. The tests may be run on the control unit, power supply, and a single light unit, with a simulated load replacing the other light units. Equipment is tested as a complete system.

4.2 Photometric Test

A full photometric test as described in this section is performed before all environmental tests.

NOTE:  To verify proper colour correction, photometric testing conducted on alternative light source fixtures is done with a detector having an up to date calibration including spectral response data.

A sampling photometric retest is conducted after the unit has been operated continuously for 1000 hours with normal (12 hour) day/night cycling. This sampling consists of measuring the vertical beam pattern for compliance with photometric requirements at a minimum of two of the previously tested horizontal radials.

Light units are energized by the system power supply and control unit, and are tested for compliance with photometric requirements.

Incandescent lamps are tested at ±3 percent of their nominal voltage.

Red light intensity may be measured in white light and then calculated if the glassware manufacturer certifies the chromaticity and transmissivity values of the red filter material for the particular source. If more than one lamp type is to be used, the qualification testing is completed for each lamp type.

For a discharge type flashing system, if the power supply and optical head are separate components, the manufacturer demonstrates that the required photometrics are produced with the units separated by maximum and minimum recommended distances and connected by cable recommended by the manufacturer.

Photometric test results are in the forms of:

  1. (a) points over range of specified angles; and
  2. (b) Horizontal beam pattern: Polar plot (horizontal angle versus candela) with a minimum 30 degree spacing of test points.
4.3 High Temperature Test

The high temperature test is conducted per MIL-STD-810F, Method 501.4, Procedure II. The equipment is subjected to a constant temperature of +55 degrees Celsius for 4 hours after equipment temperature stabilization and be operated throughout the test.

NOTE:  For steady state temperature testing, consider thermal stabilization to be achieved when the temperatures of critical internal operating components are relatively constant. (Because of test item duty cycling or the operating characteristics, a constant temperature may never be achieved.)

During the test, the manufacturer demonstrates that the equipment maintains the specified flash rate and (for discharge type flashing light) the proper amount of energy is being delivered to the flashtube as the input voltage is varied by ±10 percent from nominal.

A visual examination is conducted after the equipment is removed from the chamber. Failure of the equipment to operate as specified is cause for rejection.

4.4 Low Temperature Test

The low temperature test is conducted per MIL-STD-810F, Method 502.4, Procedure II. The equipment is placed in a chamber that maintains a temperature of -55 degrees Celsius for shipping/storage requirements and -40 degrees Celsius for equipment operational requirements.

Equipment operation is demonstrated at the beginning of the test.

The equipment storage and shipping low temperature requirement is -55 degrees Celsius. The equipment is stabilized and cold soaked at the storage/shipping temperature for one hour. The test chamber is then ramped to the -40 degrees Celsius equipment operating temperature at no more than 14.4 degrees Celsius per minute to prevent thermal shock to the equipment.

The equipment, with input power off, is then exposed to a 24-hour soaking period at -40 degrees Celsius after which the equipment is turned on for one hour, and operates normally. The unit achieves specified flash rate and intensity within 1 minute after being energized. For rotating type beacons having HID (high intensity discharge) lamps and intended for continuous operation once installed, the unit achieves specified flash rate and the arc struck as to commence an output within 1 minute after being energized and achieves specified intensity within 5 minutes of being turned on. During the one hour of operation, the manufacturer demonstrates that the equipment maintains the specified flash rate and, for capacitor discharge type flashing lights (strobe lighting), the proper amount of energy is being delivered to the flashtube as the input voltage is varied by ±10 percent from nominal.

At the conclusion of the test, a visual inspection is conducted. Failure of the equipment to operate as specified is cause for rejection.

4.5 Rain Test

The wind-blown rain test is conducted per MIL-STD-810F, Method 506.4, Procedure I, paragraph 4.4.2. The rain is at a rate of 132mm/hour with an exposure time of 30 minutes per side. The equipment is operated throughout the test. Failure of the equipment to operate as specified is cause for rejection.

4.6 Wind Test

Evidence is provided, either by testing or by calculation of mechanical force, to demonstrate that installed light units meet the wind requirement in paragraph 3.2(c).

4.7 Humidity Test

The test is per MIL-STD-810F, Method 507.4, paragraph 4.5.2. The equipment is subjected to two complete cycles per Table 507.4-1, except the maximum chamber temperature is +55 degrees Celsius. Failure of the equipment to operate as specified is cause for rejection.

4.8 Salt Fog Test

The salt fog test is conducted per MIL-STD-810F, Method 509.4, paragraph 4.5.2. Failure of the equipment to operate as specified is cause for rejection. If corrosion is present, the third party certification body determines if it has impacted equipment structural integrity or functionality.

4.9 Sunshine Test

NOTE:  The manufacturer may submit a certificate of compliance (for consideration by the third party certification body) from the manufacturer attesting to UV resistance (per MIL-STD-810F) in lieu of the testing requirements below.

The equipment is in its normal operational configuration for this test.

A sunshine test is conducted per MIL-STD-810F, Method 505.4, paragraph 4.4.3, Procedure II for all obstruction lighting equipment with nonmetallic exterior parts or plastic/thermoplastic light covers.

The equipment is subjected to a minimum of 56 cycles.

An operational test of the equipment is performed after 56 cycles.

Any evidence of deterioration of plastic parts:  chalking, bleaching, cracking, hazing, or colour changes (yellowing) to the thermoplastic lenses of the test unit is cause for rejection.

For plastic/thermoplastic optical lenses or covers, the photometric performance is measured after this test.

4.10 System Operational Test

A system operational test is performed after the unit has been operated continuously without failure for 1000 hours with normal (12 hour) day/night cycling.

System components are connected with the necessary wiring to electrically simulate an actual installation in which the top and bottom light units on a structure are separated by 600 m for a system composed of CL-856 and/or CL-865 and 150 m for a system composed of CL-857 or CL–866, and the controller separated an additional 760 m. Simulated interconnecting cables with equivalent impedance may be used in lieu of full cable lengths.

The system is energized and operated to demonstrate compliance with all specification operating requirements such as flash rate, flash sequence, photoelectric switching of intensity steps, operation of interlocked devices, and satisfactory operation under input voltage variations.

If the power supply and optical head are separate components, it is demonstrated that with the maximum and minimum nameplate rated separation between components, proper energy is delivered to the light unit to produce the specified photometrics.

It is demonstrated that CL-810 and CL-864 lights produce the specified photometric requirement when energized over conductors (actual or simulated) representing the maximum and minimum nameplate rated cable length at the minimum input voltage.

APPENDIX C – Aeronautical Assessment Form for Obstruction Marking and Lighting
 

Figure 1-1: Lighting Terms

Figure 1-1: Lighting Terms

 

Figure 1-2: CL-180 Single and double Unit Lights

Figure 2-1: Shielding of Catenaries

Figure 2-2: Shielding Objects

Figure 3-1: Day Marking - Checkerboard Pattern>

Figure 3-2: Storage Tank Marking

Figure 3-3: Day Marking - Bended

Figure 3-4: Day Marking - Skeletal Structures (alternate bands)

Figure 4-1: Configuration of Lighting on Skeletal Structures

Figure 5-1: Red Lighting System, Light Levels Configuration "A"

Figure 5-2: Lighting positions for Tower Cross-Sections

Figure 5-3: Lighting of Prominant Buildings

Figure 5-4: Obstruction Lighting on Bridges

Figure 5-4: Obstruction Lighting on Bridges

Figure 6-1: Medium Intensity White Lighting System Configuration "D"

Fifure 7-1: High Intensity White Flasing System - Configuration "B"

Figure 7-2: Hyperbolic Cooling Tower

Figure 7-3: Lighting Adjacent Structures

Figure 7-4: Lighting Adjacent Structures

Figure 10-1: Catenary Markers

Figure 10-2: Catenary Flashing Lights

Figure 10-2b: Catenary Flashing Lights (with use of ADS)

Figure 10-3: Catenary Wire Lights

Figure 11-1: Marking and Lighting of Moored Balloons

Figure 12-1: Lighting - Wind farm and wind turbines (less than 150 m height)

Figure 13-1: Photometric Requirements

Figure 14-1: Colour Standard and Figure 14-2: Aviation Orange Colour Tolerance Chart

Figure 15-1: Catenary Crossing - plan view

Figure 15-2: Catenary Crossing - profile view

Figure 15-3: Potential Turning/descent Manoeuvres

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