Part VIII - Air Navigation Services

Canadian Aviation Regulations (CARs) 2017-2

Standard 824 - Runway Visibility Assessment

Content last revised: 2006/12/01

(amended 2006/12/01; no previous version)

824.22 Interpretation

In these standards

“conversion table” means a table relating the number of visible runway edge lights to a distance in feet; (table de conversion)

“point of observation” means a fixed location near the threshold of the runway, such as the taxiway holding position for the taxiway adjoining the runway threshold, or at a point adjacent to the runway threshold, from which the distance to visibility markers is known. (point d’observation)


824.23 Visibility Markers

(1) Visibility markers are located as to be representative of the runway conditions.

(2) Visibility markers are located within 10 degrees of the runway centre line.

(3) Visibility markers consist of dark objects of suitable dimension, and of lights of moderate intensity.

Visibility Markers Chart

(4) A visibility markers chart includes:

(a) the visibility markers used to assess runway visibility, showing their distances in feet, and bearings from the point of observation;

(b) the identification of the day and night visibility markers in their proper positions by means of the designated symbols listed on the chart; and

(c) the clear identification of the point of observation.

(5) Runway edge lights are not indicated on the visibility markers chart.


The distance should be determined to the nearest 100 feet. Obstruction lights on towers and buildings and the various marker lights around an airport may be used for visibility markers.


824.25 Steps to assess runway visibility

(1) Runway edge lights may be used to assess the runway visibility.

(2) The aerodrome operator establishes a conversion table if runway edge lights are used to assess runway visibility.

(3) When runway edge lights are used to assess the runway visibility, the qualified person uses a conversion table to determine the distance assessed.

(4) A qualified person stands at the point of observation and, without using any optical devices to enhance their normal distance vision:

(a) assesses in the runway direction the farthest:

(i) visible runway edge lights; or

(ii) visibility markers that can be seen and identified;

(b) from the assessment in paragraph (a), determines the distance, in feet to the nearest 100 foot increment, using the conversion table or the visibility markers chart; and

(c) immediately reports the distance assessed, to the ATS facility that serves the aerodrome, if available, or to the person who requested the report, as the runway visibility along the specified runway in the following format:

RUNWAY VISIBILITY, RUNWAY [runway number] ASSESSED AS [distance assessed] FEET AT [time] UTC”, to the nearest 100 foot increment.


The term “optical devices” does not include spectacles or contact lenses that the qualified person usually wears for normal distance vision.

(5) If the runway visibility varies during the assessment, the qualified person reports the lowest value observed.

(6) The qualified person does not report any weather phenomena that is reducing the runway visibility unless the qualified person does so in accordance with section 804.01.


It is preferable that observations not be made through a window, especially at night.

Range of Values to be Reported

(7) The lowest limit of the reporting range of runway visibility is 200 feet.

(8) Where the runway visibility is below 200 feet, it is reported that the runway visibility is less than 200 feet.

(9) The upper limit of the reporting range of runway visibility is 6,000 feet.

(10) Where the runway visibility is above 6,000 feet, it is reported that the runway visibility is greater than 6,000 feet.

824.26 Qualifications and Training

The training to assess runway visibility ensures, at a minimum, that the qualified person

(a) can identify the location of each point of observation;

(b) can identify the visibility markers for each point of observation;

(c) can identify the runway edge lights;

(d) understands the use of the conversion table and the visibility markers chart;

(e) understands the format to be used to report runway visibility; and

(f) can review the steps to assess runway visibility.

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