Document ID: chunk:federal_register_of_legislation:F2024C01244:front:0:p41
Version: federal_register_of_legislation:F2024C01244
Segment Type: other
Provision Reference: 
Character Range: 135800–138682

normal aircraft operations are not disrupted and the movement area can be restored to normal safety standards in not more than 30 minutes.

touchdown zone means the portion of a runway, beyond the threshold, where landing aeroplanes are to first contact the runway.

traffic density has the same meaning as aerodrome traffic density.

transient obstacle includes a mobile obstacle.

T-VASIS means T visual approach slope indicator system.

Type A chart is a chart which contains information on all significant obstacles within the take-off area of an aerodrome up to 10 km from the end of the runway.

Type B chart is an obstacle chart which provides obstacle data from around the aerodrome.

UHF means the ultra high frequency band, that is radio frequencies in the range 300 to 3 000 MHz.

UNICOM (universal communications) means a non-air traffic control communication facility operated to provide an advisory service to enhance the value of information normally available at a non-controlled aerodrome.

unsealed, for a surface, means that the surface is not sealed.

VASI means visual approach slope indicator.

VASIS means a visual approach slope indicator system.

VDB means VHF data broadcast.

VDGS means a visual docking guidance system.

VFR means visual flight rules, and has the same meaning as that given in CAR for V.F.R.

VHF means the very high frequency band, that is radio frequencies in the range 30 to 300 MHz.

visibility (V) means visibility for aeronautical purposes and is the greater of the following:

(a) the greatest distance at which a black object of suitable dimensions, situated near the ground, can be seen and recognised when observed against a bright background;

(b) the greatest distance at which lights in the vicinity of 1 000 candelas (cd) can be seen and identified against an unlit background.

Note 1   The 2 distances have different values in air of a given extinction coefficient, and the distance mentioned in paragraph (b) varies with the background illumination. The distance mentioned in paragraph (a) is represented by the meteorological optical range (MOR).

Note 2   For international recognition and consistency, the definition of visibility is taken from ICAO Annex 3, Meteorological Service for International Air Navigation, Chapter 1, Part 1. For ICAO documents, see section 1.07.

visibility marker means a dark object of suitable dimensions for use as a reference in evaluating runway visibility.

visual aids means visual aids to navigation in the form of markers, markings, lights, signs, signals, displays or wind direction indicators, or combinations of these, which provide information to aircraft and vehicles on, or using, the movement area of an aerodrome.

visual meteorological conditions (VMC) means meteorological conditions expressed in terms of visibility, distance from cloud, and ceiling, equal to or better