OBST Abbreviation for: obstacle Fr: OBST
obstacle All fixed (whether temporary or permanent) and mobile objects, or parts thereof, that are located on an area intended for the surface movement of aircraft or that extend above a defined surface intended to protect aircraft in flight.
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abbreviation: OBST

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also called: obstruction

Fr: obstacle
obstacle clearance altitude The lowest altitude above the elevation of the relevant runway threshold or above the aerodrome elevation, as applicable, used in establishing compliance with appropriate obstacle clearance criteria.
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abbreviation: OCA

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see also : obstacle clearance height

Fr: altitude de franchissement d’obstacles
obstacle clearance height The lowest height above the elevation of the relevant runway threshold or above the aerodrome elevation, as applicable, used in establishing compliance with appropriate obstacle clearance criteria.
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abbreviation: OCH

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see also : obstacle clearance altitude

Fr: hauteur de franchissement d’obstacles
obstacle clearance limit The height above the aerodrome elevation below which the minimum prescribed vertical clearance cannot be maintained either on approach or in the event of a missed approach.
. abbreviation: OCL
Fr: hauteur limite de franchissement d’obstacles
obstacle light A light or one of a group of lights, usually red or white, frequently mounted on a surface structure or natural terrain to warn pilots of the presence of an obstacle. Fr: feu d’obstacle
obstruction Other expression for: obstacle (OBST)
OCA
(1) Abbreviation for: obstacle clearance altitude
Fr: OCA
(2) Abbreviation for: oceanic control area
Fr: OCA
oceanic control area
A controlled airspace extending upwards from specified limits over the high seas and over land.
. abbreviation: OCA
Fr: région de contr.le océanique
OCH Abbreviation for: obstacle clearance height Fr: OCH
OCL Abbreviation for: obstacle clearance limit Fr: OCL
off-route vector A vector provided by ATC that takes an aircraft off a previously assigned route. Altitudes assigned by ATC during such vectors provide the required obstacle clearance. Fr: vecteur hors route
offset parallel runways
Runways with parallel centrelines but thresholds that are not aligned.
Fr: pistes parallèles décalées
OM Abbreviation for: outer marker Fr: OM