Obstacle Limitation Surfaces Survey

HELIDECK - OBSTACLE LIMITATION SURFACES A heliport located on a fixed or floating offshore facility such as an exploration and/or production unit used for the exploitation of oil or gas.  Shipboard heliport. A heliport located on a ship that may be purpose or non-purpose-built. A purpose-built shipboard heliport is one designed specifically for helicopter operations. A nonpurpose-built shipboard heliport is one that utilizes an area of the ship that is capable of supporting a helicopter but not designed specifically for that task.  Winching area. An area provided for the transfer by helicopter of personnel or stores to or from a ship. For helidecks that have a 1 D or larger FATO it is presumed that the FATO and the TLOF will always occupy the same space and have the same load bearing characteristics so as to be coincidental. For helidecks that are less than 1 D, the reduction in size is only applied to the TLOF which is a load bearing area. In this case, the FATO remains at 1 D but the

  These Obstacle Limitation Surfaces (OLS) “define the airspace around aerodromes to be maintained free from obstacles so as to permit the intended aeroplane operations at the aerodromes to be conducted safely and to prevent the aerodromes from becoming unusable by the growth of obstacles around the aerodromes.” Obstacle Limitation Surfaces   Assumes that the aircraft is operating normally   Provides volumes of airspace around and above an airport for an aircraft in normal flight Obstacle: All fixed (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 fight Obstacle Limitation Surfaces Eight Obstacle Limitation Surfaces:  • Conical Surface  • Inner Horizontal Surface  • Approach Surface  • Inner Approach Surface  • Transitional Surface  • Inner Transitional Surface  • Balked Landing Surface  • Take-off Climb IMAGINARY SURFACES FOR OB