Limited Obstacle Sector (LOS)
Limited obstacle sector (LOS) is a sector extending outward which is formed by that portion of the 360° arc, excluding the obstacle-free sector, the centre of which is the reference point from which the obstacle-free sector is determined. Obstacles within the limited obstacle sector are limited to specified heights.
Source: IMO Resolution A.1023(26), Code for the Construction and Equipment of Mobile Offshore Drilling Units (2009 MODU Code), 2009. Global Standards
Limited Obstacle Sector, the 150° sector within which obstacles may be permitted.
Source: NOGEPA Guideline 14, Helideck Operations and Procedures Manual, Netherlands, Version 2, December 2011. Global Standards