WDL
As a WDL on an offshore installation obviously is considered as a condition which may be hazardous, I am very much in favour of the status lights as described in CAP 437:
Ch 2.3.5 : NOTE: The installation of ‘Status Lights’ systems (see Chapter 4, paragraph 3.6) is not considered to be a solution to all potential flight safety issues arising from hydrocarbon gas emissions; these lights are only a visual warning that the helideck is in an unsafe condition for helicopter operations.
Ch 4.3.6: A visual warning system should be installed if a condition can exist on an installation which may be hazardous for the helicopter or its occupants. The system (Status Lights) should be a flashing red light (or lights), visible to the pilot from any direction of approach and on any landing heading. The aeronautical meaning of a flashing red light is either “do not land, aerodrome not available for landing” or “move clear of landing area”. The system should be automatically initiated at the appropriate hazard level (e.g. impending gas release) as well as being capable of manual activation by the HLO. It should be visible at a range in excess of the distance at which the helicopter may be endangered or may be commencing a visual approach. CAA Paper 2008/01 provides a specification for a status light system which is summarised below:......etc.
Regards
Dommer