A visual alignment guidance system should be provided to serve the approach to a heliport where one or more of the following conditions exist especially at night: a) obstacle clearance, noise abatement or traffic control procedures require a particular direction to be flown; b) the environment of the heliport provides few visual surface cues; and c) it is physically impracticable to install an approach lighting system.
Online Language Learning Tool SkELL allows users to search for phrases in sentences, collocates and similar words. These examples have been automatically selected and may contain errors.
