However, there is a serious point within this post and that is that as visibility reduces, it may be necessary to reduce the operating height (sometimes below a safe level) to ensure that visual contact, ahead of the helicopter, can be maintained. This is necessary for two reasons: (1) to ensure that there are sufficient visual cues to maintain control; and, (2) to maintain spacial awareness. Both of these are important for an inexperienced pilot because they improve confidence and assure well-being.
I can agree to that.
I am still wanting to hear an explanation why the Sod Runway is invisible with a 1.5 km Visibility.
Pierre certainly drew a distinction between paved (assuming asphalt and not a light colored concrete surface) and grass.
A link to any Peer Reviewed Study would be acceptable....or even some sort of Technical Study that would confirm Grass becomes invisible somehow due to reduced visibility.