Hey guys,
Does the visibility of every NPA need to be increased by 900m when the installed HAIL is not available, or only for the LOC?
ENR 1.5 p4.7.2 states quite clearly that it's only for the LOC, but I've had quite a few knowledgeable people maintain it's for all NPAs.
Cheers!
Yes, that reference does clearly state that, if HIAL is not available, the addition of the 900 m applies only to the LOC approach. It used to say that the 900 m applied to any 'runway aligned' approach, but that has now been changed to the LOC only.
It makes sense when you consider an NDB or VOR approach where the final approach track is not aligned with the runway. It wouldn't matter then whether the HIAL was working or not. In that case, the pilot's visual field at the missed approach point would not include the approach end of the runway.
Bob