No idea, but one quiet day I did a practice ILS in a AS355 but when down to about 50' instead of hover taxying off to my hangar I actually hovered around the threshold and tried to see if I could actually find the 'sweet spot' on the runway where the ILS was aiming me.
There was no such point, it seemed to be around the 50 ' above the runway approx , after that it was actually impossible to react to the glideslope it was just hyper sensitve.
No doubt all the interfence lobes all bunch up that close to the sweetspot!!
come on techies, whats the real reason??
