Correct Answer - Option 2 : Decision height
Decision height: The lowest height above the runway where the pilots make the decision to continue the landing manoeuvre or to cut is short is called the decision height.
Threshold height: The theoretical height above the runway threshold at which the aircraft's glideslope antenna would be if the aircraft maintained the trajectory established by the mean ILS glideslope or MLS glide path.
Runway visual range: The runway visual range (RVR) is the distance over which a pilot of an aircraft on the centreline of the runway can see the runway surface markings delineating the runway or identifying its centre line. RVR is normally expressed in feet or meters.
Important points:
The height of the pilot's eye above the runway surface is assumed as 3 meters.
The height of the driver’s eye above the road surface is assumed as 1.2 meters.
Eye’s level of the driver/pilot is very essential factor in deciding the various geometric design factor for highway and runway respectively.
