Although the left-right course indications might look similar to those of a VOR, the localizer receiver becomes four times more sensitive when tuned to an ILS. That fact translates into ILS signal parameters that become tighter as the aircraft approaches the end of the runway, meaning the pilot must be prepared for smaller and smaller corrections to remain on course and on glideslope. It is the pilot’s task to learn the precise speed, rate of descent and aircraft configuration needed prior to intercepting the ILS that will allow the needles to remain crossed like a huge plus sign, indicating the aircraft is on the localizer course and on the glideslope. For instance, at the outer marker, normally 4 to 6 miles from the end of the runway, a one-dot deviation means the aircraft is about 500 feet off the centerline. Closer in, such as crossing the middle marker within a mile of the end of the runway, that same one-dot deflection translates into 150 feet off the centerline. At the middle marker, one dot high or low on the glideslope translates into flying 50 feet high or low.