11/27/2022 0 Comments Localizer ilsThe transmitting glideslope antenna is located off to the side of the approach runway approximately 1,000 feet from the threshold. Radio signals funnel the aircraft down to the touchdown point on the runway at an angle of approximately 3°. The vertical guidance required for an aircraft to descend for a landing is provided by the glideslope of the ILS. The pilot must turn toward the right to center the CDI and the aircraft with the runway center line. If the 90 Hz signal is received by the VOR receiver, the CDI deflects to the right. This centers course deviation indicator on the display and centers the aircraft with the centerline of the runway. The pilot must correct course with a turn to the left. This indicates that the runway is to the left. If the aircraft receives a 150 Hz signal, the CDI of the VOR/ILS display deflects to the left. The signals received are passed through filters and rectified into DC to drive the course deviation indicator. The circuitry specific to standard VOR reception is inactive while the receiver uses localizer circuitry and components common to both. The aircraft’s VOR receiver is tuned to the localizer VHF frequency that can be found on published approach plates and aeronautical charts. The right side of the approach contains a 150 MHz modulated signal. The left side of the approach area is filled with a VHF carrier wave modulated with a 90 Hz signal. The field tapers to runway width near the landing threshold. They create an expanding field that is 21⁄2° wide (about 1,500 feet) 5 miles from the runway. Two modulated signals are produced from a horizontally polarized antenna complex beyond the far end of the approach runway. The localizer broadcast is a VHF broadcast in the lower range of the VOR frequencies (108 MHz–111.95 MHz) on odd frequencies only. Components of an instrument landing system (ILS). Together, all of these radio signals make an ILS a very accurate and reliable means for landing aircraft. Marker beacons provide distancefrom- the-runway information. Compass locator transmissions for outer and middle approach marker beacons aid the pilot in intercepting the approach navigational aid system. A separate glideslope broadcast provides vertical guidance of the aircraft down the proper slope to the touch down point. It is used to provide horizontal guidance to the center line of the runway. A localizer is one of the radio transmissions. Multiple radio transmissions are used that enable an exact approach to landing with an ILS. This radio navigation system guides the aircraft down a slope to the touch down area on the runway. An ILS is used to land an aircraft when visibility is poor.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |