仪表飞行员地面课程Lesson 5.ppt

Sierra Academy of Aeronautics IR Ground Lesson 5 Precision Approachs Precision Approaches Provide lateral and vertical guidance Examples: ILS, MLS, and PAR Instrument Landing System (ILS) Basic Ground Components of the ILS: Localizer Glide Slope Outer Marker Middle Marker (Approach Light System) Localizer VHF ground based transmitter that provides course guidance to the runway centerline. Angular width of course varies between 3 and 6 degrees. Course width at runway threshold is approximately 700 feet. Localizer sensitivity is 4 times greater then VOR. Localizer (cont.) Localizer reception is available to at least 18NM from antenna and up to an altitude of 4,500 ft. above the antenna. Localizer (cont.) Each dot represents ? degree off course. 40 ILS channels: 108.10 – 111.95 MHz (odd ths) Four-letter Morse code Localizer Orientation: Signal only represents one magnetic course to runway. OBS DOES NOT affect course tracking. TO Flag present regardless of inbound/outbound, front course/back course. When tracking in same direction of front course, proper sensing; when tracking opposite direction of front course, reverse sensing occurs. (179 vs. 359) When using HSI, must twist in front course to allow continuous proper sensing. Localizer Orientation: Glide Slope UHF transmitter is “paired” to the VHF localizer frequency. Provides vertical guidance to a distance of 10 NM. Signal is only 1.4 deg. thick, so extremely sensitive. Should intercept GS at recommended published altitude to avoid false GS indications. ILS Marker Beacons Provide range information and indicate significant points in the approach. ILS Marker Beacons (cont.) Outer Marker (OM) Placed at FAF for the nonprecision approach/just inside point of glide slope intercept (4-7 miles from runway threshold). Glide slope is approximately 1,400 feet above OM. ILS Marker Beacons (cont.) Middle Marker (MM) Located approximately 3,500 feet from runway threshold and intercepts glide slope at approximately 200 feet abo