仪表飞行员地面课程Lesson 12.ppt

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 above TDZE. This usually corresponds with DA, however MM is not a MAP! ILS Marker Beacons (cont.) Inner Marker (IM) Located between MM and runway threshold and indicates where glide slope should intercept decision height for a CAT II approach. Back Course Marker (BCM) Located 4-7 miles from opposite end of runway and serves as FAF for back course approach. * Only OM is required for the CAT I ILS. Inoperative ILS Components Glide Slope Use Localizer minimums. Becomes nonprecision approach. Localizer OTS ILS approach not authorized. Outer Marker OTS ILS approach not authorized without approved substitute. Approach Lights OTS ILS approach authorized, however refer to INOP Components Table to determine adjustments to visibility requirements. Substitutions for Outer Marker Compass Locator Precision Approach Radar (PAR) Approach Surveillance Radar (ASR) Published DME fix Published VOR fix Published NDB fix Substitutions for Middle Marker: Compass Locator Precision Approach Radar (PAR) Variations from typical ILS approach CAT I, CAT II, CAT III Special equipment, training and certification? Localizer-Type Directional Aid (LDA) Same frequency range, accuracy, and dimensions May have glide slope, but not aligned with runway centerline Variations from typica