ILS Systems

Instrument Pilot Course

• Components of and ILS 
• ILS Theory of Operation
• Cockpit Indication
• ILS Plan View
• ILS Profile View
• ILS Minimums
• LDA and SDF Approaches

ILS Components

• Localizer
• Glide Slope
• Marker Beacons
• Compass Locators
• Approach Lights
• Runway Markings

Localizer 

• Provides Left/Right Course guidance all the way to Miss approach 
• VHF Signal  - limited line of sight,  located at departure end of runway
• Last digit is always an ODD number eg 110.3 MHz
• 4 times more sensitive than VOR so full scale deflection on localizer mean pilot is 2 1/2 degrees off an ILS course

• Localizer is an antenna on the  emitting 2 beams of frequency .. left (yellow) one frequency and right (blue) a different frequency. 
• When pilot is center of both frequency (centred of runway) it will receive both frequencies equally
• When aircraft is to right it will only pick up one frequency and needle will deflect far right. 
• If aircraft picks up both frequencies then aircraft MUST be at the center of runway

Glide Slope

• Provides Vertical guidance all the way to the mis approach point in special cases all the way to touchdown
• Glide slope is NOT connected to the Localizer
• Separate signal from the side of the runway all the way upwards
• Uses UHF signal 
• Although not connected, the Glide slope frequency is paired with localizer frequency
• Glide slope frequency is NOT displayed to the pilot .. 

Marker Beacons

• Provides range information to airport 
• Outer marker allows for G/S Check
• Both Visual and Aural Indication
• Being phased out 
• 3 types of Marker Beacon - Outer, Middle, Inner 
• Pilot identify Marker Beacon by lights   Outer - Blue, Middle Yellow , Inner - White
• Pilot also identify Marker Beacon by Tone - Outer - long tone, Middle short longer tone at a quicker pace, Inner - very short tone rapidly

Compass Locator

• Substitutes for a marker beacon
• NDB Station
• Can be used to navigate to 
• Low power station
• Pilot needs an ADF Receiver in aircraft to use NDB

Approach Light System

• IFR to VFR Transition
• Provides lower visibility approaches
• Become part of the airport environment
• Runway Markings 

Plan View

• Top down view of the ILS 
• Shows course to fly and fixes
• Shows localizer frequency
• Shows terrain

Profile View

• shows altitude
• shows step down fixes
• shows G/S crossing height

Minimums

• Shows DA 
• Shows equipment failure altitudes
• show visibility requirements

Approach Termination

• Landing from the ILS
• Missed Approach

LDA and SDF Approaches

• Localizer directional type aid
• Not in line with the runway centerline
• Same accuracy as an localizer
• SDF - Simplified directional facility 
• Less accuracy than an localizer 
• May or may not align with runway centerline

https://www.youtube.com/watch?v=v8OyEWsTi1g#t=41.94182