Canberra ILS Multi-Cache
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Difficulty:
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Terrain:
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Size: 
(micro)
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This cache shows the features of the Canberra ILS (Instrument Landing System), which is used to guide aircraft to a safe landing at Canberra Airport. The Instrument Landing System normally consists of a "Localizer" for runway alignment guidance, a "Glide Path" for elevation guidance, and several "Marker Beacons" to provide key checkpoints along the approach. This multi-cache will bring you within sight of each of these components.
The Canberra ILS approach also uses a Non Directional Beacon (NDB) at Church Creek, south of the airport. This is not covered by this cache, but look out for the Traditional cache planted there!
At the first three waypoints you will find a tag that has two 5 digit numbers. The first is the S minutes, and the second is the E minutes for the next waypoint in the series.
These are all great places for a bit of plane watching!
WP1 - The Outer Marker
The Outer marker signals the start of the descent on the glidepath. The signal is transmitted vertically and when passed over, flashes a blue/purple light on the instrument panel.
The road can be busy here, so please take care parking in a safe spot
The Outer Marker
WP2 - The Middle Marker
The Middle marker signals that the 'Decision Height' has been reached. If the pilot cannot see the approach lights, runway lights or runway markings by this point, then the landing must be aborted. The signal is transmitted vertically and when passed over, flashes an amber light on the instrument panel.
This one is a bit harder to see, but from the WP you should be able to see a small white hut on the other side of the river.
The Middle Marker
WP3 - The Glide Path
The Glide Path (sometimes called the Glide Slope) produces two signals in the vertical plane. They are angled so that the intersecting point of the patterns indicates the descent angle (Usually 3 degrees). If the signals are equal, the aircraft is on the correct glide path. If not, an indicator will give a 'fly up' or 'fly down' signal.
The Glide Path
WP4 - The Localizer
The Localizer produces two signals in the horizontal plane. One signal is angled to the left of the runway, and the other to the right. If the signals are equal, the aircraft is on the centre line of the runway. If not, an indicator will give a 'fly left' or 'fly right' signal.
The cache is located at this waypoint. (Old tag removed)
The (old) Localizer. Now replaced with a shiny new red one
A typical approach to Canberra using the ILS would see an aircraft tracking towards the Church Creek NDB, and intercepting the localizer signal. This then provides the direction of travel. It then proceeds in level flight until it intercepts the Glide path signal at which point adjustments are made to descend along the glide path. Everything should be on track by the Outer marker, and the runway should be visible by the middle marker. Welcome to Canberra!
Disclaimer: I'm not a pilot, or an expert in this so things may not be 100% accurate, or may be overly simplistic (or plain wrong!).
The cache is a micro. Please replace as found. Stealth is often required near GZ - Pose as a plane watcher!
Additional Hints
(Decrypt)
JC1-Yrsg bs ybaryl fgnxr
JC2-Gbal'f Ivrj
JC3-Ohfu
JC4/TM-Tngr
Treasures
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