The ILS Hud
In nearly 60 years of use in the real world, ILS systems were never found at fault in an airplane Crash. This flawless record, think about what it can do Second Life aviation. The ILS usually consists of a Localizer, Glide Path, and Markers (OM, MM, & IM). This instrument created for Second Life also includes Non-directional Beacon Indicator (NDB).
Localizer: This equipment provides lateral guidance to the runway centerline in regions along the approach path.
Glide Slope: This equipment provides the aircraft with a glide angle - 5 degrees, which may feel very shallow to those unaccustomed to flying a correct ILS approach, but consider glide slopes in real life are -3 degrees. The Localizer and Glide Slope combine to bring the aircraft to a point where the aircraft is about 10 feet high at the runway threshold (decision point). A pilot can fly effectively "blind" using instruments only, with ILS and Second Life's Map (which acts like GPS).
1. The Outer Marker is at approximately 256 meters or the one full region away from runway threshold. Altitude of aircraft should be approximately 100 feet in the Second Life simulation.
2. The Middle Marker is approximately the halfway point between outer marker and runway threshold. Altitude will be approximately 50 feet, in the glide slope.
3. The Inner Maker is about forty meters from Runway threshold and the runway should be coming into view, if flying in fog or low draw distance. This is the decision point for trimming your aircraft for landing.
Non-Directional Beacon (NDB):
It points to a radio transmitter no matter where you are. The needle indicates the direction to get to the transmitter on a straight line.
The Illustration above shows the ILS. The vertical needle is the localizer; the horizontal needle is the glide slope. The dots represent the center of the ILS or distance from center of ILS. The round button is the airport selector. Below the instrument are the marker indicators. Vital runway information is displayed beside instrument in floating text.
Practical use of ILS in Second Life:
This ILS was designed with the intention of pilots to be able to line up for a runway and enter glide slope as many regions away from the runway as pilot wishes. I prefer to prepare my aircraft for landing two regions away or more from runway (at least 500 meters).
First, I turn to approach heading while lining up my aircraft laterally by centering localizer needle and at the same time, adjusting direction to bring the NDB indicator to top center. Your goal is achieved when the localizer and NDB indicator is lined up dead center. NDB, direction to be indicated by the yellow triangles rotating around the outer dial, the little yellow triangle with the yellow extended yellow line is the "direction to" or "heading.” You want your heading to be the same as runway direction. If so equipped, autopilot is a great aid for correcting your course during procedure of lining up, and holding course after.
Next thing I observe the glide slope needle and begin adjusting my rate of descent, making use of combined flaps, throttle, and pitch. If the glide slope needle were low (lower than the first dot under the horizon), this means I am flying higher then glide path and I would take steps to loose altitude. If the needle below the horizon, the opposite is true. Once I enter glide path, I adjust aircraft's pitch to nose up, set flaps, and throttle back, maintain glide path. Glide path or glide slope. The glide path is loosely defined as being between the first dot underneath the horizon to the horizon itself. Being with in this range will being you to correct altitude when crossing runway threshold, and allow you to initiate a landing on the threshold or little beyond. I recommend not maintaining a glide path where the cross hairs are directly on horizon, for you may touch down short of runway. It is best to have glide slope needle somewhere between horizon and the dot directly under it. Landing gear down can affect glide path, so it is wise to lower them early in planning your approach.
Here are a few videos of the ILS in operation.