Visual Information System

T-45C TS INav-04; ADV INav-02

Components and Characteristics of the Instrument Landing System (ILS)

III. Visual Information System 2.9.5.5.1

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Approach lights

Fig 4: Instrument Runway

Lighting

Runway centerline lights

Touchdown zone lights

Runway lights

A. Approach Lighting System (ALS)

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Approach Lighting System

1. Provides main visual system used to transition from instrument

flight to visual flight for landing

2. Precision approaches, such as the ILS approach, require the

configuration of the ALS to start at the landing threshold and to

extend into the approach area for a distance of 2,400 to 3,000 ft

3. Non-precision approach runway lights would only run 1,400 to

1,500 ft from runway threshold

4. Some ALS use sequenced lights running toward the runway at high

speed (twice a second). These lights are Runway Alignment

Indicator Lights (RAILs) more commonly referred to as “rabbit

lights”

NOTE: The example of approach lighting systems provided in this

lesson is not unique. Examples of each configuration and publication

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identification code can be found in the Flight Information Handbook.

Flight Information

Additionally, the code identifying the type of ALS for an approach to a

Handbook, FLIP Approach

Plates

given runway is provided on the bottom right corner of the instrument

approach plate in the airfield layout box.

B. Runway Centerline Lights (RCLs) and Touchdown Zone Lights (TDZLs)

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RCLs, TDZLs

1. RCLs and TDZLs are a category of lighting known as “in-runway

lights”

2. RCLs

a. Inset flush into the runway

b. Spaced at 50-ft intervals beginning 75 ft from the landing

threshold and extending within 75 ft of the opposite end

White until the last 3,000 ft of runway. From 3,000 ft to 1,000 ft

from end of runway, the lights alternate red and white. The last

1,000 ft they are all red

5. TDZLs

a. Incorporate two rows of transverse light bars disposed

symmetrically about the runway centerline in the runway

touchdown zone

(2-02) Original

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