Distance measuring equipment (DME)

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

Components and Characteristics of the Instrument Landing System (ILS)

(2) indicates a position approximately 3,500 ft from the landing

threshold and approximately 200 ft AGL above the

touchdown zone

(3) Identification is a coded audio tone (dot dash dot dash) and

flashing amber cockpit marker light

Inner Marker (IM)

(1) Indicates a point that an aircraft flying a Category II or III

ILS approach is at the designated decision height (DH) on

glidepath between the MM and the touchdown zone

(2) Aircraft is approximately 100 ft AGL at IM if on glidepath

and FAC

(3) Identified by a coded audio tone (four dots) and a flashing

white cockpit marker beacon light

d. Back Course (BC)

Sg 3, fr 8

Back Course LOC (FAF)

(1) A BC marker beacon normally indicates a LOC BC final

approach fix (FAF) where the approach glideslope is

intercepted and the descent is commenced

(2) Identified by a coded audio tone (two dots) and a flashing

white cockpit marker light

5. Marker beacon tones

Sg 3, fr 9

a. Marker beacons emit specific coded tones, at different pitches,

Fig 3: Marker Beacon

which the pilot of an ILS/LOC equipped aircraft can monitor

Code/Color Identification

when on the final approach course

Table

b. In the T-45C, marker beacon tones may be monitored by

placing the “MKR” switch on the communications control panel

to the “ON” position

MKR audio tone volume in the T-45C is preset and cannot be

controlled by the RCVR volume control knob on the

communication control panel

B. Distance measuring equipment (DME)

Sg 3, fr 15

1. When DME is specified in the approach procedure, DME may be

DME

used:

a. In lieu of the OM

b. As a BC final approach fix (FAF)

To establish other fixes on the localizer course

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