INTERMEDIATE FLIGHT PREPARATION WORKBOOK
Gulfport), then you will have to select the TACAN channel, the ILS frequency, and TCN/LOC.
VOR/LOC will give you ILS and ILS-DME information, TCN/LOC will give ILS and TACAN-
F104. MARKER BEACONS (FAN MARKERS)
Marker beacons are available with some ILS/localizer systems. Ordinarily there are 2 marker
beacons associated with an ILS: the Outer Marker (OM) and the Middle Marker (MM). The
OM always transmits at 400 Hz, and is indicated with an aural signal and an "OM" flashing on
the Attitude Directional Indicator (ADI) (or a flashing "blue" light on some aircraft). The OM is
collocated with the FAF and the approximate position for glideslope interception. The MM
always transmits at 1300 Hz, is collocated with the MAP or DH, and is indicated by an aural tone
and the "MM" flashing on the ADI (or a flashing "amber" light on some aircraft). Simply pull
the marker beacon knob(s) on the comm panel (see Dash-1, pg. 1-354) and make sure the volume
is at least halfway, no frequency input is necessary.
F105. COMPASS LOCATORS
A compass locator is a Nondirectional Beacon (NDB) used in conjunction with, or in place of a
MM and/or OM. They are tuned up on the ADF (see Mobile Regional ILS 14). You will need to
select the ADF on the bearing needle on the DSP. Upon station passage it will swing from 12 to
F106. TIMED ILS
As a backup, a timing box near the bottom of an approach plate will give the time required to
travel from the OM (FAF) to the MM (DH/MAP).
F107. SET UP
While initiating the "Approach brief" on the Descent Checklist, the ILS frequency should be
entered in NAV 1 and 2 (unless one of the NAVs need to be used for a radial to define the
OM/MM - see ILS 17 at Pensacola Regional. Saufley is used to define the FAF). Select
VOR/LOC or TCN/LOC (see Dash-1 pg. 1-194). Select the marker beacon (you can select 1 or 2
or both) and compass locator, if available. Zeroize your clock and be ready to start it passing the
OM/FAF. Initiate landing checks between 8-10 DME or between 1 to 2 dots below glideslope
(see Dash-1, pg. 1-174).
For more on the ILS/localizer system, refer to the AIM (a copy is located in the Ready Room).
Your instructor will brief and assist you with your first ILS approach, but you must still function
as a crewmember, so try to do as much as you can on your own. If you have any questions,
contact your PA, any T-1 instructor or P.
F-2 INSTRUMENT LANDING SYSTEM (ILS) BASIC