I I S Mode Selector is a device which changes the operational modes of
Integrated Instrument System.
I I S is the naviation system which provides HZ-4 Horizon Flight
Director, R-1 Indicator and C-6A Gyrocompass with the flight data
essential for safe conduct of flight.
Manual Pitch Trim (TRIM)
Manipulate (by click) the Trim Knob for fine adjustment of the Flight Director Pitch Bar,
which appears in HZ-4 Flight Director when FI, BL and VOR/LOC mode are selected.
(This knob has nothing to do with the aircraft trimming. Be cautious).
Selection of I I S Mode.
SB Mode (Stand By Mode)
Selection in SB mode changes FD into a standby status. At the left bottom corner of HZ-4 Flith
Director, the warning flag appears to indicate that the Flight Director are not functioning.
FD Pitch and Roll command bars are not displayed. R-1 indicates your position relative to the
VOR or ILS stations, tuned in to your NAV1 receiver. Bearings to the VOR of your NAV2 and NDB
station of your ADF are indicated on the C-6A Gyrocompass.
BL Mode (Blue Left Mode)
When BL mode is selected, the localizer signal is reversed when ILS signal has been received.
A motion of HZ-4 FD Roll command bar becomes reverse. BL mode are used only when ILS back
course approach is to be made. Pitch command bar of HZ-4 FD can be finely adjusted by the TRIM
knob of the IIS mode selector.
FI Mode (Flight Instrument Mode)
In this mode, be aware that motion of FD Pitch and Roll command bars are
related neither to the signal from VOR nor ILS. The commanded flight path
is based on pilot input to C-6A gyrocompass, and the pilot can manually fly
using the FD of FI mode. Pitch command bar of HZ-4 FD can be finely adjusted
by the TRIM knob of the IIS mode selector.
VOR/LOC Mode
When VOR/LOC mode is in use, a motion of HZ-4 FD Roll Command Bar is based
on the signal received from VOR or ILS tuned in to NAV1. Note that Pitch
Command bar will not be displayed even if ILS signal has been received.
APP Mode (Apporach Mode)
In this mode, a motion of HZ-4 Flight Director Pitch and Roll command bar
are based on the signal of ILS, both LOC and GP, tuned in to NAV1. This
APP mode shall be selected when you perform ILS approach.
GA Mode (Go Around Mode)
When GA mode is selected, HZ-4 Flight Director Pitch command bar are
automatically set to 7 deg pitch up, and Roll command bar are based
on pilot inputs to C-6A gyrocompass.