h. Changing the CDI Scale Factor. The CDI
scale factor can be changed by using either the MOD
1 or MOD 2 pages. In normal operation, it is possible
to select a CDI scale factor that is ± 5 nm, 1 nm, or
0.3 nm full-scale defection.
The KLN 90B will automatically select a
scale factor while in one of the approach
modes. When the KLN 90B selects a CDI
scale factor, it is not possible to select a
scale factor that is less sensitive.
1. Select either the MOD 1 or MOD 2 page.
2. Press the left CRSR button. If necessary,
use the left outer knob to move the cursor
over the value of the CDI scale.
3. Rotate the left inner knob to select the
desired scale factor.
4. Turn the left cursor function off.
3D-21. APPROACH OPERATIONS.
a. Non-Precision Approach Operations. The
message/waypoint annunciator, is the primary navaid
selector to select which navigation source is displayed
on the pilot's EHSI, the course mode selector/
annunciator, to select the LEG or OBS modes, and the
approach mode selector/annunciator, to arm and
annunciate the approach modes, must be operational.
The KLN 90B obtains approach information
important that the database is current. The
KLN 90B is approved for IFR non-precision
approaches only when the database is
current. If an approach is selected when
the database is out of date, a status line
display in the bottom center of the screen.
(1) The Super NAV 5 page has been
specifically designed to provide most of the functions
needed for non-precision approaches. This page
navigation information, a way to access the flight plan,
and a graphic presentation of the present position
relative to the flight plan waypoints.
There are some approach procedures that
characteristics of the KLN 90B. These
database. Ensure that the KLN 90B
contains anticipated procedures for the
(2) In addition to the LEG and OBS course
modes, there are also two approach modes. These
are approach arm and approach active. The status of
the approach mode is indicated both on the external
switch/annunciator and on the status line of the
KLN-90B. The external annunciator will indicate ARM
for the approach arm mode and approach active will
be annunciated by ACTV. The main difference
between these modes from the normal en route mode
is that the integrity monitoring is set to a tighter level.
Another difference between these modes and the en
route modes is the CDI scale factor will usually change
to ± 1.0 nm for ARM and will always change to
± 0.3 nm when in the APR ACTV mode.
(3) The ARM mode can be selected in two
ways. The normal way is that this mode will be
selected automatically by the KLN 90B when the
aircraft is within 30 nm of the destination airport and an
approach for that airport has been loaded in the flight
plan. It is possible to arm the approach mode at a
distance greater than 30 nm from the airport by
pressing the GPS APR switch, but the KLN 90B will
not change the CDI scale factor until the aircraft
reaches the 30-nm point. If the GPS APR external
switch is pressed while the approach mode is armed,
the KLN 90B will disarm the approach and change
back to en route mode. The CDI scale factor will also
change back to ± 5.0 nm. The approach can be
rearmed by simply pressing the GPS APR switch
(4) The APR ACTV mode can only be
engaged automatically by the KLN 90B. To cancel the
APR ACTV mode, press the external GPS APR
switch. This will change the mode to APR ARM.
Once past the FAF, it is not possible to return to the
approach active mode without conducting a missed
approach and flying back to the FAF.
b. General Procedures for Non-Precision
Approaches. Non-precision approaches will all have
the same general flow. Refer to Figure 3D-56.