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6-1
This is the last chapter on the operation of the KLN 90B.
In this chapter you will learn how to use the KLN 90B for
non-precision approaches as well as SID/STAR proce-
dures. All of these procedures require that you are com-
fortable with the operation of the unit as presented up to
this point. In particular, you need to be comfortable with
flight plan operation (chapter 4) and the OBS mode
(section 5.9).
Rev 1
CHAPTER 6 - LEVEL 4 OPERATION
6.1 NON-PRECISION APPROACH
OPERATIONS
Flying non-precision approaches using the KLN 90B are
not in themselves very difficult. However, it is different
than using traditional equipment such as VORs and
NDBs. With this in mind, make sure that you practice
with the KLN 90B in VFR weather with a check pilot
before attempting to use the KLN 90B in actual IFR condi-
tions.
CAUTION: The KLN 90B obtains approach informa-
tion from the database. Therefore, it is extremely
important that the database is current. The KLN 90B
is approved for IFR non-precision approaches only
when the database is current. If you attempt to select
an approach when the database is out of date, you
will be given the status-line message: “OUTDATED
DB” in the bottom center portion of the screen as a
reminder.
The following sections assume that your KLN 90B is
properly installed in the aircraft with all of the necessary
accessories to fly non-precision approaches. In most
cases this will mean that the aircraft has external
switch/annunciators to arm the approach mode and to
select the LEG or OBS modes. An external annunciator
to indicate when a message is active and when waypoint
sequencing is about to occur will also be installed. In
some installations the aircraft will have a NAV/GPS
switch to select which navigation source is displayed on
the primary HSI or CDI.
The Super NAV 5 page has been specifically designed to
provide most of the functions needed for non-precision
approaches. This page provides an interface that pre-
sents pertinent navigation information, a way to access
the flight plan, and a graphic presentation of the present
position relative to the flight plan waypoints. You will find
this page to be a good friend while performing GPS
based non-precision approaches.
NOTE: There are some approach procedures in the
world that are not suited for the operational characteris-
tics of the KLN 90B. These procedures are not included
in the database. Therefore it is not possible to use the
KLN 90B for these approaches. It is good preflight prac-
tice ensure that the KLN 90B contains anticipated proce-
dures for the flight.
In addition to the two course modes (Leg and OBS)
described in section 5.9, there are also two approach
modes. These are approach arm and approach active.
The status of the approach mode is indicated both on an
external switch/annunciator and on the status line of the
KLN 90B. In most installations the external annunciator
will indicate ARMfor the approach arm mode and
approach active will be annunciated by ACTV. The main
difference of these modes from the normal enroute mode
is that the integrity monitoring is set to a tighter level.
Another difference between these modes and the enroute
mode is that 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.
The ARM mode can be selected in two ways. The nor-
mal way is that this mode will be selected automatically
by the KLN 90B when the aircraft is within 30 NM of an
airport and an approach is loaded in the flight plan for that
airport. It is possible to arm the approach mode at a dis-
tance greater than 30 NM from the airport by pressing the
external GPS approach 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, then the KLN 90B will
disarm the approach and change back to enroute mode.
The CDI scale factor will also change back to ±5.0 NM.
The approach can be re-armed by simply pressing the
GPS APR switch again.
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.