Cessna 172P - Page 271

PILOT'S
OPERATING
HANDBOOK
SUPPLEMENT
12
FOSTER,
AREA NAVIGATION
(TYPE
õ11)
õ11)
consists
of
a
recaiver,
a DME
SUPPLEMENT
FOSTER
AREA
NAVIGATION
SYSTEM
'(rro"
s11l
sEcTloN
I
GENERAL
The
Foster Area
Navigation System
(RNAV
-
Type
õ11 A¡ea
Nav
Computer, a compatible VHF
navigation
Adapter
Module
and DME.
The RNAV 511 is a basic Area Navigation Computer
with
two
thumb-
wheel
programma,ble
waypoints.
It
performs
oontinuous
computation
of
triangulation
probloms.
The
VOR and DME
oquipment
in the aircraft
provides
information
to
the
computer
on aircraft
position
relatlve
to the VORTAC
statlon.
A
waypoint ls dialed into
one set of waypoint
t'humbwheels
by
inserting
the
R ADIAL and DISTANCE
of the waypoiat
(the
position
the
pilot
would
like
to
fly over,
or
to) relative
to tbe VORTAC station.
The RNAV
õll computer
calculates the
Magnetic Bearing
(BEARING)
and Distanoe
(RANGE
NM)
from the
aircraft to the
waypoint
repeatedly to
provide
continual
informa-
tion on WHICH
\t¡AY
aud HO\ry FAR
to the waypoint.
The
pilot
can
monitor BEARING and
RANGE on RNAV
õ11
to fly
straight
line
patbs
to waypoints up to 200 NM distance
from tJre aircraft
position.
Waypoints
can be
precisely
dialed
into the thumbwheels
to
0.1o
and 0.1 NM resolution.
The RNAV 511 also
provides
immediato
positiou
oriontation
relative
to
the
VORTAC
(VOR/DME)
station belug used
for computation.
Merety
press
the
VOR,/DME
pushbutton
to diaplay
the RADIAL
and DME
distance
from the VORTAC.
Another feature
of the
RNAV õ11 is its
abilÍty
to
provide
evidence of
proper
computatiou
in the
system.
The system can be
tested
at anytime
before
fiight
or while
airborne
to
confirm
proper
computer
operation.
An
acceptable "test"
is
evidenoed
by
the
actÍve
waypoint's
RADIAL/DIST-
ANCE being
displayed
in
tbe BEARING
and RANGE
wiudows of
the
RNAV õ11
while TEST
pushbutton
is
pressed.
In addition
to
the
"teet"
feature, diagnostlc
functions
are
provided
to alert the
pilot
of why the
system
is
not
functional.
30 May 1980
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