Cessna 172P - Page 347

22
PILOT'S OPEN,AIING
HANDBOOK
CESSNA
4OO
TR,ANSPONDER
SUPPLEMENT
.â,ND
ALTITUDE
ENCODER,
(BLTND)
SUPPLEMENT
GESSNA
4OO TRANSPONDER
(Type
RT-45941
AND
oPTIoNAL
ALTITUDE
ENCODER
(BLIND)
SECTION
1
GENERAL
The
Cessna
4OO
Transponder
(Type
F,T-4594), shown
in Figure
1, is the
airborne component of an
Air Traffic Control
Radar Beacon
System
(ATCRBS).
The transponder enables
the ATC
ground
controller
to
"see"
and identify the aircraft, while in
fligbt, on the control center's
rad&rscope
more readily.
The
Cessna
4OO
T¡ansponder
system consists of a
panel-mounted
unit
and an externally mounted antenna,
The transponder receives interrogat-
ing
pulse
signals on 1030 MHz and transmits
pulse-train
reply signals
orr
1090 MHz.
The transponder
is capable of replying to
Mode ,{
(aircraft
identification)
and also to Mode C
(altitude
reporting) when coupled
to an
optional
altitude encoder system. The transponder
is capable of
replying
on both
modes of intorrogation on
a selective
reply
basis on any of 4,096
information
code selections.
The
optional
altitude encoder system
(not
part
of a standard
4OO
Transponder system) required for
Mode
C
(altitude
reporting)
operation,
consists
of a completely
independent remote-
mounted
digitizer that is connected
to
the static system and supplies
encoded
altitude intormation to the
transponder.
When the
altitude encoder
system
is coupled to the
400 lransponder system, altitude reporting
capabilities
are
available
in 1Q0-foot increments between
-1000
feet and
the
airplane's
maximum
servioe
ceiling,
AU
Cessna
400
Transponder
operating controls are
located
on the
front
panel
of
the unit. Functions of the operating controls
are
described in
Figure
1.
30 May
1980
l
of
6