Becker BXP6401-1 Series, Installation And Operational Manual

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H. Flight operation in Mode A/C/S (reply code and altitude code)
(1) When ATC requests the transmission “squawk”, switch the transponder
to ALT using mode switch (A).
NOTES: This only makes sense if the transponder is connected to a
coding altimeter. If not, tell ATC that you do not have mode C
(“mode charlie not available”).
In exceptions the altitude has to be turned off, i.e. switch the
transponder to ON using mode switch (A).
(2) The transponder replies using the selected Code and in response to
mode C interrogation it transmits the altitude of the aircraft to ATC. A
“R” on the left next to the Code on the display signals the transponder
replies.
NOTE : Switch the transponder to Stand-by (SBY), if the Code has to
be changed. Otherwise if could happen that a Code with a
special meaning (see chapter K, e.g. highjack) will be trans-
mitted and unwanted actions could take place.
(3) After a “squawk ident” request from ATC, press Ident button IDT (D)
briefly. This transmits an additional special pulse (SPI) for approx. 18
seconds, which enables the aircraft to be clearly identified on the radar
screen of the controller. “ID” appears on the left side in the LC dis-
play during this time.
(4) In a normal installation the blind encoder is only powered if the trans-
ponder is not switched OFF (at least SBY).
A blind encoder needs a warm-up time (sometimes several minutes).
Therefore, although the solid state transponder needs no warm-up time,
turn the transponder to SBY immediately after starting the engine.
INSTALLATION AND OPERATION BXP6401-X-(XX)
Page 3-8
34-50-08
September 2011