11
TRANSPONDER
The aircraft is equipped with a Microair Avionics T2000SFL transponder. Operation of the
transponder is outlined below
CONTROLS -
1 ON Key
2 MODE Key
3 ENTER Key
4 IDENT Key
5 TOGGLE Key
6 CODE SELECT Knob
7 SELECTMODE Knob
8 VFR Key
TRANSPONDER OPERATION
The tranpsonder can be operated in the following modes:
ON
Mode A where only the active code is sent
ALT
Mode C where both the active code and altitude is sent
If requested by ATC the user can squawk ident (ID Key). The display can present the active
and standby codes. The standby code can be changed at any time and then toggled to
become the active code. The T2000 can replace the standby code in the display with the
encoder altitude or supply voltage. The SFL is a dual line display of 8 characters each, with
the active code on the top line, and the standby code on the bottom. The display is LCD, with
preset backlighting.
When the altitude is displayed, the standby code is saved into memory. To display the
standby code again, press the toggle key once to make it appear on the bottom line. Press the
toggle key again to exchange the active and standby codes. After 10 seconds of inactivity, the
lower line will revert to displaying the altitude. Pressure Altitude (PA) is the Encoder altitude.
The encoder's barometric adjustment is preset to 1013 millibars (29.92HG). If the Encoder is
not powered or not fitted, the message NO ALT will appear on the display. It is possible to
input the QNH/Baro (barometric pressure) given by ATC, into the T2000 to adjust the
displayed pressure altitude. This feature will allow the user to adjust the displayed altitude to
read the same as the aircraft's altimeter. The T2000 will transmit the encoder altitude
(pressure altitude) only, in accordance with normal mode C operation. The adjusted QNH/Baro
altitude is never transmitted.
ON KEY
TURNING ON
The T2000 is turned on by pressing the ON key. The T2000 will go through a
start up routine displaying self-test messages, and ending with the operational display.
BACKLIGHTING
The T2000SFL has an LCD display which is backlit. The backlighting has a
low and a high brightness level to enhance the display in low light conditions. When the T2000
is first turned on there is no backlighting. Pressing the ON key multiple times cycles through
the low level backlighting to high level backlighting to no backlighting
TURNING OFF
The T2000 is turned off by holding down the ON Key. The word SHUT DOWN
is displayed and the T2000 counts down from 3, then turns off. If the ON Key is lifted before
the count is finished, the T2000 returns to the operational screen.
MODE KEY
The MODE key can be used to access two separate menus:
If the transponder is turned OFF, by holding down the MODE key, and pressing the
ON key the T2000 will start in PROGRAM MODE. The MODE key must be held
down, until the start-up self-test messages have been displayed.
If the transponder is ON and in normal operation, press the MODE key to access
the MODE MENU The first item of the MODE MENU is displayed. Step through the
MODE MENU by pressing the MODE key after the last menu item the T2000 returns
to the operational display currently in use.
The MODE MENU is designed to allow the operator fast easy access to functions and
parameters which may need to be adjusted in flight. Use MODE KEY to step though options.
Use the TOGGLE KEY to return to the operational display at any time.
QNH or Baro
The altitude encoder outputs a pressure altitude fixed at an above
mean sea level (AMSL) pressure of 1013mb or 29.92 HG. QNH/Baro
can be entered to allow the T2000 to compensate the displayed altitude
for surface pressure and hence read the same as the aircrafts
altimeter. If the QNH/Baro, is set to a discrete value (normally provided
by ATC) the encoder pressure altitude displayed will be adjusted for
that QNH/Baro value. The barometric units are set in the BARO option
of the PROGRAM MODE. When MB is selected the QNH screen is
displayed, and when HG is selected the BARO screen is displayed.
Press MODE key (once) to select QNH/Baro option
Rotate CODE SELECT knob and scroll lower line to desired
pressure. Press knob to move one place to left
Press ENTER key to set default value (1013mb or 29.92HG)
Assigned
(Altitude)
The user can input an assigned altitude given by ATC. When used with
the altitude buffer value, an audio alert and display indicator advises
when the aircraft has climbed or descended from the assigned altitude.
When the Altitude option of the mode menu is set to Feet or Flight
Level, the Assigned altitude is adjusted in feet. When the Altitude
option of the mode menu is set to Metres, the Assigned altitude is
adjusted in Metres.
Press MODE key (2 times) to select Assigned option
Press CODE SELECT knob to increment in units of 500 feet/100m
Rotate CODE SELECT knob to increment in units of 100 feet/10m
Press the ENTER key to return ASSIGNED ALTITUDE to 0
Press the TOGGLE key to save and return to operational display.
