ATC TCAS Panel
Description
The aircraft has two ATC transponders (XPDR) which are controlled by a control panel (ATC/TCAS) on the center pedestal.
Only the selected XPDR operates.
The XPDR automatically responds to requests:
- From the ATC, to ensure effective air traffic surveillance
- From other aircraft that have a TCAS, to ensure that traffic alerts are triggered.
The XPDR is capable of elementary surveillance (ELS) and enhanced surveillance (EHS). It transmits the following data to the ATC center:
‐ The aircraft 24 bit address, the aircraft altitude, the flight number, the RA report ‐ The indicated airspeed, the Mach number, and the barometric vertical speed that are all supplied by the ADRs ‐ The magnetic heading, the roll angle, the ground speed, the track angle, the track angle rate, and the inertial vertical speed, that are all supplied by the IRs ‐ The selected altitude and barometric reference settings supplied by the FCUs.
Usage
XPDR Selector
This switch selects XPDR 1 or 2.
Mode Selector
- STBY:
- Both XPDR are electrically supplied but do not operate.
- ON:
- Selected XPDR operates.
- AUTO:
- In flight : Selected XPDR operates.
- On ground : Selected XPDR only operates in mode S (Selective aircraft interrogation mode).
ALT RPTG Switch
- ON:
- The XPDR sends barometric standard altitude data.
- OFF:
- No altitude data transmission. If the TCAS is installed, the upper ECAM displays "TCAS STBY" in green.
IDNT Switch
- The flight crew presses this button to send the aircraft identification signal.
Code Display
- The window displays the selected code.
Keypad
- The flight crew uses the keypad to set the code assigned by ATC.
CLR Key
- The flight crew uses this key to clear the code display.
- Note: As long as the four figures of the new code are not entirely written, the previous code remains.
ATC FAIL Light
- This light comes on if the selected XPDR fails.