NOTE : The ATC/mode S will be able to provide the Traffic Collision
____ Avoidance System (TCAS) with the aircraft address.
 For SSR interrogations, the transponder transmits the selectable code number
 (Mode A) or the barometric altitude (Mode C) if required.
 For SSR/Mode S all call interrogations, the transponder transmits the same
 information.
 In addition, new functionalities are required for ATC/Mode S transponders:

 -elementary surveillance (mandatory in Europe after March 31, 2003),
 -enhanced surveillance (mandatory in Europe after March 31, 2005). The transponder meets the requirements for elementary surveillance and has the capability for enhanced surveillance (ref. para. 6.A.(3).). It can also transmit extended squitters. Enhanced surveillance parameters and extended squitters are transmitted if the wiring provisions for enhanced surveillance are installed. Moreover, the following functionalities are available:
 -
com A/B: capability to receive ground to air data uplink (com A) and to transmit air to ground data downlink (com B) in addition to bidirectional data exchange

 -
com C: capability to receive Extended Length Messages (ELM) It also incorporates the following improvements:

 -it has interface characteristics in compliance with ARINC 718A.
 -as a Mark IV transponder, this transponder needs additional wiring to perform enhanced surveillance and extented squitters functions. If this wiring is not installed, the transponder will operate as a Mark III transponder. In this case, nor enhanced surveillance parameters neither extented squitters are available.
 -its software is fully loadable.
R 1EFF : 106-149, 221-299, 301-399, 401-499, 1 34-52-00Page 3 1 1 Aug 01/05 1 1 1CES 1 The transponder is a level 3 transponder since it is capable of processing

 com A/B/C/ data link messages.
 **ON A/C ALL
 2. Component Location
__________________
 (Ref. Fig. 001)

 -------------------------------------------------------------------------------FIN | FUNCTIONAL DESIGNATION | PANEL|ZONE|ACCESS | ATA | | | | DOOR | REF.
 -------------------------------------------------------------------------------1SH1 XPDR-ATC/MODE S, 1 81VU 127 824 34-52-33 1SH2 XPDR-ATC/MODE S, 2 82VU 128 824 34-52-33 7SH1 ANTENNA-ATC BOTTOM, 1 127 34-52-11 7SH2 ANTENNA-ATC BOTTOM, 2 128 34-52-11 7SH3 ANTENNA-ATC TOP, 1 224 34-52-11 7SH4 ANTENNA-ATC TOP, 2 223 34-52-11 3SH CTL UNIT-ATC/TCAS 11VU 211 831 34-52-12
 3. System Description
__________________

R **ON A/C 001-049, 101-105, 151-199, 201-220,
 A. Principle (Ref. Fig. 002) An airborne transponder provides coded reply signals in response to interrogation signals from the ground secondary radar and from aircraft which will be eventually equipped with the TCAS. This ground interrogation is transmitted in the form of pair of pulses P1 and P3 for the mode A or C and in the form of pulses P1, P3 and P4 for the mode S. The decoding of the time between the interrogation pulses determines the operating mode of the transponder :
 -
mode A (identification)

 -
mode C (altitude range)

 -
mode S (flight data)
 The interrogation frequency is 1030 MHz.
 The reply frequency is 1090 MHz.
 The system is provided with four antennas :

 -
two antennas are located at the upper part of the fuselage

 -
two antennas are located at the lower part of the fuselage. According to the aircraft configuration, the transponder selects the antennas (lower or upper) which receive the best transmission signal from the ground ATC secondary radar.

 1EFF : ALL 1 34-52-00Page 4 1 1 May 01/05 1 1 1CES 1

 ATC - Component Location Figure 001
 1EFF : 1 1R 1CES  ALL  1 11 1 34-52-00 Page 5 May 01/05

 ATC - Principle Figure 002 
R 1EFF : 1 1 1CES  ALL  1 111 34-52-00 Page 6 May 01/05

R **ON A/C 051-099,

R  A. Principle 
R  (Ref. Fig. 002) 
R  An airborne transponder provides coded reply signals in response to 
R  interrogation signals from the ground secondary radar and from aircraft 
R  which is equipped with the TCAS. 
R  The ATC/Mode S system has the capability for Modes A, C and S. 
R  Mode A: identification 
R  Mode C: altitude range 
R  Mode S: In a Mode S environment, the transponder responds to 
R  ATCRBS-formatted interrogations with ATCRBS-formatted replies, but, in 
R  addition, it can be discretely addressed directly by Mode S 
R  interrogators. Discrete addressing means that only the specifically 
　
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