Download the PDF consolidation of Part 43 [PDF 264 KB]
This appendix applies to a person referred to in rule 43.63.
(a) The ATC transponder tests may be conducted using a suitable bench check or portable test equipment.
(b) If portable test equipment with appropriate coupling to the aircraft antenna system is used, operate the test equipment for ATCRBS transponders at a nominal rate of 235 interrogations per second to avoid possible ATCRBS interference.
(c) For Mode S, operate the test equipment at a nominal rate of 50 Mode S interrogations per second.
(d) An additional 3 dB loss is allowed to compensate for antenna coupling errors during receiver sensitivity measurements conducted under paragraph E.4 (a)(3) below when using portable test equipment.
(a) For all classes of ATCRBS transponders, interrogate the transponder and verify that the reply frequency is 1090±3 MHz.
(b) For classes 1B, 2B, and 3B Mode S transponders, interrogate the transponder and verify that the reply frequency is 1090±3 MHz.
(c) For classes 1B, 2B, and 3B Mode S transponders that incorporate the optional 1090±1 MHz reply frequency, interrogate the transponder and verify that the reply frequency is correct.
(d) For classes 1A, 2A, 3A, and 4 Mode S transponders, interrogate the transponder and verify that the reply frequency is 1090±1 MHz.
(a) When classes 1B and 2B ATCRBS Transponders, or Classes 1B, 2B, and 3B Mode S transponders are interrogated at a rate between 230 and 1000 Mode 3/A interrogations per second or when Classes 1A and 2A ATCRBS Transponders, or Classes 1B, 2A, 3A, and 4 Mode S transponders are interrogated at a rate between 230 and 1200 Mode 3/A interrogations per second—
(1) verify that the transponder does not respond to more than 1 % of ATCRBS interrogations when the amplitude of P2 pulse is equal to the P1 pulse; and
(2) verify that the transponder replies to at least 90 % of ATCRBS interrogations when the amplitude of the P2 pulse is 9 dB less than the P1 pulse.
(b) If the test is conducted with a radiated test signal, the interrogation rate must be 235±5 interrogations per second unless a higher rate has been approved for the test equipment used at that location.
(a) Verify that, for any class of ATCRBS Transponder, the minimum triggering level of the receiver for the system is -73±4 dBm, or that for any class of Mode S transponder, the minimum triggering level of the receiver for Mode S format (P6 type) interrogations is 74±3 dBm by use of a test set—
(1) connected to the antenna end of the transmission line; or
(2) connected to the antenna terminal of the transponder with a correction for transmission line loss; or
(3) utilising radiated signals.
(b) Verify that the difference in Mode 3/A and Mode C receiver sensitivity does not exceed 1 dBm for either any class of ATCRBS transponder or any class of Mode S transponder.
Verify that the transponder RF output power is within the following specifications for the class of transponder using the conditions prescribed in paragraph E.4 (a):
(a) For class 1A and 2A ATCRBS transponders, the minimum RF peak output power is at least 21.0 dbw (125 watts):
(b) For class 1B and 2B ATCRBS transponders, the minimum RF peak output power is at least 18.5 dbw (70 watts):
(c) For class 1A, 2A, 3A, and 4 and those Class 1B, 2B, and 3B Mode S transponders that include the optional high RF peak output power, the minimum RF peak output power is at least 21.0 dbw (125 watts):
(d) For class 1B, 2B, and 3B Mode S transponders, the minimum RF peak output power is at least 18.5 dbw (70 watts):
(e) For any class of ATCRBS or any class of Mode S transponders, the maximum RF peak output power does not exceed 27.0 dbw (500 watts).
For any class of Mode S transponder that incorporates diversity operation, verify that the RF peak output power transmitted from the selected antenna exceeds the power transmitted from the non-selected antenna by at least 20 dB.
Interrogate the Mode S transponder using the correct address and at least 2 incorrect addresses and making the interrogations at a nominal rate of 50 interrogations per second and verify that it replies only to its assigned address.
(a) Interrogate the Mode S transponder with UF for which it is equipped and verify that the replies are made in the correct format using the surveillance formats UF=4 and 5.
(b) Verify that the altitude reported in the replies to UF=4 are the same as that reported in a valid ATCRBS Mode C reply.
(c) Verify that the identity reported in the replies to UF=5 are the same as that reported in a valid ATCRBS Mode 3/A reply, if the transponder is so equipped, using the communication formats UF=20, 21, and 24.
Interrogate the Mode S transponder with the Mode S-only all-call format UF=11, and the ATCRBS/Mode S all-call formats (1.6 microsecond P4 pulse) and verify that the correct address and capability are reported in the replies (downlink format DF=11).
Interrogate the Mode S transponder with the ATCRBS-only all-call interrogation (0.8 microsecond P4 pulse) and verify that no reply is generated.
Verify that the Mode S transponder generates a correct squitter approximately once per second.
(a) Verify that the ADS-B system meets the transponder performance requirements specified in a notice required by rule 91.258, demonstrated using an appropriate transponder test set.
(b) Test reports must be retained in the aircraft maintenance records.
