Document ID: chunk:federal_register_of_legislation:F2021C01280:reg:5:p18
Version: federal_register_of_legislation:F2021C01280
Segment Type: reg
Provision Reference: reg 5 (pt 18/26)
Character Range: 50996–53782

is installed in the aircraft; and
(b) after it is installed in the aircraft — at intervals not exceeding every 24 months.

14 Periodic checking and testing of ATC transponders

Definition
       14.1 In this clause:
electron tube technology or ETT means technology that uses the physical and electrical characteristics of a physical body to oscillate and amplify a signal at its resonant frequency for subsequent broadcast, including through thermionic valves, klystrons or cavity oscillators.
Note 1   As the components age, the characteristics which provide the signal stability vary which affects the output signal.
Note 2   Transponders using ETT include, for example, Honeywell (Bendix-King) KT76A, Narco AT150 and ARC RT859.

Application
       14.2 This clause applies to all air traffic control (ATC) transponders.

Testing
       14.3 Before an ATC transponder is used for the first time in an aircraft, it must be system tested in accordance with the requirements of Appendix F of FAR 43, using Mode A code 2100.
       14.4 After the test mentioned in subclause 14.3, and within the intervals mentioned in subclause 14.7, each ATC transponder must be system tested in accordance with the requirements of Appendix F of FAR 43, using Mode A code 2100.
Note   Consideration should be given to aligning this test with that required under clauses 3, 4 and 5 of this Appendix 1.
       14.5 After the test mentioned in subclause 14.3, without affecting the requirements under subclause 14.4, and within the intervals mentioned in subclause 14.8, each ATC transponder using ETT must also be tested in accordance with the requirements of Appendix F of FAR 43, using Mode A code 2100, to confirm that:
(a) the duration of all reply pulses (the pulse width) is at least 0.35, and not more than 0.55, microseconds; and
(b) the amplitude variation between 1 reply pulse and any other reply pulse is not more than 1 dB.
       14.6 An ATC transponder which fails to comply with any requirement under subclause 14.3, 14.4 or 14.5, must not be used in an aircraft until it has been:
(a) repaired or replaced in accordance with the requirements of CAR and CASR; and
(b) system tested in accordance with subclause 14.3 or 14.4, and tested in accordance with subclause 14.5 (if applicable).

Intervals
       14.7 For subclause 14.4, the interval is whichever of the following applies:
(a) within 24 months after the ATC transponder was first system tested in accordance with subclause 14.3, and at intervals not exceeding every 24 months after that;
(b) within 24 months after the date on which the same system test was last conducted under AD/Rad/47: Periodic Testing of ATC Transponders (as in force immediately before 22 December 2015), and at intervals not exceeding every 24 months after