Part V - Standard 571 Appendix G - Maintenance of Emergency Locator Transmitters (ELTs)

Canadian Aviation Regulations (CARs)
(effective 2019/08/01)

Introduction

The following are the standards of airworthiness for ELTs:

  • (1) Operational Test: ELTs capable of transmitting on the 121.5 MHz frequency

    Information note:

    • (i) ELT operational tests only provide the aircraft operator with an indication that the ELT is transmitting; however, a positive result cannot be interpreted as meaning that the ELT meets all operational parameters.
    • (ii) Pursuant to subsection 605.40(2) of the Canadian Aviation Regulations, the operational tests shall only be conducted during the first five minutes of any UTC (coordinated universal time) hour, and restricted in duration to not more than five seconds.
    • (a) Operational tests shall be conducted as follows:
      • (i) tune the aircraft or other VHF receiver in the area to 121.5 MHz frequency;
      • (ii) activate the ELT for not more than five seconds, while monitoring the VHF receiver. Approximately three ELT audio sweeps are to be heard;
      • (iii) reset the ELT to ARM or AUTO, as applicable, and continue to listen to 121.5 MHz for a few seconds to ensure that the ELT does not continue to transmit after the test is terminated.
  • (2) Performance Testing: ELTs capable of transmitting on the 121.5 MHz frequency

    Information note:

    • (i) Performance testing is conducted in the active transmission mode of the ELT and should be carried out in a suitable RF shielded environment. Shielded boxes with a provision to also incorporate the test equipment, or feeders to it, are available for this purpose.
    • (ii) Attaching a non-radiating load to the ELT output will not necessarily prevent signal reception as the signal may be transmitted directly through the interface to the dummy load or from the ELT enclosure itself.
    • (a) for ELTs powered by non-water-activated batteries, the performance test shall be performed using the ELT's own battery.
    • (b) as a minimum, the performance test for ELTs powered by non-water-activated batteries shall include:
      • (i) an inspection of the ELT (elements could include inspecting the case, connector, physical damage, fluid contamination, corrosion, etc.);
      • (ii) the measured peak power after 3 minutes of operation;
      • (iii) the measured frequency after 3 minutes of operation;
      • (iv) the audio modulation, which shall be recognizable as a typical ELT signal, and shall meet the specifications of the ELT manufacturer;
      • (v) the measured current draw in the "Arm" or "Auto" position, and in the "On" position as specified by the ELT manufacturer; and
      • (vi) a test of the automatic activation system.
    • (c) For ELTs powered by water-activated batteries, the applicable performance test elements are outlined in section (b) above, items (i) to (v) inclusively.
    • (d) Following satisfactory completion of a performance test, the date on which the test was performed shall be marked on the external casing in a legible and permanent manner.
  • (3) Operational Test: ELTs capable of transmitting on the 406 and 121.5 MHz frequencies:

    Information note:

    • (i) Live testing of the 406 MHz transmission is not permitted at any time, but there is no restriction on performing the self-test transmission. However, the 121.5 MHz test transmission is not formatted or modulated to be identified as a test transmission, therefore if the self-test transmission activates the 121.5 MHz transmission, pursuant to subsection 605.40(2) of the Canadian Aviation Regulations, the test shall only be conducted during the first five minutes of any UTC (coordinated universal time) hour, and restricted in duration to not more than five seconds.
    • (ii) ELTs that do transmit on 406 MHz during self-test must comply with COSPAS-SARSAT requirements in that the 406 MHz transmission will be a single burst that has a specific digital frame synchronization that is recognized by the COSPAS-SARSAT system as being a test message and will therefore not be processed as a real alert. Before conducting any test, it is advised that the functionality of a particular ELT during self-test is confirmed from the manufacturer’s data.
    • (iii) Care must be taken to initiate the ELT self-test only as prescribed by the ELT manufacturer, as there may not be a control switch position explicitly identified as ‘TEST.’ The test sequence may, in some cases, be initiated by a specific timing and sequence of the ‘ON’ and ‘OFF’ controls.
    • (a) Operational tests shall be conducted as follows:
      • (i) initiate the ELT self-test only as prescribed by the ELT manufacturer;
      • (ii) verify that the light or series of lights on the ELT and, where applicable, the control panel, which may be accompanied by an aural alert, indicate proper functionality of the transmitters;
      • (iii) verify proper aircraft 24-bit address; and
      • (iv) if the self-test function activates the 121.5 MHz transmission, during the operational test:
        • (A) tune the aircraft or other VHF receiver in the area to 121.5 MHz;
        • (B) monitor the VHF receiver; ensure that ELT audio sweeps are to be heard; and
        • (C) reset the ELT to ARM or AUTO, as applicable as per the manufacturer’s instructions, and continue to listen to the 121.5 MHz signal for a few seconds to ensure that the ELT does not continue to transmit after the test terminates.
  • (4) Performance Test: ELTs capable of transmitting on the 406 and 121.5 MHz frequencies:

    Information note:

    • (i) Performance testing is conducted in the active transmission mode of the ELT (i.e. not self-test mode) and should only be carried out in a suitable RF shielded environment. Shielded boxes with a provision to also incorporate the test equipment, or feeders to it, are available for this purpose.
    • (ii) Attaching a non-radiating load to the ELT output will not necessarily prevent signal reception at the satellite as the signal may be transmitted directly through the interface to the dummy load or from the ELT enclosure itself.
    • (a) For ELTs powered by non-water-activated batteries, the performance test shall be performed using the ELT’s own battery, in accordance with the manufacturer’s instructions.
    • (b) As a minimum, the performance test for ELTs powered by non-water-activated batteries shall include:
      • (i) an inspection of the ELT (elements could include inspecting the case, connector, physical damage, fluid contamination, corrosion, etc.);
      • (ii) the measured peak power of the 406 MHz and 121.5 MHz transmissions, in accordance with the manufacturer’s instructions;
      • (iii) the measured frequencies of the 406 MHz and 121.5 MHz transmissions, in accordance with the manufacturer’s instructions;
      • (iv) verification of 406 MHz digital message (i.e. identification and position);
      • (v) the 121.5 MHz audio modulation, which shall be recognizable as a typical ELT signal, and meet the specifications of the ELT manufacturer;
      • (vi) the measured current draw, as specified by the ELT manufacturer; and
      • (vii) a test of the automatic activation system, in accordance with the manufacturer’s instructions;
    • (c) For ELTs powered by water-activated batteries, the applicable performance test elements are outlined in paragraph (b) above, subparagraphs (i) to (vi) inclusively.
    • (d) Following the satisfactory completion of a performance test, the date on which the test was performed shall be marked on the external casing in a legible and permanent manner.
  • (5) Battery Maintenance: ELTs capable of broadcasting on 121.5 MHz and ELTs capable of broadcasting on the 406 and 121.5 MHz frequencies
    • (a) Batteries shall be maintained in accordance with the manufacturer’s instructions.
    • (b) Battery Replacement
      • (i) Non-rechargeable batteries shall be replaced
        • (A) after use of the ELT in an emergency;
        • (B) after an inadvertent activation of unknown duration;
        • (C) when the cumulative time of all known transmissions exceeds one hour; or
        • (D) on or before the battery replacement date.
      • (ii) Batteries specified in the approved type design of the ELT or which have been approved for use for the particular ELT type shall be used.
      • (iii) An inspection of the battery shall be conducted (elements could include inspecting the case, connector, physical damage, fluid contamination, corrosion, etc.)
      • (iv) ELT batteries shall be installed in accordance with the ELT manufacturer’s instructions.
      • (v) Following each battery replacement, the date when the next replacement prescribed maintenance becomes due shall be marked in a legible and permanent manner on the external casing of the ELT and, where the ELT is installed on a life raft, on the outside of the life raft.
      • (vi) An operational test of the ELT shall be performed following a battery replacement.
    • (c) Battery Recharging
      • (i) Rechargeable batteries shall be recharged:
        • (A) immediately before the ELT is installed in an aircraft;
        • (B) after use in an emergency;
        • (C) after an inadvertent activation of unknown duration;
        • (D) at the time intervals specified by the ELT manufacturer; or
        • (E) when the cumulative time of all known transmissions exceeds one hour.
    • (d) The date when the next prescribed maintenance becomes due shall be marked in a legible and permanent manner on the external casing of the ELT and, where the ELT is installed on a life raft, on the outside of the life raft.
    • (e) An operational test of the ELT shall be performed following a battery replacement or recharging.
  • (6) Shipping: All ELTs

    When shipping an ELT, the battery shall be disconnected. If that is not practicable, the ON/OFF/ARM switch shall be secured in the "OFF" position, in accordance with the ELT manufacturer’s instructions.

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