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

Canadian Aviation Regulations (CARs) 2017-2

Content last revised: 1996/10/10

(a) Corrosion Inspection

ELTs installed in aircraft are subject to extreme environmental conditions which may cause corrosion to develop in circuit boards and battery compartments. As a minimum, corrosion inspection shall be performed during each required battery replacement and performance test.

(b) Operational Testing

Information Notes:

(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) The periodicity of operational checks is at the operator's discretion, but the check shall only be conducted during the first five minutes of any UTC , (co-ordinated universal time) hour, and restricted in duration to not more than five seconds.

An acceptable procedure for operational tests is to:

(1) Tune the aircraft or other VHF receiver in the area to 121.5 MHz;

(2) Activate the ELT for not more than five seconds, while monitoring the VHF receiver; approximately three ELT audio sweeps are to be heard;

(3) 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.

(c) Performance Testing

(1) Testing of any ELT shall be conducted in a screen room or metal enclosure, or, the transmitter power output shall be connected to a suitable dummy load to minimize radiation.

(2) For ELTs powered by other than water activated batteries, the performance test shall be performed using the ELT's own battery. An alternate power source can be used where lengthy servicing, other than the performance test, is anticipated.

(3) As a minimum, the performance test for ELTs powered by non water-activated batteries shall include:

(a) the measured peak power after 3 minutes of operation;

(b) the measured frequency after 3 minutes of operation;

(c) the audio modulation, which shall be recognisable as a typical ELT signal, and shall meet the specifications of the ELT manufacturer;

(d) the measured current draw in the "Arm" or "Auto" position, and in the "On" position as specified by the ELT manufacturer; and

(e) a test of the automatic activation system.

(4) Except for the automatic activation system test, the performance test for ELTs utilising water activated batteries shall include all of the above (see paragraph 3).

(5) 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.

(d) Battery Replacement and Recharging

(1) Battery manufacturers are required to indicate the type, model, part number, ELT type & model(s) for which the battery has been approved, and the battery's expiry date.

(2) The following general guidelines relate to the replacement of ELT batteries:

(a) only batteries approved for the particular ELT type are to be installed;

(b) following each battery replacement, recharge or capacity test, the date when the next replacement, recharge or capacity test 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;

(c) an operational test shall be performed following reinstallation in an aircraft of an ELT which has been removed for any reason.

(3) Non-rechargeable batteries shall be replaced by serviceable batteries:

(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; and,

(d) On or before the proposed battery replacement date.

(4) 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 established by the ELT manufacturer; and

(e) when the cumulative time of all known transmissions exceeds one hour.

(5) Capacity tests and recharging shall be accomplished at the time intervals, and in accordance with the procedures established by the manufacturer.

(6) Water-activated batteries shall be replaced by serviceable batteries after activation or under any other conditions specified by the ELT manufacturer.

(e) Shipping

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.

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