Message Name:

EMERGENCY LOCATOR NOT TRANSMIT WHEN ELT SWITCH IS ON

The Emergency Locator Transmitter (ELT) does not transmit when the cockpit ELT switch is set to ON. EICAS message ELT TRANSMITTING does not show.

• Emergency Locator Transmitter (ELT) (A220)
• Emergency Locator Transmitter (ELT) Antenna (E54)
• Emergency Locator Transmitter (ELT) Cockpit Control Panel (AP1)
• Associated Wiring

Advisory Wire/Service Bulletin: None

Forum Articles/Infoservice/Newsletter: None

Notice To Operators (NTO): None

Flight Operation Notifications Manual (FONM): None

1. Perform the ELT self-test in the baggage compartment.
2. Set the ON/OFF switch on the ELT to ON. Make sure that the red LED on the ELT flashes continuously.

   1. If the red LED on the ELT does not flashes continuously, repair as required and do close out.
   2. If the red LED on the ELT flashes continuously, continue with next step.

3. Set the switch to OFF. Make sure that the LED light stays ON for 1 second approximately and goes OFF.

   1. If the LED light stays ON for 1 second approximately and goes OFF, go to step 4.
   2. If a problem is sensed, the LED will give coded signals after the 1 second period as follows:

      Coded Signals	Indication
      1 Flash	G-switch loop open problem
      3 Flashes	406.025 MHz transmitter problem
      5 Flashes	navigation data not present (ELT/NAV interface unit)
      7 Flashes	battery problem

4. Check if there is a coded signal or no LED indication (self-test at ELT is unsatisfactory).

   1. If there is no coded signal, go to step 7.
   2. If there is coded signal, continue with next step.

5. Examine the condition of the wiring at connector A220P1 for damage. Is there damage?

   1. If NO, go to step 14.
   2. If YES, repair the damage and do the ELT self-test again.

6. Check if the emergency locator system is serviceable.

   1. If the emergency locator system serviceable, do close out.
   2. If the emergency locator system is unserviceable, go to step 9.

7. Examine the condition of the wiring at connector AP55P1. Is there damage?

   1. If NO, replace ELT cockpit remote control switch and do close out.
   2. If YES, repair the damage and do the ELT self-test again.

8. Check if the emergency locator system is serviceable.

   1. If the emergency locator system serviceable, do close out.
   2. If the emergency locator system is unserviceable, continue with next step.

9. Remove the DAU 2 to get access to electrical connector A18AP1.
10. Check if there is no ELT TRANSMITTING advisory message and the ELT self-test is satisfactory.

    1. If ELT self-test is not satisfactory, go to step 12.
    2. If ELT self-test is satisfactory, continue with next step.

11. Perform a continuity check between the ELT, DAU 2 and the cockpit switch connectors as follows:

    From	To	Result
    A220P1-2	A18AP1-C9
    A220P1-3	AP55P1-14
    A220P1-6	AP 55P1-15
    A220P1-7	AP55P1-16
    A220P1-5	A220P1-8
    A220P1-11	GS981
    AP 55P1-21	GS980
    AP55P1-22	GS980

    1. If there is no continuity, repair defective wiring as required and do close out.
    2. If there is continuity, continue with next step.

12. Check if the coaxial cables are good.

    1. If coaxial cables are good, replace the ELT antenna and do close out.
       NOTE: Examine the condition of the coaxial cables before you replace the ELT antenna.
    2. If coaxial cables are not good, continue with next step.

13. Perform a wiring resistance/insulation check between the connectors of the coaxial cables that follow:

    From	To	Result
    A220P2	E54P1
    A220P3	E54P2

    1. If the resistance/insulation check is unsatisfactory, repair defective as required and do close out.
    2. If the resistance/insulation check is satisfactory, continue with next step.

14. Replace ELT.
15. Do close out.