ELT Teething Problems
A reader sent in his story of how his aircraft, parked on a grass strip, recently became the object of an ELT search. Unknown to him his ELT had been activated and was transmitting. We can imagine how he felt when a search aircraft appeared overhead and zeroed in on his downed aircraft. His aircraft was fitted with an ELT operated by a cockpit remote control switch. This switch has three positions: OFF/ARM/ON. The aircraft had been parked with the switch in the arm position. Apparently someone had momentarily switched it to the on position, activating the ELT, and had returned the switch to arm. Once activated, it must first be placed in the off position to shut off the transmissions before returning it to the arm position.
These false alarms can be prevented by turning your ELT switch to the off position before you leave the aircraft. Leave the switch in the arm position only in flight. It's a good idea to put these items in your pre-start and shutdown checklists now.
What about ELT false alarms from aircraft without an ELT cockpit remote control switch? In these installations the ELT control switch is on the ELT itself located to the rear of the aircraft. These aircraft are always flown and parked with the switch in the arm position. Unknown to you the ELT may have been activated by a hard landing, moving the aircraft on the ground, or by maintenance people working on the aircraft.
To ensure the ELT is not transmitting listen out on 121.5 before shutting down.
If you hear an emergency squawk check the switch on the ELT in the rear of your aircraft. This may necessitate opening an inspection panel. Turn the switch to the off position, return to the cockpit and again listen out on 121.5. If the ELT tone is gone then your ELT was the culprit. Now go back and reset your ELT switch back to the arm position and you should be ready for your next flight. Your ELT is now armed but not transmitting. Go back to the cockpit and make a final check on 121.5.
ELT Urgent Problem
As we go to print, another two ELT false alarms! One involved a Cessna 172 parked at Maple Airport and another Cessna 172 on floats docked on a lake in the Kenora area.
Each aircraft was located by search and rescue aircraft in less than three hours and the pilots advised their ELTs were transmitting. It's vital that you make that ELT listening-out check on 121.5 every time you shut down.
Originally Published: ASL 1/1998
Original Article: ELT Teething Problems; ELT Urgent Problem