Emergency locator transmitter

It automatically sends a distress signal if its accelerometer senses a high G force, such as that encountered during an aircraft accident.

A 406-MHz ELT—which is the only type that can be installed on new general aviation aircraft—transmits a distress signal on the 406 MHz frequency, along with precise GPS coordinates, so that it can easily be located by authorities via a worldwide network of satellites.

Older-style 121.5-MHz ELTs can still be used on aircraft, but authorities no longer search for 121.5 MHz alerts by satellite. These ELTs can only be located by search and rescue pilots if they happen to fly close enough to hear the distress signal by radio.

Each 406-MHz ELT is programmed with a unique 15-character identification (ID) code, which is also transmitted as part of the distress signal when the ELT is activated. Operators must register their ELT ID code, aircraft information, and contact information with National Oceanic and Atmospheric Administration (NOAA) Search and Rescue Satellite-Aided Tracking.

When an ELT is activated, the Air Force Rescue Coordination Center (ARFCC) is the authority responsible for coordinating a search and rescue, most of which are carried out by the Civil Air Patrol and the Coast Guard.

Unfortunately, most ELT activations are false alerts, so the ARFCC will first try to contact the aircraft operator using the contact information provided to NOAA. There were more than 9,000 false alerts in 2023.

If you accidentally activate an ELT (for example, you notice the red light blinking on the ELT panel-mounted indicator), you should call ARFCC at 800-851-3051, or any air traffic control facility, right away to make them aware that a false alert was transmitted and should be canceled.

Kollin Stagnito is a commercial pilot and ground instructor.