Emergency Beacons


 There are three types of beacons used to transmit distress signals, EPIRBs (for maritime use), ELTs (for aviation use), and PLBs (hand held personal portable units used for multi-environment use).






Emergency Position Indicating Radio Beacon (EPIRB) 


imageEPIRBS are for use in maritime applications. The 406 MHz EPIRBs are divided into two categories. Category I EPIRBs are activated either manually or automatically. The automatic activation is triggered when the EPIRB is released from its bracket. Category I EPIRBs are housed in a special bracket equipped with a hydrostatic release. This mechanism releases the EPIRB at a water depth of 3-10 feet. The buoyant EPIRB then floats to the surface and begins transmitting. If you own a Category I EPIRB, it's very important that you mount it outside your vessel's cabin where it will be able to "float free" of the sinking vessel.  

Category II EPIRBs are manual activation only units. If you own one of these, it should be stored in the most accessible location on board where it can be quickly accessed in an emergency.  

406 MHz beacons are digitally coded and transmit distress signals without delay. This means that even a brief inadvertent signal can generate a false alert. To avoid getting a call from the Coast Guard make sure that when you test your EPIRB you follow the manufacturer's recommendations carefully. Or, follow these guidelines for general beacon testing & inspecting procedures. 

Also, make certain that you register your EPIRB. If for some reason your beacon does activate inadvertently and it is registered, the call you receive from the Coast Guard will be a friendly one. If it is not registered, it may not be quite so friendly. More importantly, registration will help rescue forces find you faster in an emergency and allow you to make an important contribution to the safety of others by not needlessly occupying SAR resources that may be needed in an actual emergency. If you need to register a 406 MHz EPIRB, you can now register online or you may download a beacon registration form from the registration website and then fax the form to us at:  (301) 817-4565.  For any other registration questions, please call us at:  1-888-212-SAVE (7283).

All Class A, B, and S EPIRBs operate on 121.5 or 243.0 MHz and have been phased out.  Class A, B, and S EPIRBs shall not be manufactured, imported, or sold in the United States on or after February 1, 2003.  Operation of Class A, B and S EPIRBs shall be prohibited after December 31, 2006.  (Code of Federal Regulations, Title 47, Part 80, Subpart V)

The U.S. Coast Guard has an outstanding website with even more information on EPIRBs. Click here to view the Coast Guard EPIRB Homepage.



Emergency Locator Transmitters (ELTs)


406 MHz beacons designed for use in an aircraft are known as an Emergency Locator Transmitter (ELT). ELTs can be manually activated by the pilot or automatically activated by a G-switch. ELTs transmit for at least 24 hours and most have the 121.5 MHz homing capability.

Some 406 MHz ELTs may also transmit a position within the distress alert. This position may be a one-time input from the aircrafts navigation system or may be periodically updated from a GPS processor internal to the ELT. The one-time position input may not represent the most accurate position of the ELT since it may not be known when that position was last inserted into the message.

Antiquated 121.5 MHZ ELTs are also available. The 121.5 MHz ELTs were intended to alert other aircraft flying overhead of a crash. Satellites are not listening for the 121.5 MHz ELT signal. A major limitation of a 121.5 MHz ELT is that another aircraft must be within range and listening to 121.5 MHz to receive the signal.

There are approximately 170,000 of the older generation 121.5 MHz ELTs in service. Unfortunately, these have proven to be highly ineffective. They have a 97% false alarm rate, activate properly in only 12% of crashes, and provide no identification data.
406 MHz ELTs dramatically reduce the false alert impact on SAR resources, have a higher accident survivability success rate, and decrease the time required to reach accident victims by an average of 6 hours.

Presently, most aircraft operators are mandated to carry an ELT and have the option to choose between either a 406 MHz ELT or a 121.5 MHz ELT. The Federal Aviation Administration has studied the issue of mandating carriage of 406 MHz ELTs. The study indicates that 134 extra lives and millions of dollars in SAR resources could be saved per year. No one can argue the importance of 406 MHz ELTs and the significant advantages they hold.

Due to the obvious advantages of 406 MHz beacons and the significant disadvantages to the older 121.5 MHz beacons, the International Cospas-Sarsat Program stopped monitoring of 121.5 MHz by satellites on February 1st, 2009.  All pilots are highly encouraged both by NOAA and by the FAA to consider making the switch to 406!

If you need to register a 406 MHz ELT, you can now register online or you may download a beacon registration form from the registration website and then fax the form to us at: (301) 817-4565.  For any other registration questions, please call us at:  1-888-212-SAVE (7283).


Personal Locator Beacons (PLBs) 


Hiker in snowPLBs are portable units that operate much the same as EPIRBs or ELTs. These beacons are designed to be carried by an individual person instead of on a boat or aircraft. Unlike ELTs and some EPIRBs, they can only be activated manually and operate exclusively on 406 MHz. Like EPIRBs and ELTs, all PLBs also have a built-in, low-power homing beacon that transmits on 121.5 MHz. This allows rescue forces to home in on the distress beacon once the 406 MHz satellite system has provided the necessary position information. Some PLBs also allow GPS units to be integrated into the distress signal.  This GPS-encoded position dramatically improves the location accuracy down to the 100-meter level…that’s roughly the size of a football field!

In 2016, PLBs were used in 78 separate events resulting in helping to save 122 lives.

If you need to register a 406 MHz PLB, you can now register online or you may download a beacon registration form from the registration website and then fax the form to us at: (301) 817-4565.  For any other registration questions, please call us at: 1-888-212-SAVE (7283).






Register Your Beacon

Without registration, the RCCs are unable to react as quickly…and ultimately this may delay a SAR response should you be in an emergency.  If you have a 406 MHz beacon and have not registered it, please do so by clicking here to access the National 406 MHz Registration Database. It’s the law and it may save your life!