September 2014- Five-and-a-half years ago, Search and Rescue Satellite (SARSAT) monitoring of the 121.5 MHz and 243 MHz emergency frequencies ceased. Citing statistics that indicated many more false alarms than actual emergencies, the international consortium that administers the global network of search and rescue programs called for mandatory conversion to a new system operating on 406 MHz beginning Feb. 1, 2009.
The consortium found that the inability to identify a specific emergency transmitter (121.5 MHz beacons transmit anonymously, and satellites cannot discern the difference between a beacon a non-beacon source) didn’t allow enough data for responders to determine exactly who was sending the signal.
According to a NOAA-SARSAT publication, the older 121.5 MHz technology was not just inaccurate, but expensive: “The only way to ascertain the situation is to dispatch resources to investigate—a costly disadvantage.”
To fix these shortcomings, the administrators of the consortium decided to design a new SARSAT technology that integrated GPS accuracy and used a registration system for individual transmitters. Such a system would allow comparison of a coded emergency signal with a database entry, so an alert would be traceable to a specific airplane, ship or other vehicle.
Using the new approach, a satellite could pinpoint the signal’s whereabouts with accuracy within 50 to 100 meters and determine exactly who was sending the signal.
Another benefit of the new system, according to the SARSAT group, was that emissions in the UHF spectrum penetrate low density material such as tree canopies better than 121.5 or 243 MHz signals, plus UHF signals “bounce” (i.e., are reflected) a bit more efficiently. Since many aviation emergencies occur in forested and/or mountainous areas, these physical characteristics were considered a plus.
Obviously better, but…
To a mission-oriented bureaucrat—a person that doesn’t have to pay the bill, in other words— the benefits completely abandoning the previous technology in favor of the proposed new system seemed obvious, compelling and unassailable. AOPA, however, had some reservations.
AOPA didn’t dispute that the proposed technology would be superior to the existing technology. AOPA simply pointed out that the financial burden on most General Aviation stakeholders was too great, as the new transmitters would cost thousands of dollars to purchase and install.
According to AOPA statistics, the majority of the group’s members flew simple, single engine airplanes in VFR weather for pleasure and recreation either locally or on short trips. These owners simply could not justify or afford the costly new transmitters.
After months of negotiation, AOPA hammered out a compromise with the authorities: if a typical General Aviation aircraft was not being used in a commercial venture, the owner could opt out of the mandate and continue to use older technology. That owner was voluntarily accepting a greater risk of not being located in the event of an emergency in return for lower aircraft ownership cost.
The installation and upkeep costs of 406 MHz ELTs have come down a little bit since 2009, but the majority of the noncommercial General Aviation fleet is still using the old technology. With Avgas at $7-plus per gallon and all the other built-in costs of private flying, most owners today continue to opt out of the program.
Entrepreneurs to the rescue
Given how fast technology moves, it was inevitable that SARSAT technology and its stated goals would give rise to something totally unforeseen after the rules were written. Technically minded individuals with an entrepreneurial bent are not constrained by the intentions of bureaucrats; they look at the rules and dream up new ways to use the technology. In this case, the unforeseen development was the evolution of the Personal Locator Beacon (PLB).
After the move to 406 MHz, technology quickly advanced toward miniaturization, a common occurrence with electronics. As vehicle-mounted devices became smaller, it wasn’t long before visionaries took a look at the SARSAT rules and decided there was no reason why individuals could not be equipped with tracking devices just like vehicles.
The methodology, the developers reasoned, could be the same as for vehicles: register the user with a unique code, and then put the code plus the person’s name, phone number and address into the database exactly as was being done with unique vehicle identifiers.
With a lightweight, long-life battery on a miniaturized 406 MHz ELT, a new device, now named a personal locator beacon (PLB), was mass marketed to the general public at an affordable price. The elderly, hikers, children, cab drivers, over-the-road truckers, boaters—and of course, airplane pilots—suddenly would have an inexpensive way to summon help with the press of a button.
The most capable PLB
Today, there are several products on the market. In my opinion, the most capable PLB is manufactured by ACR Products under the model name of ResQLink+. This device has full-time emergency tracking and one purpose: to send an emergency alert to the orbiting emergency tracking satellites managed by the United States (SARSAT) and those monitored by Russia (COSPAS) when the activation button is pressed.
It has a battery shelf life of five years, GPS location integration, a high-powered 5 watt transmitter and exceeds the required 24 hours of continuous SOS operation once activated. Like all emergency tracking devices that do not have an accelerometer to trip the device in the event of a crash, if the pilot and passengers do not survive, the device does nothing.
If there are survivors, though, the SARSAT/COSPAS centers will have the location—anywhere in the world—nailed to within a few hundred feet, and do so after just a few minutes of the device’s activation. The authorities will also know who is listed as the owner of the PLB, their contact information, phone number and home address. The device does not allow text messaging.
Street price for the ResQLink+? A one-time outlay of about $275 with no annual fee.
Variety abounds for global PLBs
There are also several PLB devices available that allow text messages to be sent along with an emergency-specific signal. These devices don’t use the SARSAT/COSPAS satellite constellations, but instead use commercial satellite constellations—and charge a monthly fee for tracking and texting services. This fee is over and above the cost of the device itself.
Depending on the product, the user can be limited to a specific number of texts each month, usually “canned” text messages (e.g., “I’m OK,” or “I need help,” etc.).
Some services also allow free-form texts—and one in particular allows two-way texting anywhere on the planet. (This isn’t without a fee, of course.)
A few are texting devices with an emergency activation button, but they have no centrally located emergency status monitoring center. These devices are useful for messaging but virtually useless for full-time emergency event tracking since they depend on an individual—such as a friend or relative of the owner of the device—being available 24/7, 365 to receive the emergency message and take action.
Before you purchase one of these notification devices, do some homework to determine if the company offers a fully staffed emergency management center that will contact a SARSAT/COSPAS center if they receive an emergency signal.
Here’s a list of some of the more popular texting devices and their features, with all but one offering some type of SOS capability:
• DeLorme’s inReach satellite messenger: Street price is around $250, plus annual fee. SOS feature plus optional two-way free-form texting. Uses commercial satellite constellation, not SARSAT/COSPAS. GPS location integration, 1.6 watt transmitter, 120 hours of continuous operation. Minimum annual subscription fee is a bit over $100; full two-way texting costs considerably more.
• SPOT Connect satellite messenger: Street price around $99, plus annual fee. SOS text feature only—no other texting. Uses commercial satellite constellation, not SARSAT/COSPAS. GPS location integration, transmitter power unknown, 108 hours of continuous operation. Minimum annual subscription fee is a bit under $100.
• Apple iPhone’s “Find my Friends” app: Free to install. Only works when cell phone is on and functioning. Sends location information from cell phone to a designated receiver. Limited use as an emergency notification device. Text is via the cell phone host. No annual fee.
Bottom Line
If you are looking for portable, satellite based texting devices, there are several possibilities for your consideration. Some allow two-way texting and the coverage is global, but emergency signaling for this class of PLBs is not via the SARSAT/COSPAS system and they may or may not have a central monitoring station that is staffed around-the-clock.
Rumors abound that dual systems—those with commercially-based texting capabilities and SARSAT/COSPAS-based emergency signaling— are in the works. But for now, if you’re looking to move into the 406 MHz world inexpensively, the ResQLink+ from ACR Products is, in my opinion, the closest you can come to a traditional airplane-mounted 406 MHz ELT.
Remember, as far as SARSAT/COSPAS is concerned, the device is tracking you, not your airplane. As long as you take it with you, you can use it to request help anytime you venture into an area where assistance is not readily available. Or, if you are flying a rental airplane, or an airplane belonging to a friend, you can augment whatever ELT system is installed in that aircraft with your own portable PLB.
For about $250 to $275 this level of detectability seems like a bargain. And if it doesn’t seem like a bargain to you now, it will be if you ever need the help this system provides.
John Loughmiller is a 4,700-hour commercial pilot and CFII MEI-A. He lives in Kentucky with Donna, his wife of 40 years, and often commits random acts of aviation. Send questions or comments to editor@piperflyer.org.
RESOURCES
Further reading
“Comparison of the 406 MHz and 121.5 MHz Distress Beacons”
One-page reference document published by NOAA-SARSAT
www.sarsat.noaa.gov/406vs121.pdf
Popular devices
ACR Electronics, Inc.
ResQLink+
acrartex.com/products/catalog/personal-locator-beacons/resqlink-plb
Apple Inc.
Find My Friends
apple.com/apps/find-my-friends
DeLorme
inReach Explorer
inreachdelorme.com
Spot LLC
Spot Connect
findmespot.com/en
