It’s Time To Sunset The ELT Requirement


In the midst of plowing through almost 300 accident reports for my research on ELTs, I took a break to actually look at a couple of installations in real airplanes. One word came to mind: ridiculous. Actually, maybe two words: Half-assed.

This is my general reaction to the requirement for ELTs in civil aircraft and it’s now time to rescind this regulation, in my view. Or, if the body politic doesn’t have the guts for that, make this addition to CFR 91.207: (10) (iii) Except this requirement doesn’t apply if at least one working personal locator beacon or satellite communicator is aboard the aircraft. In other words, allow for equivalency that unsaddles owners from unreasonable expense by leveraging improved technology, specifically ADS-B, cellphones, PLBs and satellite trackers.

The ELT requirement, which dates to 1973, was never a good idea. The best you can say is that if it wasn’t bad public policy, it certainly wasn’t good policy. These things just never worked that well in airplanes and certainly not well enough to justify the expense of a fleetwide mandate. Newer 406 MHz beacons are an improvement, but the two installations I looked at had the same weakness beacons have had for a half century. A vulnerable mount and a dinky coaxial cable connected to a whip antenna.

In a 2017 report, NASA found these to be continuing weak points and they’re a common feature in accident reports where there’s enough detail to determine if the beacon functioned or failed. And here a brickbat for the NTSB. Many accident reports just don’t reveal whether the ELT worked or not or aided in crash location. For an agency devoted to air safety, this is a significant failing. In an Embry-Riddle masters thesis in 2011, a researcher named Ajit Jesudoss was frustrated by the lack of detail in reports and subsequent researchers have encountered same. So did I in my research.

This suggests to me that between the FAA and NTSB, neither is taking this aspect of safety seriously enough to evaluate it, yet owners are still expected to buy, install, register and maintain these devices whose efficacy appears to be mediocre at best. (I found one exceptional NTSB investigation, so clearly some investigators have an interest in this aspect of safety.)

NASA suggested the mechanical and electric failures it found could be addressed with revised minimum operational performance standards for ELTs, but I say don’t bother. There are better ways to do this.

As I reported in the video, CAP relies more on cellphone tracking and ADS-B and radar data than it does on ELTs. CAP’s operations director John Desmarais told me they used to do more than 900 ELT missions a year, but last year did only 330. Thirty years ago, they flew 20,000 SAR hours a year, now it’s less than 2000. From a computer terminal, CAP’s radar team can pull up ADS-B tracking data in mere minutes. ELTs may be nice to have, but if they were ever critical, they aren’t now.

ELT logic has always been clouded by you-never-know thinking and the notion that even if it doesn’t work very well, an ELT might save your bacon. In other words, saving a single life makes it worth owners investing $300 million in ELTs that work in fewer than half of crashes.

There’s some truth to this, but my review of accidents just doesn’t turn up a lot of these situations, the classic nightmare being that you’re injured and trapped inside the wreckage. That risk exists, but, in my view, is not so large as to require expensive ELTs.

If the requirement were rescinded, my guess is most owners would still equip, although I wouldn’t put a 406 in the Cub. I would install one if I flew much in the mountain west and definitely in Alaska. My money would be spent on a PLB or satellite communicator. They’re cheaper, they work better and the FAA stays out of it.

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  1. I agree but wasn’t the requirement a congressional mandate, requiring congress to rescind any mandate for the ELT? With all of the stats the NTSB wants it strange that they don’t track that also. On the other hand NTSB has not commented on certain training providers no longer following the “train as you do, do as you train” attitude. To avoid the “M” word my point is that maybe the NTSB is not as immune to politics as some might think. Even if it was possible to eliminate the ELT requirement I doubt many foreign governments or even ICAO would go along. Not that I care what ICAO thinks!

    • Matt refers to foreign governments. For the record, in Europe for aircraft with 6 or less passengers not operated commercially a PLB is all you need on board (and as Paul suggests in his report is probably better than a fixed ELT anyway).

  2. This debate has been underway in Canada also. Here’s a general-public news article which lays out many of the points of view: “Why do some planes in Canada lack potentially life-saving emergency beacons?”, CBC Nova Scotia, November 8, 2018, . COPA, the Canadian pilots association, objects to an ELT mandate: “COPA Objects to TCCA’s New ELT Mandate Proposal”, July 4, 2019, . My own approach was to bring along a tracking beacon on cross-country flights. It seems much safer to rely on a device + power + antenna + orientation combination to work before the crash, and require it to stop working when the crash happens, than to ask it to do nothing while the aircraft is intact but to function flawlessly after the crash happens.

    • Be careful on any Canadian comparison. There are some search and rescue procedures and rules they have that we do not. For example if you file an IFR flight plan and don’t use it like we can do here in the US, the Canadian authorities start looking for you, and can get very upset with you when they find out the unused IFR flight plan was not cancelled.

  3. ADSB takes the search out of search and rescue. It is past time to move on from 1970’s ELT technology

    • Kind of. If it’s satellite ADS-B, then yes, but we don’t have that in the US. The process for ATC to use ADS-B to help S&R is not all that much different than how they do the same thing with radar targets. So as long as there is ADS-B coverage (line of sight), then yes, but there are still lots of situations where you won’t have ADS-B coverage or the last hit was a long ways from where your aircraft ended up.

  4. Paul is right. I love trackers and have had APRS, amateur radio GPS trackers in my cars and airplanes for 20 plus years. Great stuff. Now ADS-B and the likes of FlightAware make finding airplanes trivial. ELTs should be optional.

  5. Paul, why did you say “I would install one if I flew much in the mountain west”? Do the better alternatives not work well there?

    • Because in the vast majority of accidents, the site is located via other means much sooner than it’s necessary to use ADS-B or resolve a 406 position. In remote mountain areas–especially Alaska–that’s less true. So I’d make the argument that a belt-and-suspenders approach of having both the ELT and the PLB could be justified.

      In the video is a picture of a crash site in the mountains of Virginia. The 121.5 ELT functioned, but had a PLB been available, the survivor almost certainly would have been rescued without a night in the woods.

  6. One hundred percent agree, Paul. Who cares where the crashed airplane is anyway, I want them to find me, so a PLB makes so much more sense. Oh wait, the ELT was a congressional mandate…making sense I guess is not a determining factor.

  7. Probably because I grew up after ELTs were required, I never really thought much of them and just expected all GA aircraft to have one, much like someone who grew up during the smoking era just expected all cars to have ashtrays. But perhaps like the ashtrays, it is time to get rid of the ELT requirement. It’s a payphone in the days of cellphones.

  8. When my friend went down, the FAA showed up at the crash site, the first thing he asked was, “Did the ELT go off ?” I turned and walked into the burned wreckage that hours before had been a T-6 and pulled out a glob of molten plastic and circuit boards and handed it to him and said, I don’t know, why don’t you tell me. I did not score any brownie points that day. ELTs are worthless excess weight and expense that are not needed.

  9. Thanks for a great article, Paul! While I agree with “almost” every point, you did however make a couple of statements that I wouldn’t quite agree with. In your article you say “For an agency devoted to air safety, this is a significant failing” and “This suggests to me that between the FAA and NTSB, neither is taking this aspect of safety seriously enough to evaluate it”. In my 43 of active flying, I have learned that the FAA has almost no interest in “safety” (all they care about is control). Over the years, technology has produced equipment that is far superior to most anything we have used in our planes , yet FAA moves like a dinosaur when it comes to embracing this technology. While I realize that some of this technology has made it’s way into the cockpit, I don’t feel that the FAA has done much to make it easy.

  10. Did we touch on the several hundred dollar, soldered together, D-cell battery replacement cost every ~2 1/2 years? AmericaKing, who made an ELT you could actually use store-bought batteries was put out of business. The 406MHz ELT actually simulcasts on 121.5MHz as well. Otherwise, the ~once a minute 406MHz broadcast wouldn’t be often enough for close-in tracking by air…. (as learned by CAP Mission Pilots).

  11. Oops; should have watched the Cheap pilot commentary first which goes into this exact subject of replacement battery costs. We just did a C-172G1000 and C-182/G1000 costing ~$1k for both.

  12. A PLB that requires activation by a live person rarely substitutes for a G-activated ELT in an unanticipated crash. ADS-B and cell phones are helpful technology, but I’ll keep my ELT for just that reason.

    • Agreed. Nobody is addressing the primary advantage of an ELT – *Automatic* notification of a crash.

      PLBs, ADS-B, cell-phone, etc., all require some level of manual activation. None of them will automatically notify anyone that a crash has occurred. It’s somewhat like thinking “I’ll buckle my seat-belt *just* before I hit.” Or, it requires a loved one at home thinking, “hmm, it’s been hours, he should’ve been home by now…” before a search is launched. Way too long.

      It sounds like the real problem with current ELTs is all in the means of sensing a crash. Fix THAT problem and then it becomes useful. All the rest (PLB, ADS-B, cell-phone) are just a means to quickly locate the crash, but none will initiate the search on their own. Only an ELT is designed to automatically start the search and rescue process.

  13. If the ELT aided in the discovery and rescue in anyway it is reported by the agency that found and rescued the aircraft occupants. Just look through media reports to find ‘every time’ the ELT assisted. The NTSB/FAA doesn’t need to emphasize the relevance of the ELT because the CAP, Coast Guard and other S&R groups will ‘always’ let everyone know. The NTSB/FAA is too worried about your ‘Not’ Filed Flight Plan.

    Alaska has the most missing aircraft. Obviously, the missing aircraft have ELT’s installed. Before GPS, Alaska pilots purchased Handheld VHF radios. Can’t tell you how many times the downed pilot contacted an aircraft over head and relayed rescue instructions. You never hear or read about those accidents because we keep them out of the system. Today you’ll be hard pressed to find a pilot that flies remote areas without an Inreach or Spot. There’s a feature that instantly texts a message to listed cell phones when the aircraft speed is less then 35 knots. Then it text again when the speed goes over 35 knots. This texting feature could readily be implemented with the ADS-b technology. The text is totally automated (24/7) and provides the coordinates, time and link to a map. Rarely the aircraft will lose satellite contact but when satellite connection is reestablished you get another text.

  14. This is a market opportunity as well. Given that the GPS devices are already a market item, it’s a whole new sector of the economy to avail themselves of. It would take two screws and some adhesive to put a buttonless unit on the tail empennage and replacing the lithium battery every two years would only cost, well, it’s airplane stuff so add a zero to the retail price, but you know.

  15. After talking with CAP and Search and Rescue friends, I’m convinced that carrying a cell phone that is powered up is far more useful than the ELT, unless you are in an area that has no cell phone coverage. And as Paul states, then you have to take the chance that the ELT survives the crash. I have the old 121.5 ACK unit. Flying at the low end of the Aviation feeding chain with an Aeronca, I really try to keep safe within a budget. At any rate, the folks involved in search and rescue run to the cell phone records as soon as possible. We still have some folks who have crashed in Puget Sound that we haven’t located in decades. . . cell phone pings would have helped a lot, far more than the ELT.

  16. Interesting information. Hilarious ending. Good job! I have been reading every word you write for decades. I sure appreciate all the funny and informative work you have done. I nominate you for the “Gordon Baxter Aviation Writer’s Lifetime Achievement Award” (there should be such a thing). Thanks again.

  17. I would recommend reading up on 406mhz ELTs and PLBs. Some PLBs ARE 406mhz and have to meet the same specifications, including wattage and terminal homing requirements. Other PLBs, such as SPOT and In-Reach, have far less wattage (less chance of reaching the Sat) and do not go directly to the NOAA SARSAT, instead, they use 3rd parties to contact the regional rescue coordination center. This could be important in areas with poor signal transmission, like under canopy or with high-angle terrain. The terminal homing is still used by rescue personnel, even when GPS coordinates are given. This is not necessarily all bad in terms of PLBs, but you should know what you are getting and what the capabilities are. The ability to send a message may be a nice thing to have. For personal use, I have both a 406mhz PLB and an In-Reach. The 406 is more of the “press this button for the worst case scenario when you want to be found”. You can register devices now with FSS (at least here in Alaska) that will provide tracking and a feature for them to look back at, should you not reach your destination. No one is actively watching this though, in the sense that an ELT would theoretically be immediate at impact. And of course there’s the impact, which has proven to be problematic for G-triggered ELTs, not activating when it appears they should. But your personal PLB likely has no such function.

    • In the interests of clear discussion, i believe that SPOT and InReach devices are “satellite messengers”, a different category than “Personal Locator Beacons” (PLBs). I believe that the PLB definition includes a 406MHz transmitter of digital emergency data. It’s not just a matter of “some PLBs are”. And the “satellite messengers” are not PLBs, they don’t use the same frequency or digital emergency data format or usage model. They can operate as trackers, sending out a message with your position and speed every few minutes, as well as sending messages from in the bush. The 3rd parties are supposed to monitor the tracking messages, and respond when the messages stop. Thus when trackers fail, the system recognises this as a potential emergency; but when PLBs fail, the system is oblivious.

      • I would consider SPOT and In-reach to be PLBs, in that they have “SOS” functions that send position data. Spider-tracks has this function too. The difference is it has to go through a commercial satellite (often iridium network) and organization to get to the RCC. They also operate at far less watts and typically don’t have the terminal homing function. But as far as basic “SOS” function, they do have this and as long as you have an active subscription, it should trigger the RCC. A 406 on the other hand is a more direct channel to this with more probability of being successful. No one is “monitoring” your track though on a SPOT or In-reach, unless you have friends/family doing so. I’ve used these myself. FSS can look it up if you registered the device and failed to close your flight plan, but that’s not immediate, like if you crash 1hr into your 3 hour flight, they are only looking at if you arrive at the destination 3 hours later and if you didn’t, then they’ll look at the tracking.

  18. It seems to me that, in the days of smart electronics, there should be an easy way to eliminate most false alarms from ELTs. The new 406 units normally have a panel-mounted test/activation switch and an option to wire it to the plane’s GPS device. Some of the more expensive units have a built-in GPS sensor. In either case, is should be easy to program the ELT to only become active if the airplane is in motion, and activate if the speed drops to zero within a short time period. In a normal landing, the airplane’s velocity drops gradually, not within a second or two. That would obviously require all old 121.5 ELTs to be replaced, so as Paul suggests, dumping the ELT altogether and relying on ADS-B, cell phones, PLBs or In-Reach type devices makes much better sense. Cheaper too.

  19. I flew a CAP SAR mission last October that found a downed aircraft in the Mark Twain national forest in south central Missouri less than 5 hours after the accident and one hour after we launched, and the primary tool used was homing on the 406 MHz/121.5 MHz ELT signal. The aircraft was in dense woods, several miles from the nearest small town, and cell phone connectivity was probably nonexistent. The aircraft was invisible except from directly overhead, and also not visible from the nearest road that was only 115 yards away. The pilot was incapacitated, so triggering a PLB would probably not have occurred. Given the dense woods, the aircraft wasn’t visible from much more than 20-30 yards away, so a ground search that didn’t have precise coordinates to head to would have taken hours longer. Seeing the efficacy of the ELT convinced me to upgrade my 121.5 MHz ELT to a 406 MHz ELT. I’ve more recently done two 121.5 MHz ELT searches for ELTs that activated due to aged out batteries or installation errors, and you can expect hours of delay before the CAP is activated to go after one of those, since 121.5 is no longer satellite monitored.

  20. Regarding my SAR mission last October, ADS-B was also ineffective as both the aircraft we were searching for and our own C-182 G1000 dropped off of ADS-B tracking about 20-30 miles north of the crash site due to our low altitude (1000-2000′ AGL).

  21. As Paul suggests, an ELT is useful for CFIT (terrain) in the mountains, but CFIT (towers) in the flat lands. Can’t activate a PLB in those moments.

  22. In Canada there is a requirement to file a flight plan for any flight not in the vicinity of an airport OR provide a flight “itinerary” with a responsible person. Which seems like a good idea anywhere so even if I’m just out tooling around I try to always let someone know approximately when and where, and check in with a quick text upon landing. I figure with that and ADS-B out, ELT is redundant and unnecessary. I would support the notion that with a SATNAV device the ELT requirement should be waved.

    • Can you imagine the outcry if the FAA were to put out a restriction like that to VFR flying in the US? Another reason why I think making the comparison to Canadian rules could come back to bite VFR flyers in the behind.

      • Sorry I wasn’t suggesting the US adopt that rule. Just saying for my own safety, telling someone where I’m going makes sense and along with the ADS-B makes ELT superfluous.

        And in fact when I first read the Canadian rule I went “what?!” but really telling someone (anyone) where you think you’ll be going is an easy out and makes more sense in most cases than filing flight plans.

  23. You piqued my interest and wondering about MH370. A CNN article stated there were four ELT’s aboard; one primary plus a stowed extra plus two water activated units in life rafts. It also talked about the fact that it takes ~50 seconds for a 406 ELT to send out a data burst indicating there’s an emergency activation but about six bursts 50 seconds apart for the six high altitude COSPAS-SARSAT geosynchronous and six low altitude non-geosynchronous meteorological satellites to determine a position with a CEP of ~2 miles unless position is encoded into the data burst. So unless you’re providing your 406 ELT with GPS position, it isn’t all that more useful. And if a water crash is involved, things are worse still. They don’t work underwater.

    IMHO, where all of this is headed is a satellite based ADS-B system which “sees” all aircraft in flight. I have no idea what conversion of existing ADS-B systems to dual diversity might cost but if every aircraft was constantly reporting in to a satellite, problem solved. ELT’s no longer required. Sooner or later, some FAA bean counter will start comparing the cost of maintaining 650 ground stations with a hand full of geosynchronous satellites and a ‘new’ ADS-B requirement will pop out. Non-electrical aircraft or those without ADS-B would still need the ELT. Now that I think about it, the ADS-B out box I installed in my airplane uses software derived on ground / in air flying transitions. Why couldn’t a 406 ELT section be added which used rate-of-change of airspeed along with a MEMS device to determine an unusual attitude. One burst of digital data might say … “something bad just happened here.”

    Being still another “CPB,” I reuse the D cells in my E-01 in my inspection flashlight. THAT is the beauty of that system. Chisels, hammers, welding torches, grinders and other implements of destruction not required. But if I had the orange 406 version … bring $170 please.

    • The specifications of ADS-b Out 978 Mhz. is designed for 250 miles line-of-sight. With this range it is very likely the signal is being picked up by satellites already and used. The internationally required 1090ES Mhz. ADS-b/Mode-s signal is mostly satellite based according to their literature.

      The technology of sending auto text to cell phones of the pilot’s choice is available now. Every time the In-Reach accelerates over and less than 35 knots an auto text is sent to the concerned parties cell phone. The software for this automated texting service is in the internet servers. I use this service for aircraft that fly in the far north of Alaska and Australia. Sometimes the pilot forgets to turn the feature off while driving through town and I text them back to turn it off.

      If Flight MH370 had the texting service in use it would have sent a text to the airlines’ dispatch. The text would have immediately transmitted the coordinates to the dispatcher were the satellite link has been disrupted. Aircraft in the area would have been able to respond through radar, visual and radio communications.

  24. I agree.
    The next thing that should sunset is the Baro altutude. The GPS is more than sufficient and we don’t need to do those silly transponder and encoder tests anymore with our gee-whiz ADSB out replacing it so well.

  25. If one were to launch an aviation universe “from scratch,” it likely would NOT include 90% of existing mandated technologies and rules.
    It likely would not include the FAA, either.

  26. Yars has the best line on the subject! If you had to design a system “from scratch”–it wouldn’t look like this convoluted mess of 121.5 transmitters, 406 units, depending on someone monitoring and hearing it on guard frequency–or satellite monitoring (all depending on whether it survived a crash)–then contacting search and rescue.

    LOOK at the expense of the equipment–the maintenance of the equipment–the monitoring–and the searching. For the money spent on maintaining this hodgepodge system, the FAA could GIVE a unit to every aircraft owner (or every pilot, for that matter) and scrap the rest of the expense–saving taxpayer money.

    Since the FAA is more about “control” than “safety”–how about this–when the aircraft owner renews his aircraft registration, he exchanges his locator for a new one–the FAA finally would know just how many aircraft actually use the system (CPB often don’t even renew registrations).

    For the hundreds of millions of dollars the FAA spends every year on “research” (my favorite was the hydroplaning tests at NAFEC for the past 59 years–how much do you continue to learn about hydroplaning a Boeing 720B–the only one left flying? With that money spent on “research”, they could afford to GIVE a new GPS to every aircraft owner in the country–then the next year, the ADS-B–then the next year a fuel computer–and the next year an autopilot……….(example– spending billions of dollars and a decade on a land-based ADS-B system that aircraft owners and the rest of the world doesn’t want.

    • Now that the ADS-B equipage deadline has passed, how long do you think it will be before the Agency decides that we all really need to equip with diversity antennae (and transceivers), to take advantage of… wait for it… satellite ADS-B?

      Sometimes (often) I think that these “experts” could throw a football from the observation tower of the Empire State building – and miss the ground.

      • Quiet Yars!! Don’t give them any ideas.

        Seriously though, I am willing to bet that they will start the diversity push in less than five years. The Canadians came up with a better idea than the FAA (big surprise) so now they have to come up with a new toy to avoid looking (more) stupid. I knew I should have waited for the Tail Beacon to equip for ADS-B.

  27. Some of us actually do like and use ADS-B. The “In” part is particularly useful, for both traffic (I find it generally more precise in locating nearby traffic than ATC call-outs) and weather. Especially for a flying club where equipping all of the aircraft with SXM weather would be cost-prohibitive.

    If converting our existing ADS-B installation to diversity that can work with satellites could be done for about the cost of a 406 ELT, and could be substituted for the ELT, I would be all for that. If the “In” part could work off of that too, even better. I would make this optional, and get rid of the existing ELT rule and put in place a rule that lets you remove the ELT if you have an ADS-B w/ satellite diversity installation, or for 6 seats or less for Part 91 operations you don’t need one at all if you carry a PLB (and only to keep the congress people happy).

  28. The U.S. will eventually have to change to the “diversity” beacon, as the rest of the world has adopted it. Even if there is a way to keep the FAA ADS-B, there will have to be a “patch” to make it work with the space-based system–as well as the need for a top-mounted antenna.

    The “tower-based” system was a loser from the very first–but the FAA wouldn’t admit it. They were replacing one “line of sight” system (radar) with ANOTHER “line of sight system” (towers). Both systems don’t work unless you are within reach of a tower, and ADS-B doesn’t give weather information unless within range either.

    Is it any WONDER that the Russians rejected the U.S. system in their sparsely populated areas? Is it any wonder that Canada (and the rest of the world) rejected the system as unworkable? The Russians developed the system and launched the satellites in record time compared to the U.S. system. As it is–there aren’t many countries in the world where the U.S. system works. And then there is the whole “978” system–most GA airplanes have that system–Canada and Mexico are still on the fence on whether they will build that system into their networks.

    Given the cost over-runs–the limited benefits to the ATC system compared to radar–the long time to implement the system–the cost to consumers–IF THIS SYSTEM HAD BEEN BROUGHT OUT BY A CORPORATION INSTEAD OF THE GOVERNMENT, IT WOULD BE INDICTED FOR FRAUD. Once again, it would have been cheaper for the government (let alone aircraft owners) for the FAA to skip the billions of dollars on development of the system and simply GIVEN each aircraft owner a compliant system. Think about it–even if it cost 1 billion dollars, divided by 250,000 aircraft, that would be $4000 per aircraft. Certainly, there would be an economy of scale in a contract for that many units–I’m sure the program would have cost less than the FAA method.

    • I think your editorial style could do with a makeover, Paul. Where I come from Sunset is not a verb.
      Half-assed, and terms such as you never know thinking, are vague journalistic expressions when referring to serious topics.
      I have read the Embry Riddle thesis, which is both well stated and thorough. I support the case for ELT installations, given the circumstances described in the thesis.

      There is a case for plain English in safety matters. In my experience, flight safety was never referred to in colloquial or ambiguous terms. In aviation, we all like plain-speaking English, which should always both precise and concise.

  29. While I agree with Paul that it is time to sunset the ELT requirement and make it optional. The old 121.5 MHz system was riddled with false transmissions (like hard landings), low reliability such as not activating properly during a crash (example Steve Fossett) or if the antenna was broken off or the airplane flipped on its back.
    Additional considerations:
    1. While an ELT is currently required, a 406 MHz ELT is not required, much less one that also transmits LAT/LON.
    2. As a CAP member, yes, we have a lot less ELT missions. I wonder how many of 900 yearly CAP ELT missions were due to EPRIBs (at least in Florida). Most EPIRBs were in marinas, now with 406 MHz EPRIBs, all that is required is to call the telephone number(s) associated with the offending EPIRB. And no need to wake up at 2:00 AM.
    3. While a 406 MHz ELTs also has a 121.5 MHz analog signal, it is very weak and only useful close up-within one mile. CAP members typically don’t have VHF Direction Finding equipment. Also, you cannot home on a digital 406 MHz burst. That is perhaps another reason for the lower number of ELT missions. We simply cannot home on them. New CAP aircraft no longer come with DF.
    4. With the old 121.5 ELTs, satellites had to make several passes to provide a rough estimate of location by triangulation using the doppler effect. That is no longer true with 406 MHz ELTs, one or two quick digital bursts is all it takes. Twice during an annual, within minutes of activating my LAT/LON 406 MHz ELT, I got a call from the Air Force Rescue Coordination Center (AFRCC) at Tyndall Air Force Base (FL) telling me that my ELT was going off on the SW corner of my airport. Opps, time to call the shop.
    5. Because the 406 MHz ELTs, PLBs, EPRIBs have to be registered (NOAA in the US), it is easy to identify the vehicle and person(s) associated with the unit. All it takes is a phone call or two.
    6. I would not count on “bread crumbs” left by a moving cell phone for SAR especially when flying over more remote areas, even places closer to home like the Everglades. It’s all about cell or lack of cell coverage. On the other hand, if flying over Manhattan, then it would be hard to crash without no one noticing.
    7. Yes, with Flight Aware, etc. easy to see where an airplane has been. But you are missing an important point: someone on the ground must advise the AFRCC that an airplane is missing. ATC can do that if on a flight plan. Not necessarily so with flight following without a flight plan. Or it could be a friend or family member that alerts someone: “Billy did not come home yesterday after he went flying”.
    I think the answer is:
    1. Make an ELT optional with preferable one that also transmits LAT/LON. After all, even when flying from Florida to the Bahamas, Part 91 operators don’t need flotation equipment.
    2. If an airplane has a 121.5 ELT, remove it. Save the weight, it is useless. No one is going to hear it.
    3. Change the procedure on how ELTs are activated. All 406 MHz ELTs need a switch on the panel (not true with the older 121.5 MHz ELTs). In case of an eminent off-airport landing, activate it in flight. Don’t depend on high G forces to activate the ELT. All it takes is a couple of bursts and “they” got you. No need to depend on VHF communications nor squawking 7700. In fact, passengers should be briefed about activating the ELT in flight and on the ground. Granted, this will not help in mid-air collisions nor CFITs.

    • “2. If an airplane has a 121.5 ELT, remove it. Save the weight, it is useless. No one is going to hear it.”

      This is not what the NTSB data show, actually. For the five year study I did ending with 2017 data, 406 ELTs aided in 12 accidents and did not aid in 17. For the 121.5 ELTs, they aided in 11 and did not aid in 17. Pretty much the same performance and all after the 2009 end of 121.6 satellite monitoring.

      The ERAU study found that mean search times for 121.5 ELTs was 12.8 hours and 11.8 hours for 406s. For 406s with GPS, it was two hours.

      This supports my point that overall, the 406 idea has not performed much better than the 121.5 system. Several SAR pilots told me they had trouble locating 406s because you can’t home on the pulse. Some were never found. So if you get a 406 ELT, add the GPS option if you expect much out of it.

      • Let me correct what I said regarding 121.5 only ELTs. “No one is going to hear it”. I should have said, “even if heard, no one is going to find it through homing”. New CAP airplanes don’t have 121.5 DF and few CAP members have working DF equipment. (Mine died years ago.) At times when I tune 121.5 while flying, I hear 121.5 ELTs. I do tell ATC but they cannot do much about it since the location is very vague – somewhere say in S Florida – thousands of square miles.

        I’m sure the stats that you quote are correct, but is the 121.5 data also during the same time period 2012-2017? Are we doing a apples to apples comparison? Let’s be clear, if you are on a flight plan (VFR or IFR), ATC will sound the alarm. If you always file a flight plan even for local flights, then a working ELT is not that useful.

        The weakest aspect of your stat analysis is that you are ascribing the success (or not) of finding an airplane to 121.5 vs. 406. It is the classical problem in cause & effect analysis by looking at only one factor – type of ELT. Most likely there would many confounding factors to explain the success of finding a crash.

        My main point is: If you have a 406 MHz ELT, then you should be willing to activate it in flight. It will be heard after a few digital bursts. If you are not willing to activate it in flight, then keep the useless 121.5 ELT since it is still mandated by the regs. Then rip it out when the FAA makes ELTs optional.

        Just hope that: 1. some one calls to report a “missing aircraft” and 2. that your cell phone provides good enough bread crumbs to find you.

        • Are we doing a apples to apples comparison?

          Not really. We’re doing the best-data-available comparison and the data is just not very good. So the question to be answered is: how often does an ELT aid in crash location? Irrespective of ELT type, best case appears to be 50 percent. There’s no data that appears to improve that, at least that I can find.

          As for 121.5 tracking, CAP’s director of ops, John Desmarais told me CAP still has the equipment to locate 121.5 signals and is in the process of finding a new source for upgraded gear. They can also process the hexadecimal 406 signals including, if I’m not mistaken, the position sentence.

          Point of all this is that 406 has not lived up the promise of being a markedly better technology. It is, at best, marginally better. When it works…

          • MMMMM . ..  I don’t doubt your conclusion that 406MHz has not lived up to the promise; however, I don’t know when and who made that promise since it had worldwide support.   

            Regarding CAP’s DF capabilities.   

            1.   Most handheld DF equipment is/was owned and paid by individual CAP members.  Most don’t work and usually are not repairable. I believe that by now the manufacturer (L-Tronics) is out of business. L-Tronics produced both hand held and airborne units.  I do know that several years ago they couldn’t fix my DF equipment. A newer manufacturer emerged: Becker with its unit SAR DF-517. Not sure if still is in production.
            2.   Older CAP airplanes do have 121.5 only DF equipment that may or may not work. Some have the newer Becker units. These DFinders are getting scarce given that new CAP C172 and C182 airplanes don’t have DF equipment.
            3.   While CAP HQ in Alabama (or elsewhere) might be able to decode the hexadecimal code, field members cannot.  However, logically it does not make sense since CAP does not receive the transmissions.  So, whoever receives the transmission (NOAA, the satellites company, AFRCC?) is or should be the decoder.  In the past, the AFRCC would provide CAP with the information of the area where the 121.5 signal was located. Given the imprecise triangulation method using the doppler effect of several satellite passeswith the old satellite system (pre 2009) the coordinates usually covered a very large area and were practically useless. Hundreds of square miles.
            4.   However, let’s assume that we have the LAT/LON coordinates of a 406 MHz transmitter, we may still not be able to find it because of lack of DF capability.
            5.   Lastly, while the 406 MHz ELTs also transmit an analog 121.5 MHz signal, it is very weak. Homing on that the signal is not practical unless within less than a mile and that is being generous. However, if an ELT goes off (both 121.5 and 121.5/406) at an airport, itis relatively easy to find it using an aviation handheld tuned to 121.5 MHz using the body null method. Since most pilots carry an aviation handheld in their flight bags, maybe some guidance for pilots on how to do the body null method might be warranted, at least to track down activations at airports.  Additionally, it is a good practice to tune 121.5 MHz after landing to confirm that the ELT was not activated by mistake. 

  30. I’ve been using inReach notification for over six years but, after posting about what ADS-b should be able to do… I did a little research and found out what it can do.

    If you are interested in real time notification on the Cheap (CPB). does offer Automated Cell Phone Texting of any registration number (your choice). Each time the registration number w/ADS-b enters the service area you will receive a text. Every time the ADS-b signal is discontinued or the aircraft lands and shuts down, you receive a text. My cell phone has been beepin’ all day. I work for a very busy 135 charter outfit.

    First create an account and register with Then go to the ‘Flight Alerts’ tab and add up to 5 aircraft registration numbers for “FREE”. You’ll be asked to set up your cell phone’s text email address, fortunately it gives instructions how to do that. Set the parameters you desire. Then each time that aircraft enters and departs the ADS-b service area you will be texted. I don’t think “texted” should be a word but you get the point.

    Next time Grandpa takes his RV-8 or Super Cub out for a spin and you get a text that his signal discontinued in the middle of nowhere. Go to your favorite ‘Flight Tracking’ website and type in the registration number. You may be the first person to know that Grandpa needs assistance?!?! If you call and don’t get an answer start calling people that can help. This is how ‘search and rescue’ is done in the digital age. Remember he named you as the beneficiary.

  31. Thank you Paul and Klaus, very good info for me I was not really aware of. Flying the inter-mountain west I have my usual airways, but added knowledge is added freedom.