406MHz ELT - Fast Facts

Hi Folks,

Seems that ELT's are a hotly debated topic around here. The intent of this topic is not to add fuel to the fire, but rather to share some factual information that I hope will help folks who are going to purchase an ELT. A recent thread on a "cheap 406MHz ELT" contained some information which might be misleading and could potentially lead to one of us not getting what we expected in a purchase transaction. Since nobody needs this kind of hassle in their lives I thought I'd get some of the facts out on the table in hopes ELT buyers will become better educated consumers.

Firstly, let's talk TSO's (technical standards orders). A piece of avionics gear that meets a particular TSO in fact meets a specific set of design and performance characteristics, as defined in the TSO document. In the case of ELT's there are three TSO's that commonly apply:
1) TSO C91
2) TSO C91a
3) TSO C126

Of these TSO's, C91 is the oldest, the original. I don't know about other jurisdictions but I do know in Canada it is no longer legal to do a new installation of a C91 ELT, so even if you were to purchase a used one it would be illegal to install it in your spanky new RV.

After it became evident that TSO C91 wasn't providing the operation performance that was originally intended, a revision was issued in the form of TSO C91a. This spec featured improved performance requirements, including advances in crashworthiness, reliability of operation, and frequency stability. The marketplace is currently well populated with TSO C91a units made by a variety of manufacturers - these are what we commonly refer to as 121.5/243.0MHz ELTs.

TSO C126 is the newest spec for ELTs, and in fact is the TSO which deals with 406MHz ELT's. Neither C91 or C91a units emit on 406MHz, period. This was the bit of factual information that was incorrect in a previous thread. If you want a 406MHz ELT, it MUST meet TSO C-126. All TSO C126 MHz ELT's also broadcast on 121.5MHz so that SAR resources and overflying commercial flights can still use this signal to home in upon.

Now for another little bit of info... The TSO certification process requires the manufacturer to certify their equipment as an operational group. That means that certification testing is carried out with a specific ELT, external "buzzer" (if necessary), antenna(s) and cockpit control unit. For us on the buying/installing side of the equation, what this means is that we can't "mix and match" compenents. That means no home-brew antennas, no re-use of your existing cockpit controller (unless the manufacturer specifically indicates in their installation manual that the part number you have is approved for use with the new C126 ELT). It also means that you need to install the new ELT in accordance with its approved installation manual - re-use of "existing" installation components may not meet the TSO requirement. While those of us who are building/flying "experimentals" don't necessarily need to meet TSO like the "certificated" boys do, it is a very wise idea to stick to the TSO requirements when it comes to this piece of life-saving gear.

Here's the final tidbit of data that is vital to those intent on purchasing a 406MHz ELT. These things are not cookie cutter "one size fits all" like the old TSO C91 and C91a units. Each jurisdiction dictates how the C126 ELT should be programmed. Some of the variables include country coding, whether the unit needs to transmit tail number or 24-bit ICAO code (Mode S address), or any one or combination of a few other choices. This being the case the TSO C126 ELT is essentially a device dedicated to a single aircraft ( for instance, my 406MHz ELT needed to be coded with my ICAO code for use in Canada). When purchasing an ELT you will need to understand what your unique national requirements are and be able to provide the ELT vendor with the appropriate information so as to ensure the ELT is properly coded prior to its delivery to you. Additionally, many jurisdictions mandate specific certification requirements, so while a vendor may offer a TSO C126 ELT for sale, it may not be approved for use in your particular jurisdiction, so caveat emptor!

I hope the info relayed here will be of help to those who are ELT shopping. Once again I will stress this isn't intended to be fuel for any kind of debate about the usefulness or need for ELT's, but rather is intended solely as a communication of facts to help ELT buyers become more educated and thus avoid some common pitfalls.

Good Post Mark.

Complete and correct.

Great post! Thanks for the detailed info. As I was reading the post, my mind started to wander...as it often does.

Lets assume that I have one of these new TSO'd 406MHz ELT installed. Can I complete my annual / condition inspection by just verifying that the ELT transmits on 121.5MHz, using my in-aircraft com receiver?

Or, do I need to find a 406MHz receiver to verify that a "proper" signal is being sent?

Do I also need to verify that the correct tail number is imbeded in the ELT's data stream (or ICAO information), and GPS co-ordinates if supplied??

I really have no answers as to what I might be able to verify, but as I stated earlier, my mind tends to wander...

Dynon - others, are you interested?

It would be good if Dynon and other manufacturers would be interested in this up-coming market. Given the quality of the Dynon and other companies that are on the cutting edge of experimental cockpit instrumentaion, it would be good for those who are flying them to have a choice in manufacturer.

Which brings up the question of how difficult and costly it is to manufacture, certify, and sell these. I assume that there is some sort of certification required? for each unit or type? Your thoughts -----

One set of instructions here...

noelf said:

Great post! Thanks for the detailed info. As I was reading the post, my mind started to wander...as it often does.

Lets assume that I have one of these new TSO'd 406MHz ELT installed. Can I complete my annual / condition inspection by just verifying that the ELT transmits on 121.5MHz, using my in-aircraft com receiver?

Or, do I need to find a 406MHz receiver to verify that a "proper" signal is being sent?

Do I also need to verify that the correct tail number is imbeded in the ELT's data stream (or ICAO information), and GPS co-ordinates if supplied??

I really have no answers as to what I might be able to verify, but as I stated earlier, my mind tends to wander...

Click to expand...

The Artex testing/annual requirements are here...

http://www.artex.net/documents/getFile.php?fileid=314&filename=570-1600_Manual.pdf

.....and are quite similar to the present C-91a stuff. I would think other vendors would be similar.

However, our friends North of the border (..eh) have a much more difficult time, and must have a certified shop do checks.... Also detailed in the above link.

gil A - in Colorado Springs, and noticing if the Pikes Peak railway engineer (driver?) was a pilot, he would need oxygen (14,110 ft)

Gil - right on all counts, and thanks for chiming in with this good reference.

Unfortunately, since I'm one of those folks "north of the border" I get to do the full annual recertification which requires a screen room and a spectrum analyzer. This gets expensive for C91a ELT's (cheapest annual recert costs about $50 by the time the unit is back in your hands), but is an even more expensive adventure for 406MHz ELT's. So far the best quote I've received for recertifying my Artex ME406 ELT is about $130. Still, my hide is worth a little more than that to me if kept in one piece, so I'll be shelling out the cash. As the old saying goes, if you've got a ten dollar head, wear a ten dollar hat! ;-)

One positive development that's come along with TSO C126 is that ELT's conforming to this spec must have an audible alerting device that confirms ELT operation. This means that after you've made a less-than-stellar landing and have shut down (while letting your blood pressure return to normal *wink wink*) the chirping of the ELT's audible alerting device will confirm your worst fears. If you hear it chirping that really was a bad landing, one that should be measured not on a linear scale of 1 to 10, but rather on the Richter scale!

Mr. Eliot - to answer your question, yes, there's a fair bit involved in bringing a 406MHz ELT to market. Testing needs to be done first to satisfy Cospas/Sarsat that the unit meets their requirements. Then you need to do the full TSO testing (hot, cold, shock, vibration, sustained G, flammability, explosive environment, salt spray, etc etc etc) which can burn up a hundred grand in the blink of an eye. Then you need individual national regulatory bodies to give their approval. As an example, in Canada, first you have to have Transport Canada agree the unit meets both TSO C126 requirements and the requirements unique to Canada as detailed in the CARs, then you need to have Industry Canada approve the device as a radio emitter, and once these two approvals are in hand you have to go back to Transport Canada to ensure they have received the Industry Canada approval and once that is done you have to ensure Transport actually lists your ELT on their list of approved ELT's. Since I was one of the "interested parties" involved in getting the ME406 approved in Canada I can assure you this process takes time and patience. Other nations present similar certification challenges.

Given these certification challenges, plus the requirement for each unit to be programmed for each specific aircraft (the folks who do the programming need to make a bit of money on that transaction) I don't believe it's reasonable to expect 406MHz ELT's to ever be as cheap as the current TSO C91a ELT's.

I fly behind a Dynon EFIS and enjoy it immensely, but suspect that even their innovative approach to avionics design would not result in either a vastly superior or vastly cheaper end product.

406MHz ELT - (not So) Fast Facts

Very nice write up! Lots of good detail.

Canadian_JOY said:

Hi Folks,
It also means that you need to install the new ELT in accordance with its approved installation manual - re-use of "existing" installation components may not meet the TSO requirement. While those of us who are building/flying "experimentals" don't necessarily need to meet TSO like the "certificated" boys do, it is a very wise idea to stick to the TSO requirements when it comes to this piece of life-saving gear.

Click to expand...

The new 406Mhz freq ELT antenna will be small (high freq, short wave length, short antenna). Some manufactures will have one antenna for both Freqs (121.5/406 Mhz) the size of existing 121.5/243 Mhz antennas, like an Artex ME406. Others will use have two separate antenna, like the 406 EBC, one small 406 Mhz antenna and one longer for 243 Mhz.

I agree with what you say, but Builder/Pilots like to make their own hidden antenna installations which does not read right out of the TSO installation instructions. That trend with home builders will continue no doubt with the newer 406 ELTS. Whether it's OK or not from a regulation stand point is up for debate.

Each jurisdiction dictates how the C126 ELT should be programmed. Some of the variables include country coding, whether the unit needs to transmit tail number or 24-bit ICAO code (Mode S address), or any one or combination of a few other choices. This being the case the TSO C126 ELT is essentially a device dedicated to a single aircraft ( for instance, my 406MHz ELT needed to be coded with my ICAO code for use in Canada). When purchasing an ELT you will need to understand what your unique national requirements are and be able to provide the ELT vendor with the appropriate information so as to ensure the ELT is properly coded prior to its delivery to you. Additionally, many jurisdictions mandate specific certification requirements, so while a vendor may offer a TSO C126 ELT for sale, it may not be approved for use in your particular jurisdiction, so caveat emperor!

Click to expand...

Another case of a country setting their own unique requirements is Canada and their batteries. There was lots of confusion about this.

"The battery must not be LiSO2 and, for a 406 ELT, it must be coded for Canada and registered with the National Search and Rescue Secretariat."

It must be coded for Canada ONLY if your plane is registered in Canada. The battery issue was a separate deal. The New Artex ME406 was originally approved with a battery that Canada did not allow. So even a USA registered aircraft could not use the ELT (in theory) to fly into Canada due to the battery type. Artex made the change and re-certified to a new type of battery chemistry, to satisfy Canada rules. Even though the Artex ME406 ELT met all TSO's (C91C and C126), Canada implied they would not allow flight into their country with this ELT? Well its moot now, because Artex acted fast and got the change made. All new ME406's are good to go in North America.

The sticker on the ELT saying Canada approved? If you have an older ME406 and switch to the new battery you should be fine, but Artex change the ID tag for "conversion" to USA & Canada ops. Now that Artex made the change there's no problem using their ME406 USA ELT in Canada for USA registered planes.


*************************************************

You mention country code. The key is where the plane is registered or its N number. It has to match the ELT. As far as buying an ELT for Canada in the USA, some vendors in the USA will be able to flash the unit for Canada code as you say. Some US distributors have Canada coded ELTS stock on the shelf.

The country code makes sense. When a beacon signal is received, they first contact the country of register so they can make the calls and find if its valid. Even if the signal is coming from Iceland, they will call Miami or Vancouver BC first, if that's where the plane is registered.

Not only are country codes unique, many countries want and got their own unique requirements for the info to be transmitted, in addition to the country code. Its a digital signal so it can be programed to send unique digital streams. It's a pain for the ELT makers, but some countries wanted to be unique. So as you say be aware. I guess the world could not agree on the signal to be sent. The 406 Mhz system is an international deal. Its has lots of Cook's in the kitchen and not all agree. Just be glad we only have to deal primarily with USA/Canada issue. Europe is worse with uniformity and reciprocity.

(PS I think Airtex allows you to use your old Artex panel switch indicator for their new ME406 ELT, I could be wrong)

ELT Education

Thanks to you all for the ELT education. It'll make it a little easier to pay the asking price when the time comes in a few years (for me). This technology seems to be a great improvement over the current system - hope that it really works in saving lives, etc. Thanks again.

Canadian_JOY said:

In the case of ELT's there are three TSO's that commonly apply:
1) TSO C91
2) TSO C91a
3) TSO C126

Click to expand...

And what I found is that prices well follow the standards. The older ELTs are practically free while C126 seems to cost from $1000 upwards. I doubt the technology is that different but rather there are just few manufacturers so easy to ask whatever they like...

Prices

At least in this thread, no one has mentioned that the satellites are going to stop monitoring 121.5 MHz next January. So your $180 ELT will be a nice paperweight.

I've seen the 406 MHz ELTs as low as the $800 range, and they will only go lower. I've already got mine. Trying to save a few hundred bucks on a less-effective ELT seems like "penny wise, pound foolish."

TDT

yooper said:

At least in this thread, no one has mentioned that the satellites are going to stop monitoring 121.5 MHz next January. So your $180 ELT will be a nice paperweight.

I've seen the 406 MHz ELTs as low as the $800 range, and they will only go lower. I've already got mine. Trying to save a few hundred bucks on a less-effective ELT seems like "penny wise, pound foolish."

TDT

Click to expand...

This was the reply I received last year on the matter:

We shall manufacture the ELT 406 MHz in the next few months. We are now at the last step of FAA TSO Certification stage for ELT 406 MHz P/N AK-451.
However, we have been contact with the FAA almost everyday and confirmed that there will not be any requirement from the FAA about ELT 406 MHz
in 2008, 2009. May be there are strong opposition from AOPA.

The requirement of ELT 406.0 MHz will be for the Marine only in 2009. The Military Satellites of 121.0/243.0 MHz will be available after 2009 for sure.

The new ELT 406.0 MHz P/N AK-451 shall be the same footprint and size as our ELT AK-450 for easy retrofit direct replacement. We also have a program of exchange to ELT 406.0 MHz P/N AK-451 and credit to your old ELT AK-450.

Please accept our sincere appreciation for your interest in AMERI-KING'S products. I'll look forward to hearing from you soon.

BEST REGARDS,


VICTOR VAN
SALES MANAGER
AMERI-KING CORP.

It seems clear that while some satellites may not be monitoring 121.5, lots of aircraft and ATC facilities will. I personally think TC has rushed this in way too fast and many manufacturers still don't have their 406 models approved yet.

rv6ejguy said:

I personally think TC has rushed this in way too fast and many manufacturers still don't have their 406 models approved yet.

Click to expand...

I wasn't aware that Transport Canada had actually published a regulation requiring 406 ELTs. There was lots of opposition to their draft regulation, and I thought that the matter was still being discussed, with no published reg yet. Did I miss something?

yooper said:

... So your $180 ELT will be a nice paperweight...

Click to expand...

I think paperweight may be a bit strong a word. 121.5 ELTs have proven to be of marginal usefulness, but many aircraft have been found faster because of them. This was true in the days before satellite monitoring as it will be true after those days. There are other ways of homing in on ELTs than satellites.

and what about 406 ?

Larry has brought up a great point. ELTs have historically been "marginal" at working in an accident. What assurance do we have that the 406 units will work any better ?

I am starting to wonder if this is a case of creating a modern version of a 1950 solution. Maybe we need a different solution. Maybe the solution is to transmit position(spot/tracker etc.) and use standard technology to do it. We are no longer the only ones interesting in being found in an emergency. Is a hiker or boaters life somehow worth less than an Aviator ? Do we really need a heavyweight "aviation specific" solution to what is now a more general problem ?

John

TC was about to force feed us with the 406 solution initially disregarding input from COPA and others, then stepped back a bit with some time concessions to implement. You are right Kevin, not written into law yet but it is certainly coming soon- hopefully with some more sensible timetables and applications for private owners.

If the primary triggering is still the G switch used in 121.5 models, I think their usefulness may be only slightly better than the old models when many fail to activate. This is the sort of detail that should be considered long before we are forced to install expensive and barely better devices on a short timetable. The 406 units will certainly get you found sooner than the older ELTs IF they activate.

Just to throw a word or two in edge-wise...

My original intent with this thread was to discuss the facts of modern ELT's, not whether or not those ELT's are necessary or useful. It seems that any discussion on ELT's eventually wanders off into the tall weeds of "why do we need ELT's". That set of questions has been hashed over more than enough in other threads. Please, let's not go there with this one.

So, back to the original intent...

An earlier poster mentioned that some 406MHz ELT's from Artex may be able to make use of the remote control unit from previous Artex TSO C91a ELT's. This is indeed the case - with specific part numbers being listed as approved for use. That means some folks will be lucky enough not to have to do very much modification to their aircraft when upgrading from a TSO C91a to a TSO C126 ELT. Let's hope other manufacturers follow this path of backwards compatibility with their products!

Other very valid points were raised in previous posts and warrant emphasis. The country of registration of the aircraft determines requirements for both ELT installation and ELT coding. Some countries require only proper country coding, while others, like Canada, require use of the 24-bit ICAO (Mode S) code, meaning each ELT is uniquely coded for a particular aircraft. This truly is a case where we as consumers need to inform ourselves of the requirements unique to our country of registry and ensure the equipment we purchase meets those requirements.

Am I dense....

I'd like to understand the requirements for an American Experimental to fly into Canada. I've read these posts and am still confused.....

The way the gov't is talking right now NO aircraft will be allowed to fly in Canada from the USA without an ELT on 406mhz. I think they are nuts and won't be able to enforce it. It won't matter if it is certified or homebuilt. We will just have to wait and see what really happens when the time comes. They haven't even made it a law yet. It is still in the law makers hands. Until it is is published in the gazette it is not law. They are talking a two year grace period to get everyone on board. When it becomes law. They have spent enough money now advertising that we will need 406 ELT's with posters and sticky labels etc that they could have bought the entire GA fleet in Canada an ELT!

TSO91-TSO91A-TSO126

Hello
Sorry if I beat the hornets nest on ELTs but we all know more now. Thanks to all that replied.
Lee

info from CAP

There was a discussion on 406mhz ELT's and someone from cap made this comment;

"121.5 will still be picked up by SAR DF equipment however as of 2/1/09, the Air Force Rescue Coordination Center will not pick up any hits from their satellite system and therefore will not dispatch CAP resources to find the ELT.:

Xavier - the information you've shared is common to both the US and Canada. While our old 121.5MHz ELT's will still activate in a crash, the signal they transmit will not cause Search and Rescue forces to be scrambled. If we're lucky an over-flying airliner will hear our ELT warbling away and will alert ATC who will in turn alert the Rescue Coordination Unit. Then again, we might not be so lucky.

The advantage of the 406MHz ELT is that upon activation its signal will be picked up by satellite and immediately relayed to the Rescue Coordination Centre (and as a result of it being a 406MHz signal the size of the search area will also be much smaller). These satellites are currently in service so anbody who opts to install a 406MHz ELT can benefit immediately. Umm, maybe I should say "could benefit immediately" since it is my sincere hope that none of us will ever need to rely on an ELT! ;-)

With respect to an earlier question, Norman hit the factual nail on the head. As of this moment, a US-registered aircraft, homebuilt or otherwise, may fly into Canada with an operational TSO C91 or TSO C91a ELT. Whether this continues to be the case in the future remains to be determined. So far some very vocal feedback from the Canadian general aviation community seems to have caused Transport Canada to take a hard look at their draconian legislative proposals. Or maybe they're just hoping our grassroots backlash will lose steam over time...

Canadian exemption - also Mexico

Canadian_JOY said:

.....
With respect to an earlier question, Norman hit the factual nail on the head. As of this moment, a US-registered aircraft, homebuilt or otherwise, may fly into Canada with an operational TSO C91 or TSO C91a ELT. Whether this continues to be the case in the future remains to be determined. So far some very vocal feedback from the Canadian general aviation community seems to have caused Transport Canada to take a hard look at their draconian legislative proposals. Or maybe they're just hoping our grassroots backlash will lose steam over time...

Click to expand...

This question came up at the 2008 Grumman Convention in Burlington, IA, since they have scheduled the 2009 convention for Red Deer, Alberta.

The word is that Canada will issue a two year "stay" on the 406 ELT order for visiting US planes, but since the original order is not yet effective, the government has no way of issuing an exemption to a rule that does yet exist - sounds like a typical government statement....

With assurances from Canadian Transport and the local governor (or what ever they are called in Canada......) the Grumman group (the American Yankee Association) retained the scheduled location in Canada.

Expect a 2 year exemption for visiting US planes - don't know about the natives though....

BTW... this is all coming about because of an ICAO ruling using the old "harmonizing" excuse for conformity. Apparently the US has decided to be an exception this time.

This came from the Baja Bush pilots.... Mexico is also harmonizing....

406MHZ ELTs Now Required For Mexico

The following is as published by Baja Bush Pilots http://www.bajabushpilots.com/:

This morning (July 10, 2008) we received an e-mail form Mauro R. Gomez Peralta Damiron, Sub-Director of the DGAC who indicates the following:

That in order for an aircraft to fly in Mexican Airspace, that after July 1, 2008, the aircraft must have a 406MHz ELT installed in the aircraft.

However, for aircraft that do not have a 406MHz ELT, Mexico is making an allowance for continued use of existing 121.5 ELTs to July 1, 2009 or, when the battery on the existing 121.5 ELT is due to be replaced, which ever comes first.

This "Card of Policy" is going through the process of becoming an integral part of the PIA in which the obligatory date declared is July 1, 2008, but stating the allowance as indicated above.

The PIA is Mexico's Publicacion de Informacion Aeronautica or, the official manual containing the rules and regulations for flying in Mexico as well as contains a listing of all International Airports. It is much like the Jeppesen except it is an official government publication.

In a follow-up conversation with Captain Gomez, we confirmed the following:

That this allowance is for all aircraft, private (not for hire) and commercial (for hire). That this Card of Policy is still being generated and will be circulated to all airport Commanders within the next several days.