Tell me what you think

I didn't like the standard ELT mount that vans sells. It sits way too close to the rudder cables and isn't that sturdy once installed. I build my own and added a "dog house" on top in order to mount the antenna.

The Ameri-King install instructions for TSO-C91a state that the antenna needs to be within 20 deg of vertical so I didn't want to put it under the tail fairing.

The mount I built keeps it close to the ELT and is a simple solution.

I know others have talked about the ability to get to the ELT after an accident. I'm not really concerned about that.

Was wondering if you guys had any thoughts???

Thanks Marc

it appears functional enough.

If it were located in the baggage area, it would be more accessible to change/check the batteries.

Marc,

As long as the rescuers are sitting inside the fuselage with you, they should have no problem hearing that ELT.

The antenna needs to be OUTSIDE the all-metal fuselage to be able to radiate to the outside world with any kind of strength at all. Nice looking mount, but if you're trying to meet the manufacturer's recomendation, that won't work.

Like Paul says, the antenna must be outside the metal fuselage or at least in the cockpit area where the antenna can "see" through the canopy. Even being in the cockpit area, you will still have some directional "shading" of the signal.

Antenna absoulutely has to be outside of the airplane.

On a side note

1) I'd be concerned with the rigidity of the ELT.

In a high G environment, like a crash, I'd worry about the ELT slipping inside the harness, or shearing the dog ears on the sides, or absolutely jumping over the dog ears.

2) I'd worry about the buckle coming unlatched in the course of the accident.

3) I'd worry about the strength of the strap the hold the ELT against the bracket.

That 1 strap and buckle is all it has to count on. Sure hope it doesn't fail or become unbuckled in the course of the accident!!

If it slips at all, it's very unlikely that the ELT will ever be triggered.

The more ridged you can make the bracket and the ELT mounting to it, the better. You want to make sure it's mounted solid enough to be triggered at impact.

Phil

Ok

Ironflight.
I've already ordered my baggage compartment sized SAR assets. Hasn't everyone??

Phil.
The mounting hardware that you see in the picture (strap, buckle, and first bracket) is actually supplied by Ameri-King Corporation. The second underlying bracket was built by me and is a lot sturdier than the one supplied by Van's. I agree that the antenna has to be outside in order for it to achieve its rated transmission range.

I've seen a lot of installations where the antenna is placed in the tail horizontally below the fairing. Granted this is better than my crazy idea of hiding it behind the baggage compartment, but how much better??? It doesn't meet the TSO-C91a requirement. Nor does putting it in the baggage compartment where it has partial view of the sky through the canopy.

What I'm really concerned about and why I bring this up. I don't want to come up for my DAR inspection and have to move the antenna.

Thanks for the feedback

Is it worth worrying about

Mel was wondering if you had any suggestions or ideas on this one? Anybody have any problems when it came to the DAR inspection about having the antenna in the aft fearing?

Thanks for all the help.

Marc

re: solo flying

If memory serves me correctly, you don't have to have an elt if you're flying solo, like flying your time off. If this is correct, don't even install it till you're ready of haul pax's, then put it where you want it and how you want it. Won't be a DAR concern then. Although, I'd want it as close to right as possible/practical.

Marshall Alexander
RV10 N781DM

RV10Man said:

If memory serves me correctly, you don't have to have an elt if you're flying solo, like flying your time off. If this is correct, don't even install it till you're ready of haul pax's, then put it where you want it and how you want it. Won't be a DAR concern then. Although, I'd want it as close to right as possible/practical.

Marshall Alexander
RV10 N781DM

Click to expand...

I can't remember the specifics (it has been a few years since I dealt with certification of an E-AB) but I am pretty sure part of your certification paperwork requires a statement of how many seats the aircraft has. If you are not equiped to carry more than one person, I would think a DAR would not let you fill paperwork out as being a multi seat airplane.

Mel?

marchudson said:

I've seen a lot of installations where the antenna is placed in the tail horizontally below the fairing. Granted this is better than my crazy idea of hiding it behind the baggage compartment, but how much better???

Click to expand...

Under the fairing is much better (though still not great). If you mount the antenna inside that aft fuse, it is in an almost perfect faraday cage. I'd be surprised if you could receive its signal from one end of the runway to the other.

In theory I'm an EE, but all my RF knowledge is too rusty to give you a more specific answer.

There are two entirely different questions being discussed here: 1. how should the ELT unit and antenna be mounted to satisfy the legal requirements, and 2. how should the ELT unit and antenna be mounted so that they will actually have the best chance to do their job if called upon. When discussing this topic, we should be explicit about which criteria we're trying to satisfy. I would say hopefully both, but in fact many ELT installations I've seen in RV's may meet #1 but not #2. Even the common practice of mounting the ELT antenna inside the cockpit or inside the empennage fairing are examples of this. Major shadowing, wrong antenna orientation, inadequate ground plane, etc.

I haven't installed my ELT yet, but just last week I researched the topic and did a brief write-up on what I learned:
http://www.kalinskyconsulting.com/rvproj/elt.htm

P.S. to answer the original question: mounting the antenna inside the fuselage like that is a definite NO GO, as others have already explained.

marchudson said:

...Anybody have any problems when it came to the DAR inspection about having the antenna in the aft fearing?

Click to expand...

I mounted the antenna in the aft fairing. I had my airplane inspected by the local FSDO. The inspector (who had a background in avionics) said that he thought the antenna should be mounted vertically. I didn't have the ELT manual handy at the time, so he asked me to check on it (but not to report back to him). He probably still would have given me the airworthiness cert even if I had the manual with me.

I checked, and yes, the manual stated that the antenna is designed to be mounted vertically. I didn't change it and don't intend to. I agree that this location is probably not very effective, but I'm also not a real believer in ELT's either. Just my personal view.

ericwolf said:

I mounted the antenna in the aft fairing. I had my airplane inspected by the local FSDO. The inspector (who had a background in avionics) said that he thought the antenna should be mounted vertically. I didn't have the ELT manual handy at the time, so he asked me to check on it (but not to report back to him). He probably still would have given me the airworthiness cert even if I had the manual with me.

I checked, and yes, the manual stated that the antenna is designed to be mounted vertically. I didn't change it and don't intend to. I agree that this location is probably not very effective, but I'm also not a real believer in ELT's either. Just my personal view.

Click to expand...

Mine is horizontal in the aft fairing too, and will stay that way. Over the years, this issue has been brought up again and again. And much comes down to what position the tail/fuse will be in, should the ELT need to activate. There is no real answer for that, is there?.....

Afterall, if the fuse is upside down, buried in dirt, then what good is a top mounted antenna? And so on & so on...

L.Adamson --- SPOT satellite tracker ... on board

Are you sure???

Phil said:

Antenna absoulutely has to be outside of the airplane.
<<SNIP>>

Phil

Click to expand...

Our ELT antenna is mounted under the fuselage/vertical stab fairing. And it WORKS!!!

How do I know???? ...

Well a few years ago, after arriving at SnF, someone blew a LOT of dust into the plane. I got inside to wipe the dust from the panel etc. and accidentally hit the little "ON" button. Since it was BRIGHT sunlight, I did not notice the red light was on and proceeded to the vendor booths. Well after about one building of looking around, I had a call from the search and rescue people. They had been informed that and ELT was activated at Lakeland airport and they had the task of finding it amoung the thousands (??) of planes there!!

Found it and had me meet them at the plane (NOW!). They were surprised that they did not see and antenna and wondered where it was. There was no issue with them about signal strength.

On another note, who is to say what the orientation of a crashed plane is going to be? And thus the best orientation for the antenna for after crash location.?

jclark said:

Our ELT antenna is mounted under the fuselage/vertical stab fairing. And it WORKS!!!

How do I know???? ...

Well a few years ago...

Click to expand...

There are no absolutes to this (absolutely will work vs. absolutely won't work), but there are significant relative differences in effectiveness between different mounting configurations. Mounting the antenna in the shadow of metal structures, without a good ground plane, and/or with incorrect polarization, will adversely affect the signal strength and radiation pattern. One data point showing that a signal transmitted with a sub-optimal antenna configuration was still received in one particular situation doesn't negate that fact.

jclark said:

On another note, who is to say what the orientation of a crashed plane is going to be? And thus the best orientation for the antenna for after crash location.?

Click to expand...

Indeed, you can't predict with 100% certainty in what orientation the airframe is going to end up following a crash. However, that doesn't mean that all possible orientations are equally probable. Presumably, the most probable scenario of a survivable crash would be that the fuselage still ends up more-or-less upright. Hence the antenna mounted vertically on top. The next most probable outcome would likely be that the fuselage ends up more-or-less inverted. In this scenario a bottom-mounted vertical antenna would have been ideal, but even a top-mounted vertical antenna would have still been better than an antenna buried somewhere inside the airframe, assuming that the vertical stabilizer didn't entirely collapse and is holding up the tail. A top-mounted vertical antenna is not the best answer for all possible scenarios, but rather it is the best guess if you will, the best statistical compromise, the best answer over a weighted average of all possible scenarios.

If anything, the uncertainty about fuselage orientation following a crash is another good argument in favor of making the ELT easily accessible/removable and having a portable antenna stowed away with it. Either that, or carrying a second portable PLB, Spot, etc. on your person.

There are no absolutes to this stuff, but that doesn't mean we can't make decisions that significantly influence the probabilities in our favor. One can choose not to, and there are trade-offs to be made (e.g. ELT effectiveness vs. lower aerodynamic drag...). But let's not fool ourselves into believing that these decisions are arbitrary and inconsequential.

Aft fearing it is

Eric I'm not a big believer in ELTs either. I'm going to mount it in the tail under the aft fearing. Thanks everybody for all the valuable input.

Marc

Agreed Roe...

I've spent several years plotting RF radiaition patterns and designing antennas over the years. There's no doubt metal structure seveverly affects radition patterns and attributes to signal attenuation.

It's one thing to be found on an airport where folks are close by and can report an ELT. It's a different thing when you're stuck on a mountain side in the Rockies.

Like you said, people can mount them where ever they like. But for me, mine will be outside.

Or maybe, since I'm building a -10, I'll build a simple design that can be embedded within the fiberglass cabin top. That's the next best thing.

I guess this is a good thing for the 400mhz ELT's too. Antennas that are significantly smaller. Can't beat that!

Needless to say though.. I'll continue to carry my Find-Me-Spot. I like the idea of leaving bread crumbs for someone to follow later.


Phil

Phil said:

I guess this is a good thing for the 400mhz ELT's too. Antennas that are significantly smaller. Can't beat that!

Click to expand...

It's true that a 406 MHz antenna will be about 30% of the length of a 121.5 MHz antenna. But since a 406 MHz ELT still has to transmit on 121.5 Mhz too, the thing you put on top of the airplane isn't any shorter. The one I've got my eye on is the ACK E-04... I assume from the shape that they are using two antenna elements in the same package:



mcb

Vertical mount of Antenna

ericwolf said:

... the manual stated that the antenna is designed to be mounted vertically.

Click to expand...

Make sure you crash with the nose pointed down.

marchudson said:

Eric I'm not a big believer in ELTs either. I'm going to mount it in the tail under the aft fearing. Thanks everybody for all the valuable input.

Marc

Click to expand...

It's statements like this that reveal the most common problem with ELT's... By installing the ELT antenna poorly you're making poor ELT performance a fait accompli. Talk about a self-fulfilling prophesy! To make a logical comparison, applying this same style of thinking is kinda like saying that in a dual magneto system one often finds troubles with one magneto while the other runs just fine, so we're only going to install one magneto to avoid having troubles with a dual system. It's hard to believe that folks who can build a machine as complex as an airplane would work so hard to defy logic and common sense. And put themselves and their loved ones at risk in doing so!

There are a few folks in this forum who know their stuff when it comes to avionics. There are even fewer folks in the forum who know their stuff when it comes to avionics and the specifics of electromagnetics and antenna design for avionics equipment. It truly is a shame when their few sage voices are drowned out by the many voices crying out that it's preferable to have a pretty airplane over having a functional Search and Rescue alerting system.

Guys (and gals) - let's get focused here. You wouldn't intend on building an RV10 with the intent of doing hard IFR and then go burying its nav antennas inside the tailcone where their performance would, at best, be marginal. If anybody suggested to you to install that antenna in any way that would compromise your nav performance or your ability to shoot an approach to minimums, you'd scream "NO WAY" so loud you'd be heard on Mars. So when it comes to an ELT antenna, why not do it right, just as you would with that all-important nav antenna?

Mount your ELT antenna on the exterior of your metal aircraft, as close to vertical as possible and as far away as possible from interfering metal structure (read vertical stab on an RV).

It really is that simple. Period.

Sorry if my comments may have offended some readers but as a guy who's seen lives saved and lost based on ELT performance I simply cannot sit on my hands while folks are deciding to install their ELT antennas in a manner that clearly will result in compromised operation. Its even more difficult to read posts where esthetics are clearly taking precedence over operational performance considerations. Let's hope none of us ever have to rely on the distress signals of our ELT or other SAR alerting device. For those of us unfortunate enough to have to use them, let's hope they were installed so as to ensure the fastest possible rescue time.

Thank You Mark!

Words to live by.

I am also a believer that the ELT serves little purpose. Their activation rate is not great. What about the ELT for the rich guy in California? Did it work?

I have a 406 MHz PLB and use flight following whenever possible.

If you really want to be rescued or recovered, consider a Spot or APRS. A PLB should also help but offers different capabilities than Spot or APRS.

Of course all of this is opinion and may offend experts.

I did not read the words to LIVE by but let's do less of the things for which an ELT may have some value. Don't run out of gas, fly in bad weather, do aerobatics low, or other stupid things. Read the Nall report and don't do those things.

CanadianJoy's treatise on ELTs makes eminent sense. Since we have to have it, let's install it so it works and works WELL.

Canadian_JOY said:

It's statements like this that reveal the most common problem with ELT's... By installing the ELT antenna poorly you're making poor ELT performance a fait accompli. Talk about a self-fulfilling prophesy! To make a logical comparison, applying this same style of thinking is kinda like saying that in a dual magneto system one often finds troubles with one magneto while the other runs just fine, so we're only going to install one magneto to avoid having troubles with a dual system. It's hard to believe that folks who can build a machine as complex as an airplane would work so hard to defy logic and common sense. And put themselves and their loved ones at risk in doing so!

There are a few folks in this forum who know their stuff when it comes to avionics. There are even fewer folks in the forum who know their stuff when it comes to avionics and the specifics of electromagnetics and antenna design for avionics equipment. It truly is a shame when their few sage voices are drowned out by the many voices crying out that it's preferable to have a pretty airplane over having a functional Search and Rescue alerting system.

Guys (and gals) - let's get focused here. You wouldn't intend on building an RV10 with the intent of doing hard IFR and then go burying its nav antennas inside the tailcone where their performance would, at best, be marginal. If anybody suggested to you to install that antenna in any way that would compromise your nav performance or your ability to shoot an approach to minimums, you'd scream "NO WAY" so loud you'd be heard on Mars. So when it comes to an ELT antenna, why not do it right, just as you would with that all-important nav antenna?

Mount your ELT antenna on the exterior of your metal aircraft, as close to vertical as possible and as far away as possible from interfering metal structure (read vertical stab on an RV).

It really is that simple. Period.

Sorry if my comments may have offended some readers but as a guy who's seen lives saved and lost based on ELT performance I simply cannot sit on my hands while folks are deciding to install their ELT antennas in a manner that clearly will result in compromised operation. Its even more difficult to read posts where esthetics are clearly taking precedence over operational performance considerations. Let's hope none of us ever have to rely on the distress signals of our ELT or other SAR alerting device. For those of us unfortunate enough to have to use them, let's hope they were installed so as to ensure the fastest possible rescue time.

Click to expand...

Just have to disagree; as it's a tough call to say what's a compromised installation; as in top of plane versus the fiberglass tail fairing. I'd never compare the ELT antenna placement to running dual magneto's versus a single, or nav antenna's that have little chance of working. As this same question has been hashed over & over for a number of years............... we don't know how a crash is going to end up. The vertical fuse mounted antenna could easily be ripped from the airplane. The cable could be severed etc, etc, etc.

If you really want to have a better chance of being saved, then carry a SPOT or similar in your "pretty plane". I run mine on every cross country, and it's worked flawless for the year I've owned it. The 911 button will give an exact GPS coordinate while alerting authorities & "loved ones". Or rescuers will at least have a good trail to search if the button isn't activated. With technology such as SPOT, I see ELT's as having less importance than in the past. And since I decide flight directions on a whim much of the time; SPOT can make up for not wanting to fly a specific route, as is required when filing a flight plan. And in mountainous areas, SPOT can also make the difference when flight following just doesn't work, due to lack of radar coverage at lower altitudes. SPOT --- a good investment of $150 per year!

L.Adamson --- RV6A

Canadian_JOY said:

...Mount your ELT antenna on the exterior of your metal aircraft, as close to vertical as possible and as far away as possible from interfering metal structure (read vertical stab on an RV).

It really is that simple. Period.

Sorry if my comments may have offended some readers but as a guy who's seen lives saved and lost based on ELT performance I simply cannot sit on my hands while folks are deciding to install their ELT antennas in a manner that clearly will result in compromised operation...

Click to expand...

Good points. Location is very important. I think the ELT antenna on my RV-6 is pretty much in the optimum position for performance. If there is a better place, I couldn't think of it.


But there is a problem. Location on a tip-up RV-6 is easy but what about an RV-8? There doesn't seem to be a good location. The slider, which goes pretty much back to the vertical stabilizer, precludes top of the fuselage mounting. You are left with bottom of the fuselage, cockpit, wing-tip or under the tail fairing. None of those seem good, but those are the choices.

n5lp said:

But there is a problem. Location on a tip-up RV-6 is easy but what about an RV-8? There doesn't seem to be a good location. The slider, which goes pretty much back to the vertical stabilizer, precludes top of the fuselage mounting. You are left with bottom of the fuselage, cockpit, wing-tip or under the tail fairing. None of those seem good, but those are the choices.

Click to expand...

Yup - the RV-8 presents NO surface that satisfies the ELT manufacturer's criteria in their entirety, so we are forced to compromise. I agree with the philosophy that you should do as well as you can (even though the success rate of ELT finds is poor), just on general principle.

(And carry a GPS-enabled PLB )

Paul

L.Adamson said:

Just have to disagree; as it's a tough call to say what's a compromised installation; as in top of plane versus the fiberglass tail fairing. L.Adamson --- RV6A

Click to expand...

Ummmm... Don't want to sound too argumentative here, but it's not at all a tough call. The fiberglass tail fairing installation IS a compromised installation, and a pretty severly compromised one at that. The ELT antenna radiation pattern that provides best probability of rescue is an omni-directional pattern, ie radiating equally in all directions. The tail fairing installation will produce a radiation pattern that is not omni-directional - far from it. I have not done a field measurement on this installation in particular but have done surveys on similar installations and the radiation patterns were pretty ugly, definitely nothing like omni-directional, with a deep notch where almost no signal was radiated directly to the rear of the aircraft. With this being the case, doesn't matter whether your airplane is right side up or upside down, your ELT may not be detected as a result of this disfigured radiation pattern.

One other comment on aircraft flip-overs... Let's face it, this is a big concern to all of us, irrespective of which aircraft we fly. If you were to string a wire between the top of the vertical stab and the back of the baggage compartment, any "stick" type antenna that's installed beneath that wire is pretty well protected if the aircraft flips on its back. Most airplanes, and particularly the RV's, are built strongly enough that the empennage survives reasonably intact, with the vertical stab acting as a brace to stop the fuselage from settling to the ground and crushing the antennas mounted on the spine of the airplane.

There have been lots of comments made about SPOT and PLBs, and a certain "rich guy from California". But let's be honest. Few of us know that we're going to crash. Heck, if we knew in advance that we were going to crash, well, we'd take steps to avoid crashing, wouldn't we? The reality is that most of us get caught up in situations which deteriorate so rapidly that hitting that 911 button on SPOT or holding down the switch on the PLB for 3 seconds just isnt' going to happen. In the case of the rich guy from California, do you think Steve, an extremely accomplished pilot, had time to do ANYTHING before he smacked into that granite overcast? An overwhelming body of evidence allows us to conclude that manually activated beacons just don't work because the crash has happened before we could even reach for the beacon. That's why automatically-activated devices called ELT's were developed in the first place.

For those who don't have faith in ELTs I would urge you to seriously consider the origins of that lack of faith. Keep in mind that our statistical information lumps all ELTs together, including those very earliest ELTs which by today's standards are seen as being pretty crude and highly unreliable. If we were able to separate the data by ELT TSO type then we would see that each generation, from TSO C91 to C91a to C126 (the current 406MHz standard) offers substantially improved performance over its predecessor. If you don't have faith in ELTs its because you're looking at history, not at current state-of-the art. Applying the same logic to airplane engines, if we looked only at the statistics from the early years of airplane engines, the reliability would be so low that very few of us would risk going flying. (Fortunately engine reliabilty stats have been updated and are available to us on a "per type" basis, completely unlike our ELT reliability stats...) Take a hard look at the new 406MHz ELTs - they really are a totally different animal than their predecessors. Canadian experience to date with these devices is extremely positive.

The RV8 presents a real challenge for antenna installation. My hangar-mate's -8A has a reasonably good compromise in its ELT antenna installation. It's mounted slightly off-center and points out at an angle so it's not totally vertical. But it's got a pretty clear view of the sky, is as far away from metal structure as is possible, and makes a nice place to hang your jacket (only kidding, really!). As Ironflight commented, it's best to understand what makes an optimal installation and then strive to achieve that optimal installation within the other limitations imposed by the airframe.

OK, time for me to get off my soapbox. I'm a firm believer in ELTs. Not because as a licensed AME I sometimes install them for friends. But because a good friend of mine owed his life to an unrecognizeable lump of melted plastic that at one time had been a Narco ELT-10. The post-crash fire consumed the aircraft but the ELT kept bleating out its plaintive call. The day I saw the remains of that ELT is the day I became an ELT advocate. There, but for the grace of God, go I...

On my -8 the ELT antenna is under the empennage fairing. I did not build the airplane so I don't know if it was installed before or after the DAR inspection. In any event, I'm not too worried about it being in a 'non-recommended' orientation. As has been pointed out the functionality of an ELT is iffy in the event of a crash. What I have done is buy a Fast Find PLB (OSH for $275). If I know I'm gonna crash I'll try to activate it before I connect with terra firma. If there's no time, and I survive, I'll activate it later. In a catastrophic accident event the ELT very likely will not work because wires, connectors, etc. will probably be broken. From my viewpoint the installation of an ELT is a check the box regulatory requirement. That's the reason I have a PLB. If I'm still alive it has a good chance of working and assisting with my rescue.

It appears that there will be two groups on ELT matters. It was Mr Fossett. Took me a while to remember his name (age issues).

I will take the viewpoint, similar to the post above mine, that a Fossett type accident is largely preventable...so don't do it.

The recent Tulsa, OK are accident that killed five may be another preventable accident once facts are known.

I have a 406 MHz GPS enabled PLB. if I am high enough and the engine quits, I 'should" have time to activate it. That is where it comes in handy.

A device like Spot is even better since it leaves position reports even if the pilot does not activate it. For RVs, the reporting time could perhaps be shorter, but even as is, it would be very helpful.

As far as activation reliability, please point us to a source.

SPOT lays a trail > > > > > > (I'm here)

Canadian_JOY said:

There have been lots of comments made about SPOT and PLBs, and a certain "rich guy from California". But let's be honest. Few of us know that we're going to crash. Heck, if we knew in advance that we were going to crash, well, we'd take steps to avoid crashing, wouldn't we? The reality is that most of us get caught up in situations which deteriorate so rapidly that hitting that 911 button on SPOT or holding down the switch on the PLB for 3 seconds just isnt' going to happen. In the case of the rich guy from California, do you think Steve, an extremely accomplished pilot, had time to do ANYTHING before he smacked into that granite overcast? An overwhelming body of evidence allows us to conclude that manually activated beacons just don't work because the crash has happened before we could even reach for the beacon. That's why automatically-activated devices called ELT's were developed in the first place.

Click to expand...

Without again, reviewing the Steve Fosset case, I can assume that the aircraft's ELT didn't activate or was destroyed. Had he been using a SPOT, at least his general direction of travel would have been known from a time range of less than a second to ten minutes. This would at least kept searchers in the correct area, even if they missed the crash site on the first round. That's the SPOT advantage...................it's "automatically" laying a trail to follow every ten minutes, and does a good job of it. I can assume that even the newest ELTs won't be sending any type of location information during the coarse of the flight; but only upon activation. You can only hope the ELT sends the GPS coordinates before it's crippled or destroyed in the worst case scenario.

L.Adamson

Nail on head

flickroll said:

From my viewpoint the installation of an ELT is a check the box regulatory requirement. That's the reason I have a PLB. If I'm still alive it has a good chance of working and assisting with my rescue.

Click to expand...

Didn't mean to open the ELT can of worms but I think Jim hit it right on the head with the comment about the regulatory requirement. After flying 20 years off the boat in the Navy carrying every conceivable piece of survival gear strapped to your vest, you started to get a good feel for what would work and what wouldn't. Also, you got a quick picture of what was important from the guys that did go down and what they used. Don't get me wrong, I'm sure there are stories of ELTs saving lives, but for some reason I see a SPOT or PLB in my future.

On a more humorous note, if I do crash my aircraft and am still alive, I'm not sure I want to be found.

Here's to concentrating on not having to use this stuff.

Marc

Just to qualify some of my statements, although ELT's have no doubt saved some peoples lives, I believe more in the more effective technologies such as Spot. Our local CAP gave a presentation at our EAA chapter recently and they said that well over 95% of ELT's going off are false alarms whereas they only activate something like 20-30% of the time when they are supposed to. Of course, some units will be better than others.

I completely respect the opinions of those who believe in ELT's and place the antennas outside of the aircraft. As Paul mentioned, there really isn't a good place to put the antenna on an RV-8. To be fair, we don't know if rescuers wouldn't be able to find me simply because the antenna is located under the emp fairing. My feeling is that IF I crash my airplane and IF I can't activate my Spot or use my cell phone and IF I'm still alive and IF I'm unconscious and IF the ELT actually activates and IF it isn't damaged and IF the antenna location is too compromised for anyone to pick up the signal, then I guess that I'll be wishing that I had found a better place for the antenna, but I'll take my chances. This is only my personal feeling, do whatever you want on your own aircraft.

To put things in perspective, there are likely very few of us who fly at night with only one flashlight. Nobody's comfy with putting all their eggs in one basket. Same goes for SAR alerting technologies. Why have just an ELT when you can also carry a PLB or SPOT or both for little extra cash and payload penalty? Those PLB's and SPOTs are NOT BAD things at all. Anything you can do to stack the deck in your favor is a GOOD thing! But when you smuck into terra firma it's nice to know the backup plan to your backup plan will automatically come into play, irrespective of your state of consciousness or other health.

With respect to Steve Fossett's crash, it was not survivable. He flew into a mountain and the post-crash fire consumed everything. Even if the ELT had a chance to activate it likely didn't operate for very long. But the relief his widow would have felt had that trail of SPOT breadcrumbs been available would have been well worth the $150 subscription fee.

There was an earlier comment about false alerts with ELTs. The honest truth is that lots of ELTs are activated in non-emergency situations. That's a real problem because we end up scrambling SAR resources to search for an ELT in the trunk of a car. Not good! The problem with our TSO C91 and C91a 121.5MHz ELTs is that they're completely anonymous so when one is heard transmitting the SAR agencies have no idea who's it is, and only a rough idea of where it is. The beauty of the 406 MHz ELTs is that they are coded to match our aircraft (N number in the US, ICAO code in Canada). This means they're not at all anonymous. When you register your 406 beacon you provide emergency contact info. When a beacon is heard transmitting the first thing SAR does is a communications search - VHF, flight service, your home phone, cell phone, etc. The big success in Canada has been in NOT scrambling SAR resources for false alerts. I was able to witness one false alert from a 406MHz ELT where it took a total of 8 minutes for SAR to conduct a communications search, get in contact with the owner and determine the beacon they heard was being installed and had just been left on too long during testing and had transmitted a valid encoded signal. By anybody's books that's waaay better than scrambling a C-130 into marginal weather conditions at night to search for a 121.5 MHz ELT.

While the US regulatory requirements don't mandate installation of 406MHz ELTs there's still a vast array of good reasons why, as new airplane builders, we should consider installing this new technology. I've enumerated some of those reasons here, and I've got a long list of other good reasons to make the switch to 406. It just makes sense to have a backup plan that gives you the best chances of survival.

Oh, by the way, at OSH we were able to see a very spiffy new 406MHz PLB on sale for under $300. It's very small, light and supposedly quite durable. This is a big step forward in PLB technology and very worthy of carrying as a backup to our ELTs. And PLB's don't require any on-going subscription like SPOT so some folks may find them a more economical auxiliary SAR alerting device.

Just remember, if you buy a 406MHz ELT or PLB, make sure you register it and keep the registration information current since that info is what will be used to initiate SAR activities.