My 406Mhz ELT went off, what happened was a bit unnerving

The 406 units are head and shoulders better than the old.

Homing in on a 121.5 unidentified signal versus getting a satellite signal tagged with the sender's ID and hopefully with GPS coordinates, will ease the load on responders by an order of magnitude, though I'll admit I've never done that work.

I have indirectly observed a search for glider crashed up in some trees where the pilot was uninjured and on the radio, his signal was homed in on, aircraft were overhead and I had to leave before they could locate him. I've crashed a glider within 100 feet of a shopping mall parking lot. No one ever saw it despite sitting for 6+ hours. Fortunately I was uninjured and could walk to a phone (how long ago was that?) Finding crashed aircraft can be very tough. Of course it won't ever happen to me again but I want the deck stacked in my favor.

My Ack unit get's it's GPS signal externally. I will be doing my 3rd annual test and check next month.

I'm highly motivated to make sure it doesn't trigger accidently - you have to replace the lithium battery and that's pretty pricey. Plus it just shouldn't happen though I can't figure out what is different about the triggering mechanism between the old and new units. I hope some new technology has been applied there.

Turning these units off when parked is inconsistent with how they are to be installed in many or most aircraft. That just defeats to many of the benefits.

Teething pains in new technology is not unheard of. This is a big leap from what we had, it will save SAR $$ and effort, it will improve survivability. It's the law.

That's what I think anyway... YMMV obviously.
 
All of this would be completely avoidable if ELTs(and associated SAR) were opt-out. Nanny state by design, and poor design at that.
 
docmirror said:
All of this would be completely avoidable if ELTs(and associated SAR) were opt-out. Nanny state by design, and poor design at that.
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Any opt-out would include the statement that no taxpayer money would be spent in looking for you if you disappeared. Search and rescue costs a fortune.


Dan
 
Dan Thomas said:
Any opt-out would include the statement that no taxpayer money would be spent in looking for you if you disappeared. Search and rescue costs a fortune.


Dan
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Can I quote you on that? Oh look, I already said that in the post you quoted.

(and associated SAR) were opt-out

Citizens are not allowed to be responsible for themselves anymore, even if they wanted to be.
 
Clark1961 said:
internal gps - the selection of which is best isn't clearcut since there are many possible failure modes for any gps/elt system

my thought when making the purchase decision was that a gps built into the ELT was the simplest and therefore best system - not so sure now since I did not buy the "walkout" antenna
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Makg suggested that everyone should disable their ELT when parking their airplane. I was pointing out that in many aircraft including mine, that's rather difficult to accomplish.
 
wsuffa said:
But that's not how it works in real life. The expectation (for a variety of reasons) is that you will go disable it ASAP, even if it's the middle of the night. What it does do is minimize/eliminate the SAR response.
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The SAR response has already happened - they called you. They're not gonna hang up and then go oh, look, it's still there, and call you again. It's already been resolved and isn't going to bother anyone.
 
Silvaire said:
Well for one thing 406 MHz ELT's are registered and identified by their signal so the first thing anyone is going to do is call you. Once it has been determined that there is no emergency there's no point going out there in the middle of the night to turn it off because you're already going to have to replace the battery anyway so may as well wait 'till morning.
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If the person registers them. We've chased unregistered ones multiple times. Best one was the guy who's wife bought it for him thinking it was an avalanche beacon. He dutifully took it out of the box, put batteries in the PLB, and hooked it to himself and activated it every time he went cross country skiing in the backcountry alone.
 
Dan Thomas said:
Any opt-out would include the statement that no taxpayer money would be spent in looking for you if you disappeared. Search and rescue costs a fortune.
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Colorado has an insurance program for this. Buy a fishing license or hunting license or go pick up a backcountry insurance slip at places that sell them for just a few bucks, and you won't get a bill if you have to be rescued. Don't and the jurisdictions that came looking for you may send you a bill. The bills were unpopular politically at first but politicians are distanced enough from it that it's not costing them reelection so they're more commonly sent than not sent now.

(Heck even cities are billing people who live in other cities for city ambulance and fire services now. It's a money-maker and no one is saying boo.)
 
MAKG1 said:
You want me to get up in the middle of the night to look for your sorry butt when the airplane is parked and empty?

Turn the damn thing off and think about someone else. ELT searches can be rough on dozens of volunteers just so you can get your notification. That is not an emergency, and it's a wild misappropriation to use an emergency channel for that. You'll hear about it soon enough from more legitimate channels.

It gets REAL rough when your POS goes off at the same time as someone else's 121.5, as you can only DF the stronger signal.
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Wow, my very first post and I'm insulted by someone who completely misinterprets my overall message. What in the world are you talking about MAKG? Do you and all your buddies turn off your ELT's every time you leave your plane? If a tornado launched your plane into a barn, you wouldn't want a phone call from the Air Force. Bull.

In case you did not read my post carefully, you will see that I have been troubleshooting this since it started and I happen to be an advanced electronics specialist. Each false alarm was from different conditions (land, level @ 10,000 feet and takeoff) and I have worked directly with ACK support while probing test points and voltages with a meter under my console.

As to inconveniencing you, the Civil Air Patrol (I am a member, BTW) and the Air Force, I have complied with their request while I await a replacement ELT from ACK because I believe mine is defective. There was no intention in my post of causing anyone undue harm or insinuating that I'll leave my ELT armed, screw the Air Force! (I'm also a disabled Navy Vet so I would not want to inconvenience any member of any armed service).

Final word: My reflection was stating the absurdity of the fact that I had to disarm the ELT manually due to a defect, whereas my previous 121.5 was rock solid and never failed. The big picture was to offer another story to validate the fact that more than one person has experienced this problem. The Air Force is currently experiencing a 90% false alarm rate and I'm trying to contribute to the SOLUTION by sharing information. Take your insults to another board please. I may be new but I have also read the poicy against personal attacks.

I've said my peace. All I ask is that you read posts more carefully before reacting in such a non-sensical way.
 
Welcome to POA where posting a comment is like poking a grumpy old dog with a stick :D
 
We went to OSH looking for a 406 MHZ ELT. We learned that we want one with a built-in GPS, and that they're too expensive.

So, we bought a 406 MHZ personal locator beacon instead. We'll have to be conscious after the crash to trigger it, but it floats and can be taken camping, hiking, etc. $269.

We'll put one in the plane next OSH.
 
Jay Honeck said:
We went to OSH looking for a 406 MHZ ELT. We learned that we want one with a built-in GPS, and that they're too expensive.
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FWIW, reports are that the SARSAT position reports for non-GPS-equipped ELTS are good enough to just send the SAR responder to the reported location, followed by little or no searching.

The advantage of the GPS-equipped ones is that the geostationary bird gets the location immediately. If not GPS-equipped, it takes a couple of passes of LEO birds to work out the location. IIRC this can take an hour or two.
 
Jay Honeck said:
So, we bought a 406 MHZ personal locator beacon instead.
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Be sure to put it in your pocket each time you fly.

If you land off-field and exit the plane, you might be unable to go back into the plane to look for the beacon. If it is on your person, you won't have that problem. That's what was recommended by somebody who had the experience - if it is not on your person, you might not get the benefit of it.
 
airdale said:
FWIW, reports are that the SARSAT position reports for non-GPS-equipped ELTS are good enough to just send the SAR responder to the reported location, followed by little or no searching.

The advantage of the GPS-equipped ones is that the geostationary bird gets the location immediately. If not GPS-equipped, it takes a couple of passes of LEO birds to work out the location. IIRC this can take an hour or two.
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My personal opinion based on little other than understanding the system you mention is that the ELT better give all info in the first burst because there may not be a second. The ELT in the 'kota has a 50 second delay after activation so I figure that I better know that I'm in trouble at least 51 seconds before hitting anything really solid.
 
Well, your idea may have some validity. Credible numbers I have seen say that the ELT is operational about 60% of the time after a crash. Damaged antenna, dead batteries, severity of crash, ... etc. can keep it from working.

But my guess is that the SARSAT system has some threshold for messages in order to minimize false alarms. It may well ignore one or two messages received by the geosynchronous bird. Enough Googling would probably tell us, but I do not have the time to do it. You could also call AFRCC; they might know.
 
NoHeat said:
Be sure to put it in your pocket each time you fly.

If you land off-field and exit the plane, you might be unable to go back into the plane to look for the beacon. If it is on your person, you won't have that problem. That's what was recommended by somebody who had the experience - if it is not on your person, you might not get the benefit of it.
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We keep it velcroed to the roll bar in the back cockpit.

Our preplanned procedure in the event of engine failure (presuming there is time) is for the non-flying pilot to remove the strap, and Velcro the ELB to their wrist.

One scenario that we anticipate, given how much time we spend flying over uninhabited islands down here, is that we are tooling along at 2500' and the engine conks out. We land on the beach, clamber out, trigger the ELB, sip some water, find some shade, and await these guys: (They were showing off for Mary last night...). :)

upe4yzah.jpg
 
I heard a presentation by a rescue expert, I think it was Doug Ritter. They say that if it is not on your person, it won't exit the plane with you in an emergency. That's because you will be very excited, to the point of not thinking much at all.

So I put my PLB in my pocket before I fly.
 
One of the cheapest emergency devices you could carry is a signaling laser. No you don't want to be pointing it stuff but that is exactly what the Winslow life raft people will tell you to do. In the dark they can travel like 20 miles.
 
Want to offer an update... My ELT is well out of warranty and thus if my personal modifications do not resolve this very intermittent issue, I am on my own to replace it if I choose to.

What do I believe to be the issue? The non-shielded, non-twisted RJ11 wire that runs th length of the aircraft, effectively acting as an antenna.

What have I done so far? Replaced the RJ11 under the console between the alarm/battery module and the remote with shielded 4-conductor 24ga wire.

What will I do during next week's owner assisten annual? Replace the RJ11 between the ELT and the remote.

Once that is done, I truly hope my false alarms stop. My money is on this unshielded cable being the weak link in the system.
 
Think about your statement... An antenna receiving exactly, what? There are only a few other transmitters on board... Close enough to put that wire in their near-field. Are they spectrally clean or have a problem? Are they all properly single-point grounded? Are their coax cables run alongside the ELT wiring? Cheap/high-loss coax with wimpy shielding?

I'm finding it difficult to believe the ELT manufacturer designed the remote to use Cat III unshielded flat cable, and wouldn't know to put RF bypass capacitors on the jacks.

Just throwing some ideas out there.

If the ELT isn't triggering immediately after a transmission from the Comm, or transponder, what evidence is there that it's an RF induced problem?

If you really think it's RF, I'd be hunting for the bad ground or poor shielding on some other device, then. It takes quite a but of RF energy or noise to induce a significant voltage in a wire acting as an antenna. Can the ELT manufacturer tell you what the minimum voltage/current would be to trigger their activation circuit? Is it a simple switch circuit, or is the remote head actually sending something other than just a circuit closure?

Lots to think about.
 
Yes, lots to think about for THEIR engineers. Why? Because after countless emails between myself and ACK, the remote cable being unshielded is all they could come up with. They had me measure distances between all transmitting antennas and everything was within spec. They asked me to relocate the battery module "away from any cable bundles" to reduce the chance of interference or EMI. Then they informed me that only a select few aircraft benefitted from actually upgrading to CAT5 4-conductor shielded twisted pair between the ELT and the remote. I just got done installing that last week.

Why do you suppose they would have made all those suggestions in my case? I say that even if there is a remote chance of ANY aircraft having similar issues, why not just include the better quality shielded CAT5 to begin with? Only cost me $6.59 plus tax and shipping and I installed it myself during my owner assisted annual with my shop's supervision. Many questions yet unanswered, including whether or not this will stop all my false alarms.

If you don't hear from me for about 2 years and you are curious, send a private message and I will let you know how its going. I truly hope this resolves it long term, but won't be confident for at least one full year of flawless operation.

As for the previous posting related to PLB's versus ELT's, I too considered that. Then ACK came out with the A-04 at $600 range; including labor was about $1,200 to install. In order for my plane to travel to Canada and the Bahamas, it will soon be mandatory so I upgraded from 121.5. Even with the false alarms, I have no regrets. Besides, having been a member of CAP, I totally get the reduction of response time in the event of an accident.

As for the RJ11 antenna, I am growing tired of people questioning that fact. Have you ever seen the antenna on the back of a clock radio? Nuff said.
 
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