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

[Bill Watson]

So, I'm parked at Greater Pittsburgh (KPIT) for a few days (great people there at Atlantic, will post about that separately). I get a call from Captain Somebody in Florida asking whether I'm the owner of my RV10. Uh oh.

He tells me that my ELT is sounding off and wants to know whether I was flying it and whether I was okay. I explained that it was parked safe and sound as far as I knew but I immediately thought, "What the hell has happened to my plane? A fuel truck ran into it, a PC-12 shredded it, the de-ice truck boom fell on it?".

I tell the good Captain that I'll look into it and get back to him. My mother, whom I'm visiting, is motioning to me that my wife is on the other phone. Turns out she got the call from Captain Somebody first because she is listed as my emergency contact! At first she thought the call was something other than real until the Captain told her that he would try my number and get back to her if unable to contact me.

Fortunately my wife didn't panic nor was she overly concerned. She knew I had been on the ground overnight and had no intention of flying that particular day. Whew! But I didn't expect her to get the first call since normally she would be in the plane with me. But the good Captain Somebody, or perhaps Capt. Somebody Else explained that she is listed as the emergency contact so she gets the first call. Will have too look into my ELT profile and the options there; who gets the 2nd and 3rd calls?

What set the ELT off? I called up Atlantic and they said they were unaware of any incidents. They sent a mechanic off to look and he reported all looked fine. They said the Ops Mgr would take a second look and they would get back to me. There seemed to be no possibility of anything having hit the plane or anything. It became clear that I would need to get out there in person, inspect and do whatever was required to turn off the ELT signal.

This is an ACK 406 unit. When I got there the panel was blinking and beeping but it would not respond to the 'off' switch. I had to get to the unit and manually turn it off. A diagnosis will follow but at this point I have no idea what happened.

Did I say that all this occurred in typical 2014 Pittsburgh weather - a driving rain storm that changed to sleet then snow during my ramp expedition? Crikey I don't miss the 'burgh's weather!!

Has anyone else had this happen with an ACK 406MHz unit?

 

[Fearless Tower]

Did you have a harder than usual landing when you arrived?

 

[Bill]

Crikey I don't miss the 'burgh's weather!!

I grew up right under the approach to 28R, about at the two mile final point. I love going back to visit, but only in the summer.

 

[bnt83]

Has anyone else had this happen with an ACK 406MHz unit?

No but, I've worked at a heavy shop for about 7 years and one of the first things I noticed as a new hire was how often electronics fail. PC boards, displays, computers, switch panels you name it, they all fail. Fortunately for the GA guys when a box fails it's not a stand alone DME receiver that cost $10k exchange.

 

[Bill Watson]

I grew up right under the approach to 28R, about at the two mile final point. I love going back to visit, but only in the summer.

I usually fly into KAGC where I first took lessons but I spent a lot of time around KPIT. Watching planes at the old terminal (Lot's of TWA Connies and DC3s at the time). Sitting among the approach lights watching landing planes (14 perhaps or 28). Flying RC about 10 miles away near Burgetstown (sp).

Finally flying myself in there was nostalgic. Flying vectors to the 28L ILS I flew over downtown near where I used to sit on my front steps and watch the airliners intercept the localizer for what is now 28R. The airport is now giant but deserted. Three parallel runways but I'm guessing that 28C barely gets used. Taxiing in, I began to recognize the outlines of the old airport as I got closer to Atlantic. Turns out Atlantic is built right on top of the old terminal. Lot's of memories even though everything obvious is gone.

BTW, the landing was smooth despite gusting winds and all. Nothing to suggest that the ELT be activated.

 

[flyingron]

Dying battery in the remote? I've found my older non-406 unit would go wonky in such situations.

Watch those hard landings I had a rental 172 in Australia once and noticed the ELT was missing. Seems one of the regular renters had removed it because it kept going off when he landed.

 

[bnt83]

Those batteries get missed often.

 

[Fearless Tower]

Watch those hard landings I had a rental 172 in Australia once and noticed the ELT was missing. Seems one of the regular renters had removed it because it kept going off when he landed.

We get false alarms a lot with Navy helos, usually after hard landings.

 

[NavAir]

RCPI battery weak/dead/corroded. Has happened before...

 

[Bill Watson]

Dying battery in the remote? I've found my older non-406 unit would go wonky in such situations.

Watch those hard landings I had a rental 172 in Australia once and noticed the ELT was missing. Seems one of the regular renters had removed it because it kept going off when he landed.

Those batteries get missed often.

RCPI battery weak/dead/corroded. Has happened before...

Haven't given the remote battery a thought. Will check. Should have years of life left but who knows. Thanks!

 

[JSumeracki]

Yes, this has happened to me THREE times since upgrading to my ACK A-04 406 ELT less than 2 years ago (during my plane's IFR re-cert).

First time, like your situation, happened on the ramp. My son and I had flown about an hour in perfect VFR to a $100 hamburger. I received a phone call and initially ignored it because it was a Saturday morning and an unknown area code. When the airport manager came to tell be the Air Force wanted to talk about my ELT, I set down my sweet tea and immediately called them back.

The ELT was going off, but there was no "alarm" and the LED was not flashing. I hit reset and that was the end of it... for a while!

Second time I was IFR (due to distance and flying 80nm over Lake Michigan) in beautiful smooth VFR air. My ELT went off in mid-air and with regret, I was not monitoring 121.5 on this particular flight. Again, no LED, no audible alarm. By the time I got low enough to be in cell phone range, I started hearing non-stop text message alerts in my Bluetooth enabled Zulu headset. My ELT was going off and the Air Force had already contacted my wife and my employer, so I had tons of people worried hat I had ditched in the lake (yes, I had a lifevest within reach). Then ATC called me to inform it was active. I tuned into 121.5 and sure enough, there was the analog. I reset the ELT in mid-air and it stopped. Upon landing, I spent 40 minutes on the phone sorting it all out.

For the record, I worked on weapons systems electronics in the Navy and for 22 years have serviced advanced medical imaging equipment, so I'm no stranger to electronics. I'm also a computer enthusiast. So after that event, I called ACK tech support in San Jose, CA. They informed me this NEVER happens (yea, right) and then proceeded to troubleshoot. We ultimately found that the CR2 3VDC lithium battery in the remote controller (mounted under the console and near the remote switch, connected with RJ11 phone cables) had leaked lithium "juice" and had shorted the circuit. I cleaned it all up (electronics guy, contact cleaner, etc), tested OK with a brand new battery from Wallgreens. ACK sent me a replacement anyhow due to corrosion on the battery terminal. The replacement made no difference; the LED and alarm now work.

Fast forward to this morning. I run a flying club. I was at home and the Air Force called me. My ELT was going off at my home airport (KJQF). I knew one of my pilots had filed an IFR flight plan (via FlightAware auto notification) so she must have been departing. The ELT apparently went off soon after departure because she did not notice it until landing.

Without getting into more details, that's 3 strikes against the ELT, I have already DEMANDED in no uncertain terms a replacement of the entire unit. I have a friend who owns a Piper Arrow and just got the same ELT installed and has already had two false alarms himself. There is no way that ACK can say this is unique to me. I would advise any other pilots that have this problem to report it immediately. It is quite possible there is a design flaw in the unit(s) and this could, if enough pilots complain, lead to a recall.

That's my two cents, thanks for posting your story.

 

[JSumeracki]

A couple other notes before I get hammered...

(1) YES the operator's manual calls for regular testing of the remote control panel (verifying audible alarm and LED function) and YES I neglected that a couple times.

(2) While there is no penalty for false alarms, if the Air Force keeps getting hammered with a 90% false alarm rate from these NEW 406MHz ELT's, you can bet your bottom dollar the FAA will find a way to start (much like false alarms with home security systems). WE NEED TO REPORT THESE ISSUES TO THE MANUFACTURER(s) for our own collective good.

(3) The Air Force has now requested that myself and all pilots DISABLE the ELT (turn switch from Active to OFF) while my aircraft is (a) not in a hangar, and (b) anywhere other than its home field for an extended period of time. This is so that there is no chance of the ELT actvating while unattended. This is unacceptable long term, of course, hence the reason I have demanded warranty replacement of the ELT. (Imagine a microburst hauling my plane up and throwing it into the FBO - I'd like the ELT to go off, actually!)

 

[MAKG1]

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.

 

[Bill Watson]

(3) The Air Force has now requested that myself and all pilots DISABLE the ELT (turn switch from Active to OFF) while my aircraft is (a) not in a hangar, and (b) anywhere other than its home field for an extended period of time. This is so that there is no chance of the ELT actvating while unattended. This is unacceptable long term, of course, hence the reason I have demanded warranty replacement of the ELT. (Imagine a microburst hauling my plane up and throwing it into the FBO - I'd like the ELT to go off, actually!)

Thanks for the update Jeff.

Disabling the ELT when parked is not practical in my RV10 installation. It's just not easily accessible.

I have not had any other activations since the one.

Key point; someone at ACK said that if moisture reaches the orange remote buzzer thing, they've found that it can set the unit off. Whether true or not I don't know but the one activation did occur during a driving ran/sleet storm and my vents were open. There was a possibility of such moisture getting to the unit.

What I did was partially wrap the unit with some self fusing silicone. I didn't seal it up completely to prevent condensation problems. Don't know if helps or not but so far so good. And it's been tied out in some driving rain conditions since then.

 

[Henning]

Yes, this has happened to me THREE times since upgrading to my ACK A-04 406 ELT less than 2 years ago (during my plane's IFR re-cert).

First time, like your situation, happened on the ramp. My son and I had flown about an hour in perfect VFR to a $100 hamburger. I received a phone call and initially ignored it because it was a Saturday morning and an unknown area code. When the airport manager came to tell be the Air Force wanted to talk about my ELT, I set down my sweet tea and immediately called them back.

The ELT was going off, but there was no "alarm" and the LED was not flashing. I hit reset and that was the end of it... for a while!

Second time I was IFR (due to distance and flying 80nm over Lake Michigan) in beautiful smooth VFR air. My ELT went off in mid-air and with regret, I was not monitoring 121.5 on this particular flight. Again, no LED, no audible alarm. By the time I got low enough to be in cell phone range, I started hearing non-stop text message alerts in my Bluetooth enabled Zulu headset. My ELT was going off and the Air Force had already contacted my wife and my employer, so I had tons of people worried hat I had ditched in the lake (yes, I had a lifevest within reach). Then ATC called me to inform it was active. I tuned into 121.5 and sure enough, there was the analog. I reset the ELT in mid-air and it stopped. Upon landing, I spent 40 minutes on the phone sorting it all out.

For the record, I worked on weapons systems electronics in the Navy and for 22 years have serviced advanced medical imaging equipment, so I'm no stranger to electronics. I'm also a computer enthusiast. So after that event, I called ACK tech support in San Jose, CA. They informed me this NEVER happens (yea, right) and then proceeded to troubleshoot. We ultimately found that the CR2 3VDC lithium battery in the remote controller (mounted under the console and near the remote switch, connected with RJ11 phone cables) had leaked lithium "juice" and had shorted the circuit. I cleaned it all up (electronics guy, contact cleaner, etc), tested OK with a brand new battery from Wallgreens. ACK sent me a replacement anyhow due to corrosion on the battery terminal. The replacement made no difference; the LED and alarm now work.

Fast forward to this morning. I run a flying club. I was at home and the Air Force called me. My ELT was going off at my home airport (KJQF). I knew one of my pilots had filed an IFR flight plan (via FlightAware auto notification) so she must have been departing. The ELT apparently went off soon after departure because she did not notice it until landing.

Without getting into more details, that's 3 strikes against the ELT, I have already DEMANDED in no uncertain terms a replacement of the entire unit. I have a friend who owns a Piper Arrow and just got the same ELT installed and has already had two false alarms himself. There is no way that ACK can say this is unique to me. I would advise any other pilots that have this problem to report it immediately. It is quite possible there is a design flaw in the unit(s) and this could, if enough pilots complain, lead to a recall.

That's my two cents, thanks for posting your story.

Dang, thanks for the warning, probably won't be long before the USAF demands a recall.

 

[wsuffa]

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.

Sorry, wrong answer.

This is a manufacture and certification problem. That's where and how it needs to be addressed. And it's not just ACK, I have had issues with an Ameriking. These devices are a lot less reliable than the 121.5 units.

The boxes are government-mandated, there should be a process for dealing with it in certification.

 

[MAKG1]

Sorry, wrong answer.

This is a manufacture and certification problem. That's where and how it needs to be addressed. And it's not just ACK, I have had issues with an Ameriking. These devices are a lot less reliable than the 121.5 units.

The boxes are government-mandated, there should be a process for dealing with it in certification.

No. Not the wrong answer. Read EXACTLY why Mr. Sumeracki wants to leave it on when parked.

Neither the Air Force nor CAP is a notification service.

There is a problem with the units. There is also a problem with a selfish owner who thinks volunteer time is worth nothing, especially when it can mask actual emergencies.

It's a good bet the Air Force is already making a lot of noise, as a billion false alarms degrade capabilities.

 

[Clark1961]

No. Not the wrong answer. Read EXACTLY why Mr. Sumeracki wants to leave it on when parked.

Neither the Air Force nor CAP is a notification service.

There is a problem with the units. There is also a problem with a selfish owner who thinks volunteer time is worth nothing, especially when it can mask actual emergencies.

It's a good bet the Air Force is already making a lot of noise, as a billion false alarms degrade capabilities.

So did you eat a double helping of grumpy-flakes for breakfast?

SOP is to leave the ELT switch armed...and a facetious comment by someone that they want notification won't change that one bit.

 

[MAKG1]

So did you eat a double helping of grumpy-flakes for breakfast?

SOP is to leave the ELT switch armed...and a facetious comment by someone that they want notification won't change that one bit.

You need to think for a bit what it means for an ELT to go off unattended. If it's an accident, that's fine. If it's because the owner doesn't care, that's not fine at all.

Maybe you should try locating one of these before you treat it as so trivial.

 

[Palmpilot]

...(3) The Air Force has now requested that myself and all pilots DISABLE the ELT (turn switch from Active to OFF) while my aircraft is (a) not in a hangar, and (b) anywhere other than its home field for an extended period of time. This is so that there is no chance of the ELT actvating while unattended. This is unacceptable long term, of course, hence the reason I have demanded warranty replacement of the ELT. (Imagine a microburst hauling my plane up and throwing it into the FBO - I'd like the ELT to go off, actually!)

Is the Air Force asking this for all ELTs, or just this make and model?

 

[Tim]

Lets just git rid of them!

 

[Clark1961]

You need to think for a bit what it means for an ELT to go off unattended. If it's an accident, that's fine. If it's because the owner doesn't care, that's not fine at all.

Maybe you should try locating one of these before you treat it as so trivial.

So what part of an aircraft being destroyed on a ramp is not an accident?

I did my time in CAP so I know what it means for an ELT to be set off. Maybe you need to tone down your attitude and re-evaluate your commitment and what it means.

 

[Henning]

So what part of an aircraft being destroyed on a ramp is not an accident?

I did my time in CAP so I know what it means for an ELT to be set off. Maybe you need to tone down your attitude and re-evaluate your commitment and what it means.

Besides, of it happens on an airport, then there won't be an SAR required, they make a phone call, you answer, end of story.

 

[Dan Thomas]

The ACK E-04, unlike the Artex and some others, uses an unshielded remote cable that can pick up stray RF or other electromagnetic interference from Comm antennae or strobes or alternator output cables or whatever. Their manual warns against running that line anywhere along such lines. The older 121.5 ACKs had a habit of triggering sometimes when transmitting on some VHF frequencies; I had one in a 172 that did it even after swapping out an identical unit from another airplane. Finally stopped it by wrapping the remote cable, at the ELT end, a couple of times through a split ferrite core to choke off the stray RF.



The ACK costs less, but such bad habits make it cost more.

Dan

 

[wsuffa]

You need to think for a bit what it means for an ELT to go off unattended. If it's an accident, that's fine. If it's because the owner doesn't care, that's not fine at all.

Maybe you should try locating one of these before you treat it as so trivial.

I chased any number of 121.5 ELTs when it was much harder to locate (before SARSAT). Granted that it's not a lot of fun at 3 AM. These days, the 408 units are much easier to locate.

That said, IMHO it is irresponsible to suggest that pilots switch them off as a matter of routine after landing, particularly with a club or rental fleet. How many will get left "turned off" when flying, resulting in more deaths due to unheard beacons. Further, the issue with my Ameriking was such that turning the unit off from the panel switch would have made zero difference. If the problem is stray RF triggering, it's entirely possible that turning it off will not resolve the problem.

This problem needs to be resolved at the certification stage. If we have an abundance of units that are "falsing" or draining batteries, or otherwise malfunctioning, then the certification standards are bad, and neither the buyer nor the volunteer, nor the government will ever really know if the unit will function as intended. Certification is supposed to provide some level of confidence that the equipment will perform as intended - if the device meets certification, then the manufacturer has one form of defense against lawsuits.

 

[Henning]

The standards were probably designed by committee. I remember Chooch (Everett Alsenz) telling me about being approached by the USAF about making the original ELT units during IIRC Vietnam. He asked them how this deal was possible without competitive bidding and all the rest. "We don't have the time for that, and we need them to work."

 

[RV10flyer]

Thanks for the update Jeff.

Disabling the ELT when parked is not practical in my RV10 installation. It's just not easily accessible.

I have not had any other activations since the one.

Key point; someone at ACK said that if moisture reaches the orange remote buzzer thing, they've found that it can set the unit off. Whether true or not I don't know but the one activation did occur during a driving ran/sleet storm and my vents were open. There was a possibility of such moisture getting to the unit.

What I did was partially wrap the unit with some self fusing silicone. I didn't seal it up completely to prevent condensation problems. Don't know if helps or not but so far so good. And it's been tied out in some driving rain conditions since then.

No kidding on the accessibility....30 something screws in and out of our rear baggage bulkhead.

I have an Ameri-King 406 with panel remote, phone line interconnect and all is well so far. Almost 3 yrs old.

Bulb Grease or Dielectric Grease is what I used on many of my electrical connections during the build. No problems so far with corrosion or conductivity. This product can be purchased at your local auto parts store and may help any of you with low voltage electrical connections where you want to keep moisture out. I use it on all of my vehicles too.

 

[Silvaire]

No kidding on the accessibility....30 something screws in and out of our rear baggage bulkhead...

The installations I've seen on some of these things leaves me wondering WTF were they thinking? I mean it's quite conceivable to imagine a forced landing somewhere, the nose gear busts off and the plane flips over on it's back. Nobody is hurt but now you need tools to get to the ELT so you can attach that antenna that is neatly strapped to it in an inaccessible location?

Doesn't make sense especially considering that the installation manual quite explicitly tells you that the airframe mounted antenna must be withing a specific number of degrees from vertical. Just try to keep that in mind when you crash

 

[RV10flyer]

That is one reason why I keep a razor knife velcroed under the left side of my panel. The knife or a sharp rock can easily penetrate our aluminum skin to gain access to our ELT. The other use is for cutting seatbelts. My ELT antenna is mounted on the crossbar behind the rear seats. If it gets destroyed, there will probably be no need for the "rescue" part anyway.

 

[Silvaire]

...My ELT antenna is mounted on the crossbar behind the rear seats. If it gets destroyed, there will probably be no need for the "rescue" part anyway.

I'm not sure I follow what you're saying. The airframe mounted external antenna itself is pretty vulnerable and completely worthless if the airframe flips, as is common in a crash and may occur at the last moment and may not result in any injury to the occupants.

Your point about the knife, or even better a crash axe of some sort is a good one because really, after a crash who needs a tool to carefully remove screws to access the ELT?

 

[Bill Watson]

I "followed the book" on my installation in the RV10. The main unit is mounted to a pad behind the baggage compartment. The antenna sticks out of my tailcone, vertical and all that. I didn't try to hide it from the airstream and all.

Yep, there are about 20-30 screws required to get to the main unit in order to disable it upon landing. That's not going to happen and no one should expect it to.

Anyone who followed ACK's certification journey might surmise that manufacturers are between a rock and hard place. Certification against an international standard looks tough. ACK had to sit on a year's worth of finished inventory awaiting various approvals from various countries against various details of the product and it's certification. ACK's fault or the process's fault or just par for the course? I don't know but I'm not surprised at some startup issues for this new technology.

Of course, I recall ACK being the low price supplier when I was looking. But what other criteria is available to make such a decision on a required piece of equipment.

 

[tmyers]

As much as they cost, they should have coffee waiting for you when you arrive at the hangar.

I have been hearing that the 408 units will change the roll of CAP anyway since the GPS in them give a precise location of the signal.

What is there to go find?

Edumacate me!!!

 

[Clark1961]

As much as they cost, they should have coffee waiting for you when you arrive at the hangar.

I have been hearing that the 408 units will change the roll of CAP anyway since the GPS in them give a precise location of the signal.

What is there to go find?

Edumacate me!!!

406 ELTs don't require GPS but they can incorporate a GPS position. The numbers reported by one manufacturer (Emerging Lifesaving Technology) suggest a 1 km radius search area for a stand-alone 406 signal. Adding GPS reduces the radius to 100 yds. Of course 100 yds search radius is not necessarily air search type of uncertainty depending on terrain.

I looked at options and the terrain I fly over and decided I wanted an ELT with built-in GPS since that had the best chance of reporting an accurate position after arrival.

 

[Henning]

406 ELTs don't require GPS but they can incorporate a GPS position. The numbers reported by one manufacturer (Emerging Lifesaving Technology) suggest a 1 km radius search area for a stand-alone 406 signal. Adding GPS reduces the radius to 100 yds. Of course 100 yds search radius is not necessarily air search type of uncertainty depending on terrain.

I looked at options and the terrain I fly over and decided I wanted an ELT with built-in GPS since that had the best chance of reporting an accurate position after arrival.

Does yours couple to the plane's GPS, have an internal GPS, or both?

 

[gismo]

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.

I don't want you to get up in the middle of the night (or even in the middle of the day) to respond to a failed ELT in my airplane but I can't turn it off when I park the airplane unless I want to spend an hour before and after each flight removing and replacing the aft bulkhead.

 

[denverpilot]

FAA Certification strikes again, eh? LOL

 

[Silvaire]

I don't want you to get up in the middle of the night (or even in the middle of the day) to respond to a failed ELT in my airplane but I can't turn it off when I park the airplane unless I want to spend an hour before and after each flight removing and replacing the aft bulkhead.

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.

 

[Clark1961]

Does yours couple to the plane's GPS, have an internal GPS, or both?

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

 

[wsuffa]

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.

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.

 

[Dr. O]

Lots of grumpy flakes today.
If false alarms become a burden then likely the FAA will mandate that ELT units be located for immediate access from the pilot seats and be turned off when the aircraft is not in use.
As far as lives lost because the ELT was not turned back on and the plane crashed without anyone noticing and the people languished for hours or days and then perished, I suspect this is such a minor percentage that it falls into the lightning strike catagory - and can be managed through regulation by an ELT arming signal that is tied to the master switch (yet another transistor to go poof).
And as a society I suppose we will then mandate an ELT like device on every auto and truck (ala OnStar)
Of course the evolution of perfect safety is to have every flight and every auto movement and every boat movement be under positive control that way we will know when they crash and grumpy flakes won't have to get out of bed at 3 AM for a false alarm, eh..
If you detect a note of sarcasm, well (shrug)