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Another ELT incident, AK-451

Walt

Walt

Well Known Member
Air Force Rescue Coordination center calls all my listed numbers this morning at 4am saying my ELT is going off :eek:

Freaked the wife out as she was away on business and gets a "wake-up" call asking if she knows where I am, so now my home and cell phone won't stop ringing.

I arrive at the hanger at 5am and sure enough it's going off.

Ameriking AK-451, it's going back to the factory tomorrow, after turning it off it passes the self test, it may not find its way back in my aircraft when I get it back.
 
There's a coin-cell battery in the remote display. When that battery runs down/dies, it triggers the ELT. This has happened to half a dozen airplanes locally. Ameri-King claims this is "not a problem with the ELT" and that the battery should last 10 years before this happens.

The real issue is that there is a leakage current problem in the remote display circuit somewhere. If you close your hangar door (or go in at night with the light off) you'll see that the LED in the remote display glows dimly, and you'll hear a faint buzzing from the piezo buzzer. These are what draw the coin cell battery down.

Oh, and also: My father sent his ELT in to Ameri-King to "fix" this. It's been four weeks now and they claim they can't find it, so he's got to buy another ELT anyway. It won't be an Ameri-King.
 
Snowflake said:
There's a coin-cell battery in the remote display. When that battery runs down/dies, it triggers the ELT. This has happened to half a dozen airplanes locally. Ameri-King claims this is "not a problem with the ELT" and that the battery should last 10 years before this happens.
Click to expand...

There is a battery replacement reminder for that lithium cell in the AmeriKing info. Luckily, I added that as an item in my Annual checklist. Only because of that I just replaced it this Spring. (IIRC, the AK info says to replace every six years.) Seems like everybody remembers to replace the D-cell batteries in the ELT itself, but many are not aware of the lithium cell in the panel remote.
 
Good info, in this case both the ELT and remote are about 3 yrs old so the batteries "shouldn't" be depleted yet.

Will be shopping for a Kannad at Osh this year.

Anybody want to buy a slightly used AK-451:rolleyes:
 
File a Service Difficulty Report (SDR) with the FAA.

If they get enough the problem will get fixed...:)
 
Snowflake said:
There's a coin-cell battery in the remote display. When that battery runs down/dies, it triggers the ELT.
Click to expand...

That seems like a really poor design. So, in effect, a low battery in the remote announces itself by having the ELT blast an emergency crash signal to the world!

Snowflake said:
The real issue is that there is a leakage current problem in the remote display circuit somewhere. If you close your hangar door (or go in at night with the light off) you'll see that the LED in the remote display glows dimly, and you'll hear a faint buzzing from the piezo buzzer. These are what draw the coin cell battery down.
Click to expand...

Rob, does this mean that we can work around the leakage current problem by simply replacing the remote's coin battery every year or so? If so, it would be a cheaper "solution" than having to completely replace the ELT.
 
Gunter Malich said:
Rob, does this mean that we can work around the leakage current problem by simply replacing the remote's coin battery every year or so? If so, it would be a cheaper "solution" than having to completely replace the ELT.
Click to expand...

It sounds like it. Depending on your unit, the buzzer may or may not be audible, which means it may or may not draw the power down faster. We were sitting at my father's hangar one day and I kept hearing the buzzing (from outside the plane, a Cessna 150, and about 10 feet away). It took 15 minutes to locate it, we couldn't believe it was the ELT panel. He disassembled the remote and disconnected the buzzer to stop the noise and reduce the power drain. The LED still glows though.

It's just bad design. Ameri-King indicated that they could fix this if the unit was sent in, hence the attempt at service. We didn't realize that "service" meant "buy another one because we lost the first one". :mad:
 
I've long stated in this forum that you get what you pay for when it comes to ELT's. Just like the Apollo astronauts who joked that they were sitting on a rocket made by the lowest bidder, one has to ask if it's a wise thing to bet your survival on the cheapest ELT you can find. This conversation thread is ample evidence that the Ameri-King ELT's are junk, plain and simple.

I contrast the experiences related here with my own experiences with a competitor's ELT. I own two of them personally and have installed at least 10 others of that brand. Several are five or more years of age. NONE of them have had a single problem of any nature. None, zip, zero, nada. When I have asked two shops who do a lot of the Canadian-mandated annual shop recertifications what their experiences were with this same brand, the answers were the same. The only ones they get back for "repair" are ones where the operator, either by miswiring the remote switch or inadvertently turning the remote switch to the "on" position, caused depletion of the battery.

All of this to say there IS a better mousetrap available, but you need to be willing to pull another few hundred out of your wallet to get it. It's up to you to figure out how much your life and the lives of your passengers are worth.

OK, I'm stepping off my soapbox now...
 
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Canadian_JOY said:
All of this to say there IS a better mousetrap available, but you need to be willing to pull another few hundred out of your wallet to get it. It's up to you to figure out how much your life and the lives of your passengers are worth.
Click to expand...

I agree, and it's called a PLB. I think a lot of us install an ELT to be rule compliant, but carry a PLB/GPS to save our bacon should the need arise. ELTs have a poor record for working post accident, or sinking, or burning, or...

I'd really rather be picked up and back home within hours versus re-creating a "Man vs. Wild" episode.
 
fl-mike said:
I agree, and it's called a PLB. I think a lot of us install an ELT to be rule compliant, but carry a PLB/GPS to save our bacon should the need arise. ELTs have a poor record for working post accident, or sinking, or burning, or...

I'd really rather be picked up and back home within hours versus re-creating a "Man vs. Wild" episode.
Click to expand...

The PLB is an excellent device to carry ON YOUR PERSON, as a backup to an ELT. They can't replace an ELT because no PLB has an automated activation feature equivalent to the ELT's G-switch.

Without question, the best odds of survival go to the pilot who does not rely on a single distress alerting device. The ELT is a mandatory requirement for many aircraft. Back it up with at least something else. A PLB, a SPOT tracker, a Spidertracks unit, a DeLorme InReach device - all of these are good options. Add a fully charged cell phone to the mix, as well as a handheld VHF with fully charged batteries. A signal mirror is low-tech and works well to attract attention. Last but not least, the lowly flight plan can save your bacon (particularly helpful in Canada where VFR flight plans seem to play a much more active role in SAR notification.

Please note that, while we have the perception that ELT's "don't work", many of these perceptions are based on stories from 40 years ago. That's sort of like saying communications don't work because HF radio goes wonky during sunspot activity (while ignoring the good VHF comms we now have, not to mention cell phones and satphones!). If we look at CURRENT ELT activation results, differentiated so we can see actual 406 ELT activations, we'll find they have improved quite a bit.
 
For what it's worth, despite my opinion of the 406MHz units, I understand that Ameri-King's 121.5 units are widely regarded as reliable units. My -6 came with one, and it's been trouble-free for the last 5 years.

I do carry a SPOT as well, for pilot-activated response. I don't believe that I won't see an emergency in time to activate the alert on the SPOT... If the emergency happens so fast that i'm incapacitated to the point of not being able to, it's highly likely that I haven't (or won't) survive the event anyway.
 
How did you test it?

Snowflake said:
For what it's worth, despite my opinion of the 406MHz units, I understand that Ameri-King's 121.5 units are widely regarded as reliable units. My -6 came with one, and it's been trouble-free for the last 5 years. .
Click to expand...

Coincidently, I'm in the middle of my annual condition inspection. My Ameri-King 121.5 ELT tested "fine" (using the panel test switch) - that is until Walt had me pull the unit out to check the G-switch.

Just a small G load (a quick push and stop while in my hands) caused the unit to activate. I'm surprised that it never went off while flying.

Needless to say, I'm replacing it ... and not with Ameri-King.
 
Rob - not to be too argumentative, however the evidence I've seen is contrary to your statement. The Ameri-King 121.5 ELT's are some of the poorest of the bunch when it comes to C91a ELT's, as are the whip antennas they came with. One shop that does lots of ELT certifications reports close to a 50% failure rate of the 121.5 units. I've personally replaced 3 of the whip antennas which broke off... in flight! I remember each of them because it's always a miserable job crawling into the tail to get at the little devils.
 
My ELT fires off when I transmit on the higher frequencies. I guess it's not an uncommon complaint with the ACK's. Of course my home airport is 135.00... Rather than hitting the reset button every time I talk to the tower I have to leave it off.
 
If your ELT is activating at higher frequencies, you can do a few things to help reduce the probability of this occurring.

First, the ACK telephone cord wiring is not shielded. You can replace it with shielded cable and you can bond the shield to ground (external to the telephone jack connector). That can be a lot of work. The alternative is to ensure the telephone cord doesn't run parallel to other wiring, and particularly coax cables. If possible, the coax and telephone cord should cross each other at 90 degree angles. The coax cable always leaks a little energy; if the telephone cord runs parallel to the coax, that "leaked" energy will couple into the telephone cord. It's this leaked energy that's interpreted by the ELT as a command to turn "on".

You can also snap a ferrite bead over the telephone cord near where it enters the ELT - this will help tame some of the energy that's been picked up in the cord, but is not nearly as effective as ensuring proper routing and shielding.
 
Battery SPEC Please

Snowflake said:
It sounds like it. Depending on your unit, the buzzer may or may not be audible, which means it may or may not draw the power down faster. We were sitting at my father's hangar one day and I kept hearing the buzzing (from outside the plane, a Cessna 150, and about 10 feet away). It took 15 minutes to locate it, we couldn't believe it was the ELT panel. He disassembled the remote and disconnected the buzzer to stop the noise and reduce the power drain. The LED still glows though.

It's just bad design. Ameri-King indicated that they could fix this if the unit was sent in, hence the attempt at service. We didn't realize that "service" meant "buy another one because we lost the first one". :mad:
Click to expand...

What is the coin battery SPEC or ID for the panel remote so I can get one before I go to the hangar? The math works better for me than the ELT replacement. Also perhaps less expensive than this https://www.youtube.com/watch?v=p-cIpmgsbac

EDIT: Duracell DL1/3NB 3 Volt Lithium Battery is THE battery for the AK 451 panel remote switch.
 
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Canadian_JOY said:
If your ELT is activating at higher frequencies, you can do a few things to help reduce the probability of this occurring.

First, the ACK telephone cord wiring is not shielded. You can replace it with shielded cable and you can bond the shield to ground (external to the telephone jack connector). That can be a lot of work. The alternative is to ensure the telephone cord doesn't run parallel to other wiring, and particularly coax cables. If possible, the coax and telephone cord should cross each other at 90 degree angles. The coax cable always leaks a little energy; if the telephone cord runs parallel to the coax, that "leaked" energy will couple into the telephone cord. It's this leaked energy that's interpreted by the ELT as a command to turn "on".

You can also snap a ferrite bead over the telephone cord near where it enters the ELT - this will help tame some of the energy that's been picked up in the cord, but is not nearly as effective as ensuring proper routing and shielding.
Click to expand...

When I bought the plane ten years ago and it had this problem I asked ACK and looked around on some forums. The "Fix" was to install the ferrite beads on the cable but it never worked. Maybe a shield on the phone cable would be worth a try. There's so little room to work with and I'm dealing with composite, so all the energy goes everywhere. It wouldn't be too hard to slide a braided shield down the wire, it only goes a few feet. Thanks.
 
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