Jump to content
Sign in to follow this  
Bill3558

Bad ELT?

Recommended Posts

My SLA plane is getting its annual. Was informed yesterday my ELT is not working, and that I need to start shopping for a new one. Have any of you guys had this problem? Are they serviceable?  He said it’s probably the switch. 
Thanks, appreciate  any advice. 

Share this post


Link to post
Share on other sites

If you have a bad 121.5 ELT you are not supposed to fix it. You have to go to a 406 ELT. No one pays attention to 121.5 Elt signals anymore anyway.

We had a guy crash on takeoff at night in a 150,  the 121.5 signal ran for 5 days with no response. No one knew he had left so he was not missed. I have informed KCHS TRACON several times of a strong ELT signal but they didn't  respond. Most of them are in error.

Share this post


Link to post
Share on other sites

Most 121.5 ELT's are repairable, but it is like throwing good money away for bad. The Ameri King AK-450 ELT that was installed in most of the CT's has an Airworthiness Directive that say if it is broke you can't fix it and it must be replaced. Kannad makes an Ameri Fit ELT that makes installation fairly easy. The only problem is that it is pricy, and does not come with an antenna. ACK is the least expensive, but they seem to have issues with mysterious activations. I think I would go with a Artex 345 kit if it were my airplane.

Share this post


Link to post
Share on other sites

Satillites no longer monitor 121.5. I have installed many ACK's with no issues. Some people install them incorrectly and have issues. I had one owner who decided to install it himself with the  wrong metal label  so that when he pressed reset/test he was actually pressing the on button.

Share this post


Link to post
Share on other sites

I still have my old 121.5 unit in my CT, but I keep a 406 PLB in the foot well storage.  It requires manual activation, but at least I have some 406 SAR capability. 

I'm cheap, so I will put off the ELT upgrade until it's required or fails.

Share this post


Link to post
Share on other sites

For those who have the old Ameri-King ELT make sure that the AD is being complied with and logged in the aircraft records. I have come across a few airplanes where the AD had been missed by other mechanics or light sport repairman. 

Share this post


Link to post
Share on other sites

I will probably go with the ACK elt, I've installed a lot of them. It's unusual to install the antenna on the bottom of the fuselage, as it goes against FAA requirements. I guess they figure you will be upside down in a CT. I did some GPS signal tests a while back and found no degradation when the antenna was installed inside the fuselage which I thought was unusual for carbon fiber. Maybe something to look at.

Share this post


Link to post
Share on other sites

I switched from a 121.5 Ameri-King to a 406 ACK ELT a couple years ago, then had a spontaneous in-flight activation a few months ago while on a trip back east.

The plane had set outside on the ramp at Elmira, NY through a couple days of heavy rain. There was about an inch of water in each of the foot lockers which I sponged out before flight. About 45 minutes into the flight, I heard the whoops of the ELT on the comm radio, even though it was set to a Unicom frequency. Apparently, the proximity of the ELT and comm antennas, or their coax cables, allows frequency crossover.

Pushing the reset button on the ELT remote provided only momentary relief. I landed at the nearest airport, Warren Eaton, and disconnected the battery compartment from the rest of the ELT main unit to insure it would not broadcast again (the OFF position on the switch on the ELT main unit, as opposed to ARM or ON positions, undoubtedly would have achieved the same thing, but nothing I tried from the remote was successful).

ACK suggested that the system is susceptible to spontaneous activation when the remote, audio alert or RJ11 telephone cabling is wet. They also indicated that battery acid corrosion in the remote or audio alert, specifically with Duracell batteries, could also be the problem.

After putting the unit back together at home a couple weeks later, it was still stuck ON. Even after replacing the remote, it was still misbehaving, though in a different mode. At that point I opened the audio alert and found corrosion on the Duracell battery. Replacing the battery and even bypassing the remote, did not seem to completely solve the problem at first, but a week later, with the audio alert still bypassed, the system was working fine.

A further note of possible of interest, though not central to the ELT discussion, is what happened as a consequence of the ELT activation. After landing and deactivating the machine, I was wondering who to call to ensure that no one was searching for me. A nice gentleman at the airport, giving young eagle rides with a beautiful red Maule, suggested I call 1-800-WXbrief, the FSS stand-in, and tell them what happened. I did. They said they would take care of it. Hours later, before landing back at Elmira, I started getting text messages from my wife asking if I was alright. Then when I landed, the FBO handed me a note with a phone number to call. It was the Air Force search and rescue operation in Florida! They hadn’t sent anyone out looking for me yet, but they were going to. Furthermore, they had called my wife, 2000 miles away, asking if she knew anything about an emergency signal from my aircraft!!! That did not go over well.

My conclusions:

1)      Our planes are not waterproof and should not be exposed to sustained heavy rain.

2)      My ELT seems to have suffered from both battery corrosion in the audio alert and from water in the RJ11 cabling, which finally dried out a week after I replaced the remote and bypassed the audio alert, many weeks after the initial water exposure.

3)      The audio alert is not needed in flight. Our own ELT broadcasts can be heard, loudly, on any radio frequency. Furthermore, the audio cannot be heard over background cockpit noise or with noise canceling headsets anyway.

4)      Make sure you disengage the Air Force after an inadvertent ELT activation. 1-800-WXbrief is apparently not the way to do it.

5)      Use someone other than your wife as your emergency contact.

Share this post


Link to post
Share on other sites

Thanks for the information. I had never thought about what to do for a false ELT alert. This is what I found after a quick search:


If the ELT is accidently activated, cancel the false alert by calling the U.S. Air Force Rescue Coordination Center at 1-800-851-3051 or the nearest Federal Aviation Administration Air Traffic facility and provide the beacon’s hex ID.

Also, looks like it would be a good idea to call your contact person and let them know you have a false alert and that you have contacted the proper authorities.

Share this post


Link to post
Share on other sites

Some ELTs won't fully activate either until after 50 seconds or so. Artex ones are like this. They'll start the initial beeping alerts to try and get your attention to the ELT activation, but after the delay the sound will change, lights will flash in a pattern on the face of the unit, and it will begin transmitting coordinates.

This is how they are tested per instructions: within that window.

Share this post


Link to post
Share on other sites

Time to get rid of ELT's, there are a lot of calls for that. They have a poor record even with 406. It's easier to find an aircraft through ADSB tracking. A lot has changed since the 1970's with communications and navigation.  Maybe it should be an option in remote areas. If you go down in Florida an alligator will probably get you first anyway. 😁

Share this post


Link to post
Share on other sites

Cubs, gliders, and others don't have and won't have ADS-B out.  The plane I'm building won't.  I'm not arguing in favor of ELT, which I'd rather not have, either.  If ELT is optional, it will be challenged for the cost-effectiveness of monitoring considering the few installations.

The question is, do we need Hale Boggs and if so in what form?  

Share this post


Link to post
Share on other sites

If the aircraft has never had  an engine driven electrical system. If a legal electrical system has ever been installed you need ADSB If you operate in controlled airspace. My issue is it must be a PITA to convey that info to ATC each time.

Share this post


Link to post
Share on other sites
22 minutes ago, Madhatter said:

If the aircraft has never had  an engine driven electrical system. If a legal electrical system has ever been installed you need ADSB If you operate in controlled airspace. My issue is it must be a PITA to convey that info to ATC each time.

Around here it is pretty easy to avoid the airspace where ADS-B is required, so not much need to explain. What worries me more are the number of pilots flying around out there that think you are not there if you don't show up on the fish finder.

Share this post


Link to post
Share on other sites
5 minutes ago, Tom Baker said:

Around here it is pretty easy to avoid the airspace where ADS-B is required, so not much need to explain. What worries me more are the number of pilots flying around out there that think you are not there if you don't show up on the fish finder.

The duality of technology! Simultaneously increases and decreases situational awareness!

Share this post


Link to post
Share on other sites

If you are near a lot of controlled airspace you will be interrogated and you will see everyone if you have ADSB in. It's when you get away from conjested areas you will have an issue unless someone nearby has ADSB out.

Share this post


Link to post
Share on other sites
3 hours ago, Tom Baker said:

Around here it is pretty easy to avoid the airspace where ADS-B is required, so not much need to explain. What worries me more are the number of pilots flying around out there that think you are not there if you don't show up on the fish finder.

I have seen some stats claiming that close to 90% of planes are equipped with ADSB which means that it is hard not get into habit of more and more relying on ADSB since it works , well,  90% of time ( which is probably already better than radio/visual scanning ) 
 

Share this post


Link to post
Share on other sites

Updated conclusions:

3) You don't need the audio alert in flight but you do need it to perform the quarterly system checks prescribed by ACK. It may also be useful in detecting inadvertent ground activations. I put mine back in, with another new battery, and it seems to be working fine now.

2) This leads me to believe that the battery corrosion I observed did not cause the spontaneous in-flight activation. I now think it was just water in the RJ11 cables. I also think that disconnecting the cable ends, and leaving them off for a week, was critical in allowing the water to eventually dry out.

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
Sign in to follow this  

×
×
  • Create New...