121.5 ELT to 406 ELT

jd21476

Line Up and Wait
Joined
Jan 17, 2018
Messages
715
Location
San Diego, CA
Display Name

Display name:
jd21476
I recently bought a NOS Artex 406 ELT that was still with a good battery. I want to swap out my 121.5 ELT becasue some day Id like to fly into Mexico. Is it as simple as unplugging my old one and plugging in my new one? Do the coax and antenna match up? Do I need an avionics shop to do it or just anotate it in my log books?
 
The ELT is a TSO'd system. You'd at a minimum need to swap the antenna to the one required by the unit. Depending on what you are upgrading from/to there would also likely need to be wiring run for the remote switch, etc. Also, this is an alteration, not preventive maintenance, so you'd need someone to sign it off. It doesn't need to be an avionics shop however.
 
The ELT is a TSO'd system. You'd at a minimum need to swap the antenna to the one required by the unit. Depending on what you are upgrading from/to there would also likely need to be wiring run for the remote switch, etc. Also, this is an alteration, not preventive maintenance, so you'd need someone to sign it off. It doesn't need to be an avionics shop however.
Thank you
 
More than that. To be legal, it has to be installed in accordance with the relevant installation manual, and there are requirements that the old 121.5 ELTs did not have to meet. For instance, the ELT has to be mounted to primary structure, not the skin as was common with the old units, so a custom bracket has to be designed and made and installed. Without that, the ELT may not activate. The mount has to be able to withstand a 100 pound force in any direction with no more that 0.1" deflection. The antenna mount has to withstand a 20 pound force. A remote switch/warning light must be installed. A buzzer must be installed near the ELT.

I have found numerous 406s way outside the requirements. Beats me why an owner would pay nearly a thousand bucks for one, then cheap out on the installation so it has little chance of working when it's needed.
 
More than that. To be legal, it has to be installed in accordance with the relevant installation manual, and there are requirements that the old 121.5 ELTs did not have to meet. For instance, the ELT has to be mounted to primary structure, not the skin as was common with the old units, so a custom bracket has to be designed and made and installed. Without that, the ELT may not activate. The mount has to be able to withstand a 100 pound force in any direction with no more that 0.1" deflection. The antenna mount has to withstand a 20 pound force. A remote switch/warning light must be installed. A buzzer must be installed near the ELT.

I have found numerous 406s way outside the requirements. Beats me why an owner would pay nearly a thousand bucks for one, then cheap out on the installation so it has little chance of working when it's needed.
Yup, yup and yup.
My old 121.5 elt didn't work during annual.
I had my avionic shop install a 406. It was all different just like Dan described.
My avionics shop had do a test and get a print out. Then it was registered with Nora in my name. I have to cancel that when I sell the plane.
It can only be tested a limited amount times also before the 6 year battery has to be replaced.
IMG_2079.JPG

Been there about 2 years now with no problems. Shortly after I got it someone's elt was going off at my airport, I thought it might be me. I called the phone number and someone answered and looked it up confirmed it was not mine.
IMG_2080.JPG

I got a activation/test switch on the panel that I didn't have before.IMG_4137.jpeg
 
Last edited:
Beats me why an owner would pay nearly a thousand bucks for one, then cheap out on the installation so it has little chance of working when it's needed.
After I got my plane, the very first order of business was a trip to a bona fide avionics shop for a new comm, ADS-B transponder, and a 406 ELT. Imagine my surprise when I learned, after the fact (probably from here) that they should not have mounted the new ELT where the old one was...
 
The Installation Manual for the ME406 ELT. It might be the one the OP has, or it might be another Artex 406.
https://www.peter2000.co.uk/aviation/kannad-elt/artex-me406-570-1600_Manual.pdf

Note that the earlier version of this ELT had the Velcro strap retaining it in the mount. These straps failed in some crashes, and the ELT can then fly around and rip off its antenna cable. So no signal. Artex started using stainless steel straps, with a latch.

A relevant excerpt from that manual:

1710459680589.png
 
Back
Top