406MHz ELT with GPS

airheadpenguin

Pre-takeoff checklist
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airheadpenguin
Its battery replacement time in our 121MHz ELT, and while a replacement ELT is close to 2000% more expensive than a battery if we don't do this now it won't be done for at least 2 more years.

I'm looking at the Kannad, Sky Hunter and Emerging Lifesaving Technologies units that 'Spruce carries.

Anyone out there with experience in these units?
 
Its battery replacement time in our 121MHz ELT, and while a replacement ELT is close to 2000% more expensive than a battery if we don't do this now it won't be done for at least 2 more years.

I'm looking at the Kannad, Sky Hunter and Emerging Lifesaving Technologies units that 'Spruce carries.

Anyone out there with experience in these units?

Most companies have replacement units that use the same tray and remote switch as the unit being replaced. Basically the install is simple...change the unit out, plug in the remote switch, change the antenna (usually with the same coax) and done. Both Ameriking and ACK have replacements around 650-700 give or take.
 
Internal GPS in 406 ELTs is an evolving feature. Make sure to read up on the units and see whether they need an additional GPS antenna, additional ship's power, etc. Not all units are equal in that respect and the installation details may lead you to favor one or another. Most guys I know who've added GPS to their beacons use the ACK and take the signal from their regular GPS. Even handhelds have data output and if you're like most guys and have it installed in AirGizmo dock the wiring is pretty simple. As for re-using the old tray? I'd wager at least 75% of ELT installations don't meet installation requirements. Review yours and decide whether it needs to be corrected. Attaching to the aircraft skin isn't allowed. It has to attach to structure. Maximum allowable deflection of an installed ELT is 1/10th of an inch using 100# of pull in the most flexible direction.
 
I'd wager at least 75% of ELT installations don't meet installation requirements. Review yours and decide whether it needs to be corrected. Attaching to the aircraft skin isn't allowed. It has to attach to structure. Maximum allowable deflection of an installed ELT is 1/10th of an inch using 100# of pull in the most flexible direction.

For sure. I've been finding too many installed 406's that don't meet the RTCA rigidity requirements. It's as if the installers aren't reading the manual. The old 121 mounts don't come anywhere near the new standard.

Units with GPS built in aren't going to start looking for satellites and establishing a position until the airplane crashes. If that GPS antenna is in the dirt, or the airplane is sinking, or on fire, it never will get the coordinates. A unit that takes the GPS stream from nav radios would be better but the install costs a bunch more.

Dan
 
My two old ACK E-01 121.5 units had the same installation requirements. Neither met the standard until I switched to Artex 406 units and the mechanic at the time mounted them correctly. RTCA DO-183 was issued n 1983. I've never been able to find out if the ELT mounting requirements have been amended over the years but I know the current standard applied/applies to 121.5s as well. I'm surprised how some mechanics overlook poor installations.

RTCA Document DO-183i paragraph 3.1.8 describes the mounting requirements which must be followed when choosing a location on which to mount an ELT. It reads as follows:
THE ELT SHALL BE MOUNTED TO PRIMARY AIRCRAFT LOAD CARRYING STRUCTURES SUCH AS TRUSSES, BULKHEADS, LONGERONS, SPARS, OR FLOOR BEAMS (NOT AIRCRAFT SKIN). THE MOUNTS SHALL HAVE A MINIMUM STATIC LOCAL DEFLECTION NO GREATER THAN 2.5mm (0.1 INCH) WHEN A FORCE OF 450 NEWTONS (100 lbs) IS APPLIED TO THE MOUNT IN THE MOST FLEXIBLE DIRECTION. DEFLECTION MEASUREMENTS SHALL BE MADE WITH REFERENCE TO ANOTHER PART OF THE AIRFRAME NOT LESS THAN 0.3 METER (1 FOOT) NOR MORE THAN 1.0 METER (3 FEET) FROM THE MOUNTING LOCATION.
 
If you're really worried you'll be better off getting a SPOT or Spider Tracks, even if the plane sinks or burns up, get to safety and hit the button.
 
If you're really worried you'll be better off getting a SPOT or Spider Tracks, even if the plane sinks or burns up, get to safety and hit the button.

I think that eventually that technology will become the official ELT technology. It would be much easier to find an airplane that left an electronic trail rather than one that destroyed or incapacitated its ELT when it crashed. ELTs only work as intended in about 50% of accidents.
 
I bought and had installed one of the 406 ELTs with GPS in my Cherokee 180 from Emerging Lifesaving Technologies. The all in one fin antenna is pretty cool too :)
 
When I finally get around to buying my own plane, the first upgrade that I plan on doing if it has not already been done is to install a 406 w/ GPS. It just makes good sense in my mind.
 
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