ELT's Which one. ?

Tom-D

Tom-D

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Tom-D
Customer wants to up grade to a 406 type.

Which one is the best deal per dollar?

NO PLBs please. this must meet 91.207 requirements
 
Tom-D said:
Customer wants to up grade to a 406 type.

Which one is the best deal per dollar?

NO PLBs please. this must meet 91.207 requirements
Click to expand...
Do they want integrated GPS or no? Do they already have a Waas GPS?

If you get one that does not have integrated GPS (or already have Waas GPS) I agree with @Stewartb.

Otherwise, for more money ARTEX sells them with GPS integrated which brings the search area down significantly.
 
Does your customer, like me, want GPS in the ELT but does not have a source in the aircraft? If so the ELT406GPS at about twice the price looks like the best deal. No 121.5, but I'd like to get rid of that anyway as my current Sharc7 makes the COMs break squelch when flying near a group of FM broadcast transmitters. Hopefully, a 406-only unit will not do that.
 
Mtns2Skies said:
Do they want integrated GPS or no? Do they already have a Waas GPS?

If you get one that does not have integrated GPS (or already have Waas GPS) I agree with @Stewartb.

Otherwise, for more money ARTEX sells them with GPS integrated which brings the search area down significantly.
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When the GPS ELT works like designed. There is no search, just a rescue.

In Idaho the search teams are not even called, the call goes immediately to the local Sheriff or 911 services responsible for the rescue.

Brian
 
My own E-04 gets the GPS source from my G3X. Any modern portable GPS will provide the data to the ELT. The E-04 should cost around $500. If you're replacing the old yellow ACK D cell unit it's really simple since the panel switch and comm cable are already there. The E-04 GPS signal test is really simple to do and ICAs are the best among the ELTs I've seen.
 
Tom, one thing to check is look online how much the batteries cost and how long they are good for whichever ELT your customer decides on.
 
hawk25u said:
Tom, one thing to check is look online how much the batteries cost and how long they are good for whichever ELT your customer decides on.
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I must check to see which he has installed now, then I think we will do a snap in replacement.

He is a new customer I don't know his 182 that well, but tomorrow I'll have a look.
 
Stewartb said:
If you're replacing the old yellow ACK D cell unit it's really simple since the panel switch and comm cable are already there.
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But read the manual carefully. The marketers don't tell you that 406's require a much more rigid mounting than the 121.5 units. It's part of the ELT certifcation requirements. All the 406s I have installed, including the E-04, mentioned the RTCA mounting data: no more than 0.1" deflection when a 100-pound load is applied in any direction. That's a lot stiffer than most existing mounts. Flexible mounts can cause inadvertent actuation, or no actuation at all when it's supposed to. "Crash-hiding vibrations" is the way they word it. If I'm spending a bunch of money on this thing I want it to let the rescuers know I need help.

From the E-04 manual ackavionics.wpengine.com/wp-content/uploads/2018/03/E-04_REV_1.8_SINGLE_PAGE.pdf

...we read:

RTCA document DO-204 paragraph 3.1.8. prescribes the mounting requirements which
must be met when installing this ELT, these requirements are as follows:
The ELT shall be mounted to primary load-carrying structures such as trusses, bulkheads,
longerons, spars, or floor beams. (not aircraft skin) The mounts shall have a maximum
static local deflection no greater than 2.5mm (0.1 inch) when a force of 450 newton's (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.
 
Also does he have a GPS source?

ACK seems good, forgot but I’d want a dual 406/21.5 for sure
 
Dan Thomas said:
But read the manual carefully. The marketers don't tell you that 406's require a much more rigid mounting than the 121.5 units. It's part of the ELT certifcation requirements. All the 406s I have installed, including the E-04, mentioned the RTCA mounting data: no more than 0.1" deflection when a 100-pound load is applied in any direction. That's a lot stiffer than most existing mounts. Flexible mounts can cause inadvertent actuation, or no actuation at all when it's supposed to. "Crash-hiding vibrations" is the way they word it. If I'm spending a bunch of money on this thing I want it to let the rescuers know I need help.

From the E-04 manual ackavionics.wpengine.com/wp-content/uploads/2018/03/E-04_REV_1.8_SINGLE_PAGE.pdf

...we read:

RTCA document DO-204 paragraph 3.1.8. prescribes the mounting requirements which
must be met when installing this ELT, these requirements are as follows:
The ELT shall be mounted to primary load-carrying structures such as trusses, bulkheads,
longerons, spars, or floor beams. (not aircraft skin) The mounts shall have a maximum
static local deflection no greater than 2.5mm (0.1 inch) when a force of 450 newton's (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.
Click to expand...

What was the requirement for 121.5 installations? I recall it being the same.
 
Why would anybody want a 121.5 when a 406 is available. My local CAP commander said they don't even look at 121.5. He said the difference between 121.5 and 406 was days reduced to minutes to locate a rescue.
 
Stewartb said:
What was the requirement for 121.5 installations? I recall it being the same.
Click to expand...
Not based on what the OEMs were using to install their 121.5s. Even the restart Cessnas ('96-on) used a skin-based mount until they started putting in 406s.
 
AKBill said:
.1 inch deformation. That might be hard to measure
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Piece of cake. It's nearly 1/8" inch. A cheap dial indicator will do it, but if a proper mount is designed and used you can push and pull all you like and it won't visibly move. 0.1 is very visible. Don't even need the indicator.

AC43.13-2B gives relevant stuff on such mounts.
 
NordicDave said:
Why would anybody want a 121.5 when a 406 is available. My local CAP commander said they don't even look at 121.5. He said the difference between 121.5 and 406 was days reduced to minutes to locate a rescue.
Click to expand...

If ever. There are no 121.5 satellites in orbit, so only a SAR airplane, or overflying airliner monitoring 121.5, will hear it.

The much higher frequency narrows the location down to a few kilometers, since the Doppler effect that the satellites use is more easily and accurately measurable when the wavelength is shorter. The GPS coordinates are better, but it can take as long as 50 seconds after actuation before the coordinates are sent. Meanwhile, the airplane is burning or sinking, maybe.

Canada requires that a 406 also transmit on 121.5 for final homing, and most ELTs do that. A 406 sends out intermittent signals, while the 121.5 is constant.

The real answer is some automated SPOT-like device that transmits corrdinates every few seconds to satellites, and sends a crash signal. Even if the crash signal doesn't work (fire, sinking, smashing into tiny pieces on impact, or a poorly-mounted ELT tearing loose and ripping free of its antenna cable), the place where the coordinates stopped would be the place to look. But the law would require that it wouldn't depend on the pilot turning it on before flight and off afterward. That's what current ELT regs require.
 
Tom-D said:
When instructions are given, the AC can't be used
Click to expand...

The ELT manual doesn't give instructions on how to build a mount. It just gives the legal requirement and the specification for rigidity. It's up to the mechanic to find acceptable data for making the mounting surface.
 
Dan Thomas said:
The ELT manual doesn't give instructions on how to build a mount. It just gives the legal requirement and the specification for rigidity. It's up to the mechanic to find acceptable data for making the mounting surface.
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But it does tell you how & where to mount it.
OBTW, who would build a mount, when the equipment shelf is for that purpose

We are going with this
http://www.aircraftspruce.com/catalog/avpages/artex11-13989.php
ACK are out of stock and these are about the same price with GPS.
 
NordicDave said:
Why would anybody want a 121.5 when a 406 is available. My local CAP commander said they don't even look at 121.5. He said the difference between 121.5 and 406 was days reduced to minutes to locate a rescue.
Click to expand...

Go set off a 121.5 and see how many aircraft report it.

Up here you’d probably get but a few chirps before ATC started getting pilots reporting it.

Is 406 WITH GPS better, ofcourse, but 121.5 still has use, if I were just flying around populated areas I probably wouldn’t bother with a GPS enabled 406
 
Installation instructions say the ELT must be mounted to structure and that it can't be mounted to skin. Unless the baggage shelf is reinforced structurally it won't meet the 1/10th of an inch of movement at 100# test.

My pro SAR helicopter pilot friends say that if an airliner hears a 121.5 at cruise altitude the search area is tens of thousands of square miles. Unless they have a missing pilot report with a probable path of flight they don't respond to 121.5 reports. Too many false alarms. That's why 406 was developed. Not long ago I accidentally triggered my 406 while working on my plane. About the time I discovered I'd done it the Air Force RCC called to see if I was okay. They knew exactly where I was. Pretty impressive.
 
Stewartb said:
Installation instructions say the ELT must be mounted to structure and that it can't be mounted to skin. Unless the baggage shelf is reinforced structurally
Click to expand...
Equipment shelves are not baggage shelves. They are built for this purpose, and they are certainly not skin.
 
I think that the whole elt requirement is silly at least east of the Mississippi. I am not required to have on my ocean capable sailboat. Why my aircraft? I have one of the units whose pma was yanked. Now I have to spend more money on another government mandated box.
 
Tom-D said:
But it does tell you how & where to mount it.
OBTW, who would build a mount, when the equipment shelf is for that purpose

We are going with this
http://www.aircraftspruce.com/catalog/avpages/artex11-13989.php
ACK are out of stock and these are about the same price with GPS.
Click to expand...

Am I reading it wrong? It says it has a GPS navigation interface, but I don't think I'm reading that it has GPS. The giveaway for me was the lack of a GPS antenna. But I might be wrong.

EDIT: This is in specs:

GPS:
Built-in GPS Navigational Interface (NMEA 0183 or RS 232)

So, that suggests to me that it takes GPS from another source, same as the ACK.
 
Actually, how does that work, with an external GPS source? If you land out pretty, you're liable to have a functioning GPS navigator, but if you crash, I'm guessing getting a functional GPS coordinate from the navigator would be unlikely. I can't see how it would be constantly monitoring the navigator before crash, since that would quickly drain the supposed 6 year battery. Using the navigator for GPS seems sketchy to me, but maybe there's something I'm missing.
 
Huh? A portable Garmin or similar external GPS updates the position to an ACK ELT once per second, or something like that. The ELT will include the most current GPS position with the initial beacon transmission. ACK has instuctions for testing the ELT’s communication with the GPS. Mine works, I know that for sure. Bench tested and field tested! :) If you beacon stays active for 30-40 minutes satellite telemetry will calculate your location. GPS enabling sends it with the first data burst. The former is a wonder of modern technology. The latter improves on it. Enabling a 406 with an external GPS signal has nothing to do with the ELT’s battery.
 
Tom-D said:
But it does tell you how & where to mount it.
OBTW, who would build a mount, when the equipment shelf is for that purpose

We are going with this
http://www.aircraftspruce.com/catalog/avpages/artex11-13989.php
ACK are out of stock and these are about the same price with GPS.
Click to expand...

Dan is correct, the equipment shelves are too flexible. I would bend a channel about 6" across with 1.5" legs (make it wide enough to pick up 5 or so existing rivets on each end) using .070" 2024-T3 and long enough to pick up two bulkheads holding the equipment shelf. Rivet that baby in, 5 or so -4 rivets in each end, it will be like a bridge support.
 
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bnt83 said:
Dan is correct, the equipment shelves are too flexible. I would bend a channel about 6" across with 1.5" legs (make it wide enough to pick up 5 or so existing rivets on each end) using .070" 2024-T3 and long enough to pick up two bulkheads holding the equipment shelf. Rivet that baby in, 5 or so -4 rivets in each end, it will be like a bridge support.
Click to expand...

I've done that, but .040" is thick enough if you bend flanges on the uprights as well. The bottom is wide enough plus a bit for the ELT tray, the verticals about an inch or a bit less, and the flanges at the top about a half inch. They keep the verticals from buckling under downward load. The early part of AC43.13-2B talks about loads and bending, and about testing. You can test that thing by supporting each end on scraps of wood on the floor, put a piece of 2 x 4 representing the ELT on it, and stand on that. A lot stronger and stiffer than it looks or needs to be. If it didnt have the flanges on the verticals, it could buckle.
 
Tom-D said:
Got a reference for that ?
Do you even know what aircraft this ELT will be mounted in ?
Click to expand...

Instead of getting ****y why don't you just fill in the blanks and add a photo or two of your shelf?

My Cessna's ELT was moved from the baggage area skin to the stringers under the baggage floor. It passes the 100# test easily. My Cub's ELT is attached to tubes above the aft baggage. The DAR gave it some pretty good tugs as part of my inspection. It was one of his priorities.
 
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