Been looking at various ELTs and their combo pack pricing for new installs. It's hard to get good information about what exactly is involved/required, but I have been reading the installation manual for the Artex ELT-1000. Obviously you've got the unit itself, an antenna, and a remote switch for the panel, GPS data coming in, and a noisemaker. What else?

Antenna- need a dual or single band for the modern 406 Mhz units? I think most can still transmit 121.5 Mhz, so dual band, right?

Antenna cable - Same coax stuff I would use for comm radio, right?

Remote switch - Lots of options it seems, pretty straight forward. They have a light and a switch.

Remote switch interface - Depending on the model ELT you choose, it needs an interface for the remote switch.

Remote switch wire - 22AWG 5-conductor? This is what I have for my electric trim servo.

GPS interface - Some have this built-in, but it can be confusing as the GPS is not actually built-in, the interface to get GPS data from your on-board GPS is what's built-in. It's generally RS-232 serial data in NMEA format. Does this get bundled in with the 15-pin D-Sub somehow?

Buzzer/siren - Is this recommended? The only use for this I can see is for searchers who are within a couple hundred yards trying to find the wreckage. If I survive I'll probably disable it anyway for sanity's sake.

Anything I'm missing? I'm running wire and building mount trays and antenna mounts while the fuselage is bare.

I imagine we should talk internal or external antenna mount position while we're at it. The simple 7" whip is pretty low-profile and seems like it would survive a nose-over onto its back ok, at which point it's in the same position blocked by fabric as if it had been installed internally. On a ride through some trees or brush it might not fare as well. Someone recently told me that 406 Mhz gets through the ferrous fuselage and the fabric okay, but 121.5 Mhz does not. Can anyone confirm that?

Zane,

I'd pick one brand of ELT and design for it. They all have slightly different mountings, wiring, etc. That said, for a mount, you just need a flat spot, solidly mounted to the frame, somewhere logical.

My only experience is with the ACK 406, so be advised.

ACK says that you can mount their antennas inside a fabric or composite fuselage. In fact, Aviat mounts their 406 ELT antennas inside the aft fuselage. That said, the manufacturer suggests that it's up to you to verify that the coatings on the fabric don't interfere with the signals.

Some radio types insist that this type mounting will attenuate the signal. I asked ACK engineer about that, and his response was "How much signal you think you'll get out of a broken antenna stub that's shoved into the dirt?"

The FAA says that the antenna should be mounted within 30 degrees of vertical. I couldn't figure out how to accomplish that in my Cub's aft fuselage, due to lack of mounting.....so I asked that same engineer about the vertical mounting. His response: "Well, exactly how do you plan to crash?" The point being, the antenna is optimized to transmit most efficiently when it's vertical, but what happens if your plane winds up on it's nose? Or upside down? Etc. I suggested to him that I was considering mounting the antenna horizontally in the aft fuselage. He said he saw no problem with this.

But, if I were building, as you are, I'd mount the antenna in vertical orientation, inside the aft fuselage, on a plate that's large enough to provide a satisfactory ground plane. ACK says you can use the fuselage frame for a ground plane on the antenna, but I'd prefer a sheet of metal or some strips of aluminized tapes.

As to the buzzer...the buzzer is intended as a reminder to YOU that the ELT is active, in the event that you don't notice the little red light blinking at you. It's not intended to attract searchers....aint that loud.

The ELT kits are pretty complete. Pick one, go to that company's web site and download their mounting diagram, or call them for it. When you're close to done, order the ELT and hope they haven't changed the mounts....

On the ACK, the NMEA output goes from the ELT to the GPS via a small wire harness. Simple to fabricate, but it takes a bit of a do....mostly to figure out how to build the test device to verify that the ELT is getting the GPS signal.

MTV

When I bought my Artex, it came with everything, including the antenna and the coax. There was enough coax that it could have been mounted a long way from the ELT. The antenna itself is a wire probably a couple feet long and has some sort of choke on it about mid way--it's their "under 200 knots" version. The latest Artex catalog shows a slightly different antenna, but it's still about the same length, I believe.

The only thing it didn't come with was the connecting wire to the panel, and that was 5 wire if I recall. The ELT hadn't been approved for sale yet when I had my IA run that wire, so I contacted Artex to make sure we put in the right stuff. When it finally came out and I ordered it, the only extra thing my IA had to do was to cut an appropriate hole in the panel for the switch--which is a 2 position switch, on and arm--no off position.

At the time, I didn't have a GPS that could be connected (my handheld is a Garmin 96C). When I had the 430W installed a couple years ago, then it was connected to the ELT. I haven't the slightest idea how that was done, as my avionics shop took care of it.

I think the buzzer is part of the TSO approval. Its only purpose is to easily identify the airplane which has an accidentally triggered ELT in a line of airplanes. So far (knock on wood) I've never landed hard enough to set it off. I did briefly turn it on once in my hangar to hear what it sounded like.

Cary

The gps portion is confusing to me. Supposedly, my 396 can be tapped for 3 devices. I have the ACK elt and G4 engine monitor on it right now. It takes a 4 pin mini din. I've heard two different answers on what happens when the gps shuts off. Mine shuts off when the avionics power is turned off. I have to physically turn it on with the switch if I want to run on the internal battery, which causes me some concern if I were to go down and lose power to the gps unit. I'm hoping they've thought of that and there's a few minutes between the interface and real time like satelite radio.

+1 on MTV and Cary's comments.

I've installed 3 of the ACK 406 now and about to put one in our new 182.

For the one I installed in the pacer I did just as Mike was suggesting, vertically mounted antenna inside the aft fuselage on an aluminum plate for a ground plane. It tested well for signal strength and there's one less antenna on the outside of the airplane.

Sam

The ACK I just installed had everything except zip ties. As far as mounting brackets, I installed this the exact same way Northern lights Avionics had installed the Kannad this replaced. Easy, straight forward plug and play. As mentioned in the other thread, the phone wire from the remote switch to the unit is short, so be prepared to have on made up thats a couple ft longer. Granted it worked for my 170, but without any to spare. The manual is simple to understand and interpret, although I have not had time to couple my gps to it yet, so can't speak for that.
I would assume as Mike said, the cheapest easy way to go is pick a unit and go with it. At least you will know that unit is matched for that antenna and that wire and coax, etc.

Nosedragger wrote:The gps portion is confusing to me. Supposedly, my 396 can be tapped for 3 devices. I have the ACK elt and G4 engine monitor on it right now. It takes a 4 pin mini din. I've heard two different answers on what happens when the gps shuts off. Mine shuts off when the avionics power is turned off. I have to physically turn it on with the switch if I want to run on the internal battery, which causes me some concern if I were to go down and lose power to the gps unit. I'm hoping they've thought of that and there's a few minutes between the interface and real time like satelite radio.

The ELT "remembers" the last GPS position it received from the GPS. If the ELT is triggered, it then transmits those coordinates to RCC.

I actually tested that process on my first ACK unit. The activation switch on that one was incredibly sensitive. It triggered in moderate turbulence, descending into OSH. I parked the plane, and shut it down, including shutting down the GPS. I was able to shut down the ELT as well, but it alerted again....bad switch. I got a call from RCC, and out of curiousity, I asked them if they had received a set of GPS coordinates....they gave me my location, within a few meters. That was with the GPS shut off.

If you fire up the GPS on internal power, it will once again transmit an updated position to the ELT, which will "remember" that position, etc..

Oh, yeah, and ACK shipped me a new ELT quickly. They tested the other one, and reported back to me that dropping it from 1/2 inch high onto a desk top set it off......a little too sensitive. The next one was perfect.

Pretty magic stuff.

MTV

mtv wrote:

Nosedragger wrote:The gps portion is confusing to me. Supposedly, my 396 can be tapped for 3 devices. I have the ACK elt and G4 engine monitor on it right now. It takes a 4 pin mini din. I've heard two different answers on what happens when the gps shuts off. Mine shuts off when the avionics power is turned off. I have to physically turn it on with the switch if I want to run on the internal battery, which causes me some concern if I were to go down and lose power to the gps unit. I'm hoping they've thought of that and there's a few minutes between the interface and real time like satelite radio.

The ELT "remembers" the last GPS position it received from the GPS. If the ELT is triggered, it then transmits those coordinates to RCC.

I actually tested that process on my first ACK unit. The activation switch on that one was incredibly sensitive. It triggered in moderate turbulence, descending into OSH. I parked the plane, and shut it down, including shutting down the GPS. I was able to shut down the ELT as well, but it alerted again....bad switch. I got a call from RCC, and out of curiousity, I asked them if they had received a set of GPS coordinates....they gave me my location, within a few meters. That was with the GPS shut off.

If you fire up the GPS on internal power, it will once again transmit an updated position to the ELT, which will "remember" that position, etc..

Oh, yeah, and ACK shipped me a new ELT quickly. They tested the other one, and reported back to me that dropping it from 1/2 inch high onto a desk top set it off......a little too sensitive. The next one was perfect.

Pretty magic stuff.

MTV

Thanks, that's good to know. I've tested mine by pushing the button at 5 minutes after but that's about it.

I think you're supposed to function-check the ELT (in other words, "slam test" it) at annual inspection.

hotrod180 wrote:I think you're supposed to function-check the ELT (in other words, "slam test" it) at annual inspection.

Well, I'm not sure I'd use the term "slam-test" with your mechanic, but, yes, you're right, they're required to be tested annually. No big deal.

MTV

Here you go, no "thinking" required...


FAR 91.207 - Emergency locator transmitters

(a) Except as provided in paragraphs (e) and (f) of this section, no person may operate a U.S.-registered civil airplane unless—

(1) There is attached to the airplane an approved automatic type emergency locator transmitter that is in operable condition for the following operations, except that after June 21, 1995, an emergency locator transmitter that meets the requirements of TSO-C91 may not be used for new installations:

(i) Those operations governed by the supplemental air carrier and commercial operator rules of parts 121 and 125;

(ii) Charter flights governed by the domestic and flag air carrier rules of part 121 of this chapter; and

(iii) Operations governed by part 135 of this chapter; or

(2) For operations other than those specified in paragraph (a)(1) of this section, there must be attached to the airplane an approved personal type or an approved automatic type emergency locator transmitter that is in operable condition, except that after June 21, 1995, an emergency locator transmitter that meets the requirements of TSO-C91 may not be used for new installations.

(b) Each emergency locator transmitter required by paragraph (a) of this section must be attached to the airplane in such a manner that the probability of damage to the transmitter in the event of crash impact is minimized. Fixed and deployable automatic type transmitters must be attached to the airplane as far aft as practicable.

(c) Batteries used in the emergency locator transmitters required by paragraphs (a) and (b) of this section must be replaced (or recharged, if the batteries are rechargeable)—

(1) When the transmitter has been in use for more than 1 cumulative hour; or

(2) When 50 percent of their useful life (or, for rechargeable batteries, 50 percent of their useful life of charge) has expired, as established by the transmitter manufacturer under its approval.

The new expiration date for replacing (or recharging) the battery must be legibly marked on the outside of the transmitter and entered in the aircraft maintenance record. Paragraph (c)(2) of this section does not apply to batteries (such as water-activated batteries) that are essentially unaffected during probable storage intervals.

(d) Each emergency locator transmitter required by paragraph (a) of this section must be inspected within 12 calendar months after the last inspection for—

(1) Proper installation;

(2) Battery corrosion;

(3) Operation of the controls and crash sensor; and

(4) The presence of a sufficient signal radiated from its antenna.

(e) Notwithstanding paragraph (a) of this section, a person may—

(1) Ferry a newly acquired airplane from the place where possession of it was taken to a place where the emergency locator transmitter is to be installed; and

(2) Ferry an airplane with an inoperative emergency locator transmitter from a place where repairs or replacements cannot be made to a place where they can be made.

No person other than required crewmembers may be carried aboard an airplane being ferried under paragraph (e) of this section.

(f) Paragraph (a) of this section does not apply to—

(1) Before January 1, 2004, turbojet-powered aircraft;

(2) Aircraft while engaged in scheduled flights by scheduled air carriers;

(3) Aircraft while engaged in training operations conducted entirely within a 50-nautical mile radius of the airport from which such local flight operations began;

(4) Aircraft while engaged in flight operations incident to design and testing;

(5) New aircraft while engaged in flight operations incident to their manufacture, preparation, and delivery;

(6) Aircraft while engaged in flight operations incident to the aerial application of chemicals and other substances for agricultural purposes;

(7) Aircraft certificated by the Administrator for research and development purposes;

(8) Aircraft while used for showing compliance with regulations, crew training, exhibition, air racing, or market surveys;

(9) Aircraft equipped to carry not more than one person.

(10) An aircraft during any period for which the transmitter has been temporarily removed for inspection, repair, modification, or replacement, subject to the following:

(i) No person may operate the aircraft unless the aircraft records contain an entry which includes the date of initial removal, the make, model, serial number, and reason for removing the transmitter, and a placard located in view of the pilot to show “ELT not installed.”

(ii) No person may operate the aircraft more than 90 days after the ELT is initially removed from the aircraft; and

(11) On and after January 1, 2004, aircraft with a maximum payload capacity of more than 18,000 pounds when used in air transportation.

[Doc. No. 18334, 54 FR 34304, Aug. 18, 1989, as amended by Amdt. 91–242, 59 FR 32057, June 21, 1994; 59 FR 34578, July 6, 1994; Amdt. 91–265, 65 FR 81319, Dec. 22, 2000; 66 FR 16316, Mar. 23, 2001]

I just installed the Ack and interfaced with a 496. Nosedragger, I am wondering what the benefit is of interfacing the G4 with the GPS? I also just got a G3 which is basically the same thing with a smaller display.... It seemed the G3/G4 GPS interface was to display fuel info on a GPS unit, and I didn't think the 396/496 could do that.... But maybe I'm all screwed up!

Selway wrote:I just installed the Ack and interfaced with a 496. Nosedragger, I am wondering what the benefit is of interfacing the G4 with the GPS? I also just got a G3 which is basically the same thing with a smaller display.... It seemed the G3/G4 GPS interface was to display fuel info on a GPS unit, and I didn't think the 396/496 could do that.... But maybe I'm all screwed up!

You should be able to do the same if you desire to track mileage and fuel remaining/range based on groundspeed. Part 135 rules may be different. I seem to remember a little speed bump hooking the ACK to the 396 since it wasn't a certified panel install.

Ok thanks... Makes sense... I'll check it out.

All regulations aside, whom ever you buy it from can hook you up with the components you need. We used Spruce.