ACK 406/121.5 MHz E-04 ELT

From $499.00 to $522.00
Part Number:

  • Overview
    The E-04 ELT is a direct replacement for the more than 62,000 model E-01 ELT's (by ACK) on the market today. The E-04 fits directly into the current E-01 mounting trays and uses the same remote control panel indicator. The E-04 external antenna will utilize your current antenna mounting and wiring installations.

    Note: The installation manual for this item requires the installation of 2 very specific batteries for operation - Duracell part number PX28L or Eveready part number A55 (or equivalent) for installation into the switch assembly and Duracell part number CR2 or equivalent for installation into the audio alert indicator.

    Retrofit Kit does not include remote

    Warranty: All warranty issues must be handled directly with the manufacturer. These are non-returnable and non-refundable once installed. If any attempts have been made to install this unit it becomes a warranty issue and can only be resolved through the manufacturer directly.
    There is a $250 Recertification fee in addition to the 15% restock fee on all ACK products that have been opened.
  • Features
    • Accepts GPS position input data from Bendix/King. Garmin, Nema 0183 GPS
    • Antenna is swept back 20 degrees, and features a molded plastic base.
    • 5 watts @ 406MHz for 24 hours, and 100 Mw @ 121.5 MHz for 48 hours.
    • Simple plug in audible alert indicator.
    • Lithium battery pack offers a 5 year battery life, and makes it substantially lighter.
  • Specifications
    • 7.75" long
    • 2.85" width
    • 2.85" height
    • 1.6 pounds in weight with battery
    • Remote requires a Duracell PX28L 6 volt lithium battery or an Eveready AS44 battery
    • Audible Alert Indicator requires a Duracell CR2 3 volt lithium battery or equivalent
  • Documents
  • In The Box
    New Install Version
    • E-04 121.5/406 MHz ELT
    • E-04.5 Remote with horizontal placard
    • E-04.12.2 Remote vertical placard
    • E-04.8 Whip antenna
    • E- Electrostatic discharger
    • E-04.10.4 Coax cable 60"
    • E-04.7 Audio alert
    • E-04.4 Mounting Tray
    • E-04.4.1 Retaining strap front
    • E-04.4.2 Retaining strap battery case
    • E-04.10.6 Female 4 pin DIN plug
    • E-04.10.5 15 foot remote cable
    • E-04.10.3 Audio alert cable
    • E-04.11.1 Switch cover
    • E-04M Installation/Operation/Manual
    Retrofit Kit Version
    • 121.5/406 MHz ELT
    • Remote horizontal placard
    • Remote vertical placard
    • Whip Antenna
    • Electrostatic Discharger
    • Audio Alert
    • Female 4 Pin Din Plug
    • Audio alert cable
    • Switch cover
    • Installation / Operation Manual
  • Accessories

    Enter the quantity desired of each item in the Buy column.

    Description Part Number Price Buy
    ACK E-04 REPLACEMENT BATTERY 11-10012 $166.75
    ACK E04.4 MOUNTING TRAY 11-13526 $21.85

  • Reviews

    Write a review

    by Jacob B

    I installed an E-04 replacing the old E-01. It could not be more simple. A new battery into the panel switch, replace the main unit and plug in the speaker, and remove and install the new antennae, and your done. Whole thing took two hours at the most. The quality is reasonable. The price is very realistic, these guys aren't gouging you.

    by William M

    I installed one of these units on my plane 4 years ago. Yesterday a student accidentally pushed the transmit button on the sub panel. *while the plane was still in the metal hanger*.
    I got a call from the air force wanting to know if everything was OK.!!!

    If you need an ELT... this is the one to get.

    by Dayton F

    I installed an E04 two years ago with a full pannel upgrade. It is on its 3rd battery--they're VERY expensive, must be shipped by ground, haven't been stocked East of the Mississippi and there is no way to check its (battery's) status untill it is known dead. Also cannot check the 406MHz signal data content at the 3 Avionics shops which have changed the battery!

    by Mike A

    One of our distributors ask me to respond to the comments by the Dayton Flight Department. We have never been contacted by anyone from this company and cannot find any listing on the internet. To date we have delivered over 9300 E-04 ELT's. We have had no battery issues other than when people inspect the ELT and place the red cap over the switch without reading the manual and inadvertently turn it on without an antenna. The later model ELT's have a warning sticker by the switch.

    They may be confusing us with a similar looking competitors ELT that has been having issues with battery life.

    ACK Technologies Inc

    by Stanford S

    An ACK, Model E-04 saved my father, and my life on September 9th, 2012. For ultimate survival, we also recommend an additional hand-held McMurdo 406 MHZ, PLB.

    Google Search: Power Loss Over Rough Seas


    by Ken G

    Before installing be sure to have a CR2 3-volt and a Duracell PX-28L 6 volt battery on hand. It won't work without them and are not included in the kit. I would like to have a few words with the designer(s) who couldn't figure out how to make a system that doesn't need additional batteries, and requires two types of different voltages at that. The need for batteries is bad enough, but how about at least a common battery such as AA or AAA?

    by Forrest M

    This was a very easy installation. The tray mounted right where I removed my old ELT and tray, and there was plenty of cable to make it to the front for the remote switch. You do need to purchase two small batterys, one for the remote switch, and one for the audio alert indicator,about $20 extra, they are good for 10yrs though before replacement.
    I'm quite happy with my decision to use this ELT.

    by Dayton F

    Responding to Mike Akatiff's assertion there are no battery problems: The Installer might have wired the unit incorrectly to cause battery drain, but it SURELY was not on otherwise the CAP or NOAA would have notified me. Radio shop tests confirm there is power radiating from the antenna when on, and it stops when off is selected. Perhaps it is a defective unit--I shall contact ACK and discuss a warranty replacement. I have rated it 3-stars because I don't have enough data to rate it 1-star. I have just ordered my 5th replacement battery!!! Louis Leet / Dayton Flight Dept

    by Dayton F

    ACK requested that I send them the ELT I mentioned before was eating batteries. I don't know why I didn't do just that a couple years earlier... Their Repair Department found a defective Circuit Board in the unit, replaced it and re-certified the unit as Airworthy (8130-3). Kudos to Mike Akatif and his team for great customer support and a rugged product. Thanks! Lou Leet

    by E. S

    The two additional and different battery design for the buzzer/switch panel really is DUMB! Why not use the aircraft power in place of them? If necessary, optically-couple the LED/buzzer outputs for electrical isolation of the ELT from the aircraft power. The outputs ARE anciliary to the ELT's primary function.

    The remote and GPS cables are not properly stress-relieved against flex-induced failures at the ELT body exit.

    If ACK used standard 8-pin RJ-45 (LAN) modular plugs for the remote connection, COTS boots could be used for the strain-relief on the cable ends, and you'd have a growth path (existing conductors for backwards compatibility) for any future new functionality. You could also use SHIELDED cables, for RFI rejection, too.

    I agree with the need for mechanical protection of the unit's BNC antenna connector (the ACK approach is sound), but it can be hard to get at/connect, once you've installed the ELT in the aircraft.

    by Maarten V

    I installed an E-04 ELT in my homebuild Zenith 601 XLB and it really saved my butt. Installation was simple went smoothly and I connected the ELT to one of the serial outputs of my Dynon EFIS as the GPS location source. All worked the first time.
    On a nice Monday afternoon I took of from work and went flying. During takeoff from the remote third airport (49R) my canopy popped open while climbing through 100 feet and even though I dove back to the runway ahead I was unable to regain control and the the airplane crashed two thirds down the runway, upon impact I broke my back. when I regained my conscience I could only push myself out of the cockpit onto the wing but I could not move myself any further. Unknown to me, and even though my airplane was totaled, my ELT had done it's work and warned the center in Colorado with my airplane ID and my location. Based on my submitted call list they first called my home, but my wife was out working, then they called my wife's cellphone which she didn't answer since she was working. Finally they reached my daughter and inquired whether the signal they received from the small airport was a likely valid distress signal, my daughter confirmed this, but they stated they would wait for one more signal from the ELT before contacting search and rescue. My daughter, didn't like this delay and immediately contacted the local sheriff who arrived about twenty minutes after the crash at the airport together with a local ambulance. The 406 MHz system is really great, with the added knowledge of the plane involved, the location of the accident and the database with contact numbers chances for a quick rescue have increased tremendously. I could easily have spend the night on the runway since traffic is very light at this airport, but now I was airlifted back to a hospital in San Antonio with very little delay and am currently almost completely recovered from the accident.

    by Mike C

    Nice unit. Easy to install. Replacement battery cost is outrageous! $130.00!!!

    by Greg G

    Long Cables that come with the unit are junk we have 3 of these in our fleet and 2 of the long cables failed out of the box unfortunately we had already installed the cables and reassembled the aircraft ( my Bad ) but still remote cables are junk be sure to bench check everything prior to install

    by Airplane G

    This is one of the easiest ELT installs and best ELTs as far as durability goes. This is the best bang for the buck. And I would also like to add that these batteries are cheap as far as pricing, if you think $130-$160 is outrageous or ridiculous then you need to sell your airplane and get out of aviation all together.

    by Jeff

    First off, had I known this unit requires three separate batteries, all of which are oddball part#s I would have never purchased in the first place. Also the harness supplied for the remote panel switch is NOT aircraft quality. I cannot see how this unit ever got certified.

    Less than 3 years after new install this unit is completely dead. Lets hope my A&P can find a cheap fix. My original ELT was 20+ years old was still working when I put this ACK unit in. Should have left well enough alone.

    by Mike H

    Easy install just did two in the last week. Mooney M-20J no issue. Piper Navajo, removed an ELT-10 & the tray screwed into the existing holes.

    by Verle B

    Arrived in new condition. Have not installed yet.

    by Cris A

    I was worried the supplied cable for the remote would be too short for my Cardinal, but it was fine, by a foot. Install was quick and holes were accurate for the ELT, placing the remote head was a bit rougher, but not hard. If you gotta have an ELT (and you do), this is an easy install or upgrade.

    by Rams A

  • Q+A

    Ask a question

    What is the difference between the USA and international version?
    If you have a USA registered aircraft you will need a USA version (programmed for the USA). If you have an aircraft registered outside the USA you will need the international version in which we will need to know the country of registration so we can specifically program. You can fly any where in the world the key is programming to the country of aircraft registration.

    What is the difference between complete (new install) and retrofit kit?
    If you have an ACK E-01 that you are replacing you can save some money and buy the retrofit kit as you already have parts installed that the E-04 will use. If you do not have an E-01 then you will need to buy the complete kit which will be a new installation.

    Does the ACK E-04 ELT transmit your GPS coordinates as well as 406?
    By it self, no you will have to connect the E-04 to an external GPS to gain this feature. Refer to the manual for how to connect.

    How does an AP/AI test the unit at the annual condition inspection for proper function? Are there any special tools/equipment needed to test?
    All of this is stated in the E-04 manual but a unit self test and checking lines for any corrosion is about all you need to do. No tools are needed and cost will only be the time to do the self test and check the lines.

    I'm interested in the ACK E-04 to replace a Narco 901 ELT, so I need the full installation kit. What else do I need in terms of panel indicators, etc. that are not in the package. Are there other required parts/special wire to connect to my Garmin panel GPS (530W)?
    The E-04 is complete 11-06395 (For USA registered aircraft) for a new installation. For GPS connection you will need to refer to section 6 of the manual (on the Document Tab) which tells you what wire you will need based on your installation.

    On page 6, immediately above Figure 9, there is the statement ...to connect the ELT RS 232 data and power to the aircraft systems. Is the ELT to be connected to Aircraft Power? I thought their power was independent from the aircraft.
    In most cases yes the ELT is independent of aircraft power unless the manual state so and in this case is require if you add GPS information to the ELT.

    Does this ELT meet the requirements for the 406 required for Bahamas travel? With a new installation kit, is it approved for installation in the PA28-180?
    The Ack 406/121.5 MHz E-04 ELT will meet the future Bahamas 406 Mhz Requirement and is approved for installation in a PA28-180.

    What is the battery replacement item for the ACK 406 E-04 ELT?
    The replacement battery for the ACK 406 E-04 is part# 11-10012.

    What is included for a new installation?
    The ACK 406/121.5 MHZ E-04 ELT comes with the ELT, Antenna, Remote Switch, Alert Buzzer and wiring.

    Is a whip antenna available for the AKC-406/121?
    Yes, the Whip antenna for the ACK 406/121.5 MHZ ELT is P/N 11-10465.

    Does the new install version of the ACK 406/121.5 E-04 ELT include a mounting tray?
    The new install version of the ACK 406/121.5 E-04 ELT includes a mounting tray.

    Is this ELT approved for installation in a 1952 Cessna 170B?
    All ELT's are TSO'd but do not have an STC for any specific aircraft. Per the manufacturer, a log book entry is all that is required for installation.

    Does the new install kit for the ACK 406/121.5 MHZ E-04 ELT include the cables to connect the remote control panel indicator and the audio alert?
    This wire is not included. Instructions on wiring are documented in the instruction manual.

    Which Programming type is required for operating an N Registered aircraft in Europe. Is it the USA version or the International version? Can it be supplied with 8130 Form?
    If you have a USA registered aircraft you will need a USA version (programmed for the USA). You can still purchase an 8130 form. Please indicate request at time of order.

    There is only a $10 savings to buy the Ack 406/121.5 Mhz E-04 ELT retro-kit. What comes with each kit?
    The retrokit comes with the transmitter, lithium battery, external antenna, plug in audio alert and install manual. The new install kit comes with the transmitter, lithium battery, external antenna, remote control, audio alert, mounting tray, retaining straps, remote cable, coax cable and install manual.

    Is the remote switch & cable included in the Retrofit Kit?
    No, the retrofit kit (11-06396) does not include the remote switch and cable. It only includes the ELT with battery, an external antenna, plug in audio alert, and install manual.

    Composite aircraft, can the antenna be mounted inside the fiberglass cabin? and still get signal to the satellite?
    Yes, as long as no metal is surrounding the antenna it can be mounted inside the fuselage.

    Does the ACK 406/121.5 MHz E-04 ELT new install kit (part # 11-06395) come with a mounting tray?
    Yes, the ACK 406/121.5 MHz E-04 ELT new install kit does include the mounting tray. Here are the list of contents in the kit:
    • E-04 121.5/406 MHz ELT
    • E-04.5 Remote with horizontal placard
    • E-04.12.2 Remote vertical placard
    • E-04.8 Whip antenna
    • E- Electrostatic discharger
    • E-04.10.4 Coax cable 60"
    • E-04.7 Audio alert
    • E-04.4 Mounting Tray
    • E-04.4.1 Retaining strap front
    • E-04.4.2 Retaining strap battery case
    • E-04.10.6 Female 4 pin DIN plug
    • E-04.10.5 15 foot remote cable
    • E-04.10.3 Audio alert cable
    • E-04.11.1 Switch cover
    • E-04M Installation/Operation/Manual

    What comes with the ACK-04 ELT, part number 11-06395?
    Yes, the ACK 406/121.5 MHz E-04 ELT new install kit does include the mounting tray. Here are the list of contents in the kit:
    • E-04 121.5/406 MHz ELT
    • E-04.5 Remote with horizontal placard
    • E-04.12.2 Remote vertical placard
    • E-04.8 Whip antenna
    • E- Electrostatic discharger
    • E-04.10.4 Coax cable 60"
    • E-04.7 Audio alert
    • E-04.4 Mounting Tray
    • E-04.4.1 Retaining strap front
    • E-04.4.2 Retaining strap battery case
    • E-04.10.6 Female 4 pin DIN plug
    • E-04.10.5 15 foot remote cable
    • E-04.10.3 Audio alert cable
    • E-04.11.1 Switch cover
    • E-04M Installation/Operation/Manual

    Do your ELTs ACK 406 EO4 come tested and certified to be installed in an aircraft or do I have to send it to a radio shop before my AME can install it?
    Yes, the E-04 comes tested and certified for installation.

    Does the ACK 406/121.5 MHz E-04 ELT come with the battery, or should that be ordered separately?
    Yes, the battery is included.

    Can the ACK E-04 be installed in an airplane without electrical system?
    The E-04 can absolutely be installed in an aircraft with no electrical system. It runs on stand alone power from it's own battery pack. The E-04 only requires 10-30 VDC ship power to properly operate if you hook up the GPS and that is an optional feature.

    What are the physical dimensions of the ACK E-04 ELT?
    7.75" long x 2.85" width x 2.85" height. 1.6 pounds in weight with battery.

    Is the ACK 406/121.5 MHz E-04 ELT FAA TSO Approved?
    Yes, this ELT is FAA TSO approved for use in certificated aircraft.

    Can I replace an old AK-451 with the E-04 using the old installation?
    No, you would need to do a complete new install.

    I am in the process of an aircraft restoration which wont be complete for sometime, however, would like to purchase and install an ELT before the interior install. Can I do the registration and other information at a later date?
    For U.S. aircraft, all registration can be done at anytime prior to installation. For international aircraft, the unit must be programmed at time of purchase.

    Im building a composite/fiberglass aircraft and I see from the other question that the antenna can be mounted inside the fuselage provided there are no other metal parts nearby. Does the antenna need a groundplane? And if so how large?
    If the antenna is being mounted on a non conductive portion of the airframe, a supplementary ground plane must be installed. The supplemental ground plane must have a minimum diameter of 24", however 48" will provide maximum power at 121.5 MHz and is recommended. The ground plane must be centered around the base of the antenna. This may be fabricated out of copper, or aluminum tape. Full details of the ground plane requirements are available on Pages 3-4 of the installation manual under the "Documents" tab.
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