ELT Recommendations

[PapuaPilot]

John, where did you find that information for the ACK batteries? I don't see it in the installation manual.

[jrevens]

John, where did you find that information for the ACK batteries? I don't see it in the installation manual.

I took one apart.

[efwd]

LOL, nice John.

[Dave S]

Hey! we are experimenters - that is how we find out how stuff works!

[PapuaPilot]

As a maintenance instructor and an A&P-IA this topic really caught my attention. I have been talking to my co-workers about the subject this morning and I just got off the phone with a tech person at ACK.

Thanks John for the answer about the ACK battery not being airworthy if it was opened. The ACK factory tech agrees - "Don't open the battery, it is sealed unit that is meant to be replaced every 5 years (at the expire date) or if the power/voltage is low".

I need to retract some of what I said earlier and give a better answer about the requirements for 406 ELT inspections. I will specifically address the ACK-04 ELT, but the principles apply to all 406 ELTs.

Every country has its own requirements and I will only address what the FARs require in the USA. If you are in Canada, etc. you need to follow your country's rules for 406 ELTs. Canada has more requirements than the USA does.

The most important thing we need to do is comply with the requirements of FAR 91.207(D) which says:
(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
- This is covered in the ACK manual Section 10
(2) Battery corrosion
- Not covered in the ACK manual. The ACK tech guy said DO NOT open the battery, but you can separate the battery pack from the transmitter section of the ELT and inspect the + and - terminals for corrosion.
- This portion of the FAR is related to the older 121.5 ELTs that had replaceable D cell batteries which had a tendency to leak.
- As a general rule: Only open a battery pack to check for corrosion if your country or the manufacture requires it. This may involve replacing a seal and other parts and varies from brand to brand.
(3) Operation of the controls and crash sensor; and
- This is covered in the ACK manual Sections 9 & 10.
- For other brands follow their instructions for checking the G switch and other controls, including the remote switch.
(4) The presence of a sufficient signal radiated from its antenna.
- This is not covered in the ACK manual. The required self test does not test the signal radiated from the antenna.
- Notice that it talks about the signal from the antenna. This actually is talking about the 121.5mHz signal, not the 406mHz. See below where AC43.13-1B gives you a way to test this with an AM radio, which means you really don't need to take your ELT to an avionics shop or repair station to test this.

The other FAA document that gives us guidance to inspect an ELT is AC43.13-1B, Section 12-22.
12-22. INSPECTION OF ELT. An inspection of the following must be accomplished by a properly certified person or repair station within 12-calendar months after the last inspection:

a. Proper Installation.
(1) Remove all interconnections to the ELT unit and ELT antenna. Visually inspect and confirm proper seating of all connector pins. Special attention should be given to co- axial center conductor pins, which are prone to retracting into the connector housing.
(2) Remove the ELT from the mount and inspect the mounting hardware for proper installation and security.
(3) Reinstall the ELT into its mount and verify the proper direction for crash activation. Reconnect all cables. They should have some slack at each end and should be properly se- cured to the airplane structure for support and protection.

b. Battery Corrosion. Gain access to the ELT battery and inspect. No corrosion should be detectable. Verify the ELT battery is ap- proved and check its expiration date.

c. Operation of the Controls and Crash Sensor. Activate the ELT using an applied force. Consult the ELT manufacturer’s instructions before activation. The direction for mounting and force activation is indicated on the ELT. A TSO-C91 ELT can be activated by using a quick rap with the palm. A TSO-C91a ELT can be activated by using a rapid forward (throwing) motion coupled by a rapid revers- ing action. Verify that the ELT can be activated using a watt meter, the airplane’s VHF radio communications receiver tuned to 121.5 MHz, or other means (see NOTE 1). Insure that the “G” switch has been reset if applicable.

d. For a Sufficient Signal Radiated From its Antenna. Activate the ELT using the ON or ELT TEST switch. A low-quality AM broadcast radio receiver should be used to determine if energy is being transmitted from the antenna. When the antenna of the AM broadcast radio receiver (tuning dial on any setting) is held about 6 inches from the acti- vated ELT antenna, the ELT aural tone will be heard (see NOTE 2 and 3).

e. Verify that All Switches are Properly Labeled and Positioned.

f. Record the Inspection. Record the inspection in the aircraft maintenance records according to 14 CFR part 43, section 43.9. We suggest the following:
I inspected the Make/Model ______________ ELT system in this aircraft according to applicable Aircraft and ELT manufacturer’s instructions and applicable FAA guidance and found that it meets the requirements of sec- tion 91.207(d).
Signed: _______
Certificate No. _______
Date: _______


Notice that the recommended FAA logbook entry says we have inspected the ELT according to:
(1) Aircraft instructions (None - we are the manufacturer, unless it is an S-LSA)
(2) ELT instructions (Of your brand)
(3) Applicable FAA guidance (AC43.13-1B)
(4) The requirements of FAR 91.207(d)
The FAA is saying you must to do all of these things to legally complete an annual inspection on an ELT.

NOTE 1: This is not a measured check; it only indicates that the G-switch is working.

NOTE 2: This is not a measured check; but it does provide confidence that the antenna is radiating with sufficient power to aid search and rescue. The signal may be weak even if it is picked up by an aircraft VHF receiver located at a considerable distance from the radiating ELT. Therefore, this check does not check the integrity of the ELT system or provide the same level of confidence as does the AM radio check.

NOTE 3: Because the ELT radiates on the emergency frequency, the Fed- eral Communications Commission allows these tests only to be conducted within the first five minutes after any hour and is limited in three sweeps of the transmitter audio modulation.

Lastly, follow the manufacture's instructions (ICA) or maintenance manual procedures.
- Follow the ELT manufacturer's instructions for continued airworthiness found in their manual(s). For the ACK-04 you need to do everything listed in Section 10.
- It may have more than the FAA requirements. Do these too.
- It may duplicate what the FAA requires. Don't do it twice.
- It may not include everything the FAA requires. Do what the FAA says too.

[DesertFox4]

Thank you Phil. Good info.

[cubtractor]

This was a great podcast on ELT testing and operation from a representative from SARSAT and The Finer Points podcast.

https://traffic.libsyn.com/secure/tf...a?dest-id=2348

[Dick B in KY]

There is an AD out on the Ameri-King ELT's model AK-450-( ) and AK-451-( ),
2017-16-01 Ameri-King Corporation, effective October 24, 2017. You can download the AD from the web. Quite extensive but since you have to inspect the ELT every year, the compliance is not that hard to do.

Dick B

[Jaguar56]

There is an AD out on the Ameri-King ELT's model AK-450-( ) and AK-451-( ),
2017-16-01 Ameri-King Corporation, effective October 24, 2017. You can download the AD from the web. Quite extensive but since you have to inspect the ELT every year, the compliance is not that hard to do.

Dick B

Where we run in to trouble is the batteries. When they reach the end of their useful life, a TSO replacement is not available as Ameri-King would have to do the TSO and the FAA yanked their TSO capability. So in my case with dead batteries there is really not a legal replacement turning the AK ELT in to a desk ornament.

My plan was to buy some batteries to get it out of the shop and then immediately work on installing the ACK. I would rather have the shop do it, but they are wrapped around the higher testing concept and won’t touch it. I am hoping with some local help I can pull off the install.