Check your ELT

[Tom Baker]

I was just reviewing the records on a SLSA with a student who is getting ready for a checkride. Overall the records looked pretty good, except that the aircraft has an Ameri-King AK-450 ELT installed. There was an AD that came out about 2 years ago that requires an inspection every year. This airplane had a condition inspection a year ago next month, and while the required ELT inspection was recorded the compliance with the AD was not. The AD had been out for one year at this point. I bring this up because the Ameri-King was the standard factory installed ELT for many years. If you airplane still has an Ameri-King ELT make sure who ever is doing you inspection to comply with the AD. This also applies to those who have went ELSA if you are doing your own inspection.

[coppercity]

Thanks Tom,

 

Here is a copy of the AD and the ELT manual it references.

 

 

AK450 ELT Manual.pdf ameri_kingAD_2017-16-01.pdf

[sandpiper]

Thanks Tom and Eric,

I also recorded the required inspection but did not know about the AD. I am disappointed that Flight Design does not reference this AD in their section posting "service bulletins for components". They do list the following caveat: 

Please bear in mind that the following tables are not exhaustive references and the appropriate research must be done at the individual component manufacturer’s websites.

So, does that mean that every component part used by FD but not made by FD, including nuts and bolts, must be researched?

Hopefully I am being ridiculous.

[Tom Baker]

For Airworthiness Directives I think you just need to wory about equipmnet that is certified by the FAA. They could also step in and issue one for a SLSA aircraft if the manufacture is being proactive with a safety of flight issue.

[Anticept]

Technically, the FAA can issue an AD against anything. ADs are an amendment to part 39, which is why they have such legal backing. It's just that they don't have an internal procedure for many of the SLSA stuff; you'll probably find the FAA riding the manufacturer or revoking airworthiness certificates before they rally to issue ADs against LSAs.

This is one of the biggest nightmares of the certified world. There can be ADs against individual components and there's no way you would be able to truely know without spending hours upon hours of research. It's a really ineffective system beyond major systems.

Anyways, the ELT thing applies since it's a certified component, as was said.

[Runtoeat]

Interesting that this subject is brought up.  I just did my yearly conditional this month and was checking when I last changed my AmeriKing 450 ELT batteries.  I never really thought much about the ELT, other than knowing the batteries needed to be changed whenever the expiration date showed.  Before going on with other items for the conditional, i recalled there was an AD on the ELT and decided to read this.  Wow!  Clearly wrong on moving on to other things.  This AD clearly states that the AmeriKing ELT must be inspected, verified to be functioning OK and a statement must be put in the log that this has been done.  OK, checking my the log entry for last year's conditional inspection, I see that my mechanic had inspected the ELT and had made a log entry that this had been done.  Per this AD, until this inspection is done (every 12 months) and there has been a log entry made stating that the ELT is functioning OK, the plane is not airworthy.  I also dug out CFR 91.207 and read this, particularly section "c" & "d".  Oops. I was wrong on battery expiration.  My batteries were last changed in November, 2016 and the date on them is "2025".  I figured that I didn't need to change the batteries until 2025 and nothing else was needed for my inspection.  The CFR states that the batteries must be changed at 1 hour cumulative usage or at 1/2 their USEFUL LIFE.  Since there is a 9 year useful life for Duracell batteries,  My take and also my mechanic's take is that 1/2 life is 4.5 years time before the batts expire and must be changed.  My replacement date for the batteries should now be May, 2021.  I'm not airworthy if I don't follow the AD by inspecting the ELT and verifying it functions properly by a log entry.  I am also not airworthy if I don't follow CFR  91.207.  It is noted that the lithium battery in the ELT remote is a 10 life.  The 1/2 life of this battery is then 5 years.  Serious things to consider for something I hadn't given much thought about.  These are interpretations of the rules made by my mechanic and I.  There are forum members who are expert interpreters of the rules. If they have thoughts or comments on this, I'd be interested to hear them.

[Tom Baker]

The inspection per 91.207 must be recorded in the records. The AD while similar requires a little more detailed inspection per the Ameri King manual, and the entry should be as spelled out in the AD. I don't think the half life requirement for the battery applies to the remote.

[Runtoeat]

Tom, to leave no doubt that both the AD and the CFR are complied with, my mechanic records both the AD inspection and the CFR inspection of the ELT in my Aircraft log book.  Thanks.

[MEH]

I disagree with your A&P's 50% life interpretation, and so does Ameri-King. The date printed on Duracell batteries is a shelf life, not a useful life.

Useful life is how long the battery will generate voltage enough to power the device, and it varies with each device, depending on power required.

Read p. 24 Installation and Operation Manual of the AK-450 that is referenced above.  It says "Record the battery replacement date of the new cells being installed using one of the adhesive labels provided with the ELT. The battery replacement date is found on each Duracell MN1300 cell (figure 5). It reads as follows: "Best if installed by (Date)." The date indicated is the date by which the batteries must be replaced" (emphasis mine).

Replace the batteries by the date stamped on them.

The 50% rule that the FAA is referring to is basically saying that if an ELT manufacturer called out a puny battery that would only work for 1.5 hours total, then you can't run the ELT for a cumulative time of 1 hour and still have a valid ELT.  It is "which ever comes first". 1 hour of ELT use, or 50% use of the batteries, not 50% of a batteries' shelf life.

Hope this helps your A&P's confusion. 

[Anticept]

MEH is correct. The 50% life refers to charge, not calender lifespan.

[BravoFoxtrot]

According to the Duracell specifications on the battery they self discharge at a rate of 2-3% per year. At the end of a 10 year period they would have a charge of at least 70%. Changing at the printed date would be still be within the 50% life of the batteries.

[Tom Baker]

I agree that you can legally go to the expiration date on the battery, but personally I changed them more often. I normally replace after 2 years. The batteries are cheap. I have opened up too many ELT's with leaking batteries. Most were within a year or 2 before their expiration date. Also there is a company that repairs ELT's, and their recommendation is replace them every year for the same reason. I just wish I had more things that would run on the used "D" cell batteries.

[Anticept]

3 hours ago, BravoFoxtrot said:

According to the Duracell specifications on the battery they self discharge at a rate of 2-3% per year. At the end of a 10 year period they would have a charge of at least 70%. Changing at the printed date would be still be within the 50% life of the batteries.

This is why they have those printed dates. It is factoring in a number of things including self discharge.

[MEH]

We are all going to have to buy our friends D-cell powered flashlights for Christmas.