Tail NAV Light Electrical Issue: One Step Forward, Two Steps Back

[Johnny U]

On 4/25/2021 at 3:07 PM, N201MKTurbo said:

I may have some pieces of 18 ga wire, with that pin crimped on it left over from my avionics upgrade. I will be out at the hangar  tomorrow, I will check. If I do I will send it to you and you can splice the wire down stream of the connector.

I might take you up on this depending on how it goes with the Deutsch style crimper...

[N201MKTurbo]

15 minutes ago, Johnny U said:

I might take you up on this depending on how it goes with the Deutsch style crimper...

The wire I have is a girl, you need a boy.

A guy at work has the extractor for these. I will take the plug in and pull a wire out tomorrow.

[Johnny U]

On 4/25/2021 at 5:42 AM, TomM20F said:

Advisory Circular AC No: 43.13-1B ACCEPTABLE METHODS, TECHNIQUES, AND PRACTICES - AIRCRAFT INSPECTION AND REPAIR is the reference I would use for your legal question. A&P will want some reference to substantiate the repair. I think you will be able to extract the old pin, install new and repair the connector. I also think you could abandon the pin, leave the connector in place for the remaining wires and bypass for your broken wire. Use 2 aviation butt splices, a piece of aviation electrical wire of same AWG  and an aviation connector. Same result, same functionality, approved components at the same location. As long as A&P approves of repair it seems this would be easier and you won't break the rest of the wires in the process.

Hi Tom- For posterity I am liking the to the FAA's PDF version of the circular https://www.faa.gov/documentLibrary/media/Advisory_Circular/AC_43.13-1B_w-chg1.pdf . Electrical starts in Chapter 11 on page 11-1 (the 492nd page of the PDF). @A64Pilotmentions Ancor and I bought those for the terminal connections, but I had previously bought these butt splices from Amazon. From the AC (11-167 paragraph b):

b. Many types of aircraft splice connectors are available for use when splicing individual wires. Use of a self-insulated splice connector is preferred; however, a non-insulated splice connector may be used provided the splice is covered with plastic sleeving that is secured at both ends. Environmentally sealed splices, that conform to MIL-T-7928, provide a reliable means of splicing in SWAMP areas. However, a non-insulated splice connector may be used, provided the splice is covered with dual wall shrink sleeving of a suitable material.

It seems like the last sentence allows flexibility to use non-milspec connectors if they are dual-wall shrinking. Since this is mentioned explicitly in the description of the Amazon item linked to above, I think we are all set on that.

 

[Johnny U]

1 hour ago, N201MKTurbo said:

The wire I have is a girl, you need a boy.

A guy at work has the extractor for these. I will take the plug in and pull a wire out tomorrow.

Thanks Rich!

[EricJ]

13 hours ago, Johnny U said:

It seems like the last sentence allows flexibility to use non-milspec connectors if they are dual-wall shrinking. Since this is mentioned explicitly in the description of the Amazon item linked to above, I think we are all set on that.

It is not a requirement to use milspec splice connectors or end terminals.   Many people use the plain vinyl insulated crimp connectors for splices and terminals that look like these:

https://www.amazon.com/Flytuo-10-22AWG-Connectors-Insulated-Electrical/dp/B08NFSBN1J

The main thing is to use the proper ratcheting crimper, like what is described in AC 43.13 Par 11-178, like these:

https://www.amazon.com/Crimping-Tool-Insulated-Electrical-Connectors/dp/B07GFLWKTT/

There are similar ones with swappable jaws that allow crimping a lot of other stuff, too, like coax connectors, etc.

As you mention, for SWAMP areas or if other requirements drive, then there are plenty of alternatives.   The ancor terminals with heat shrink are nice, but may be overkill for some things, and require application of a heat gun for the heat shrink.

 

[A64Pilot]

Be careful with Amazon butt spice connectors, I’ve gotten some that the crimp barrel was shorter than Ancor and was soft aluminum, which doesn’t retain the wire as well.

‘Ancor barrels are longer and made of tin plated copper

Edited April 30, 2021 by A64Pilot

[Johnny U]

So an update on the resolution for this- the Deutsch-style crimper that we bought worked well on the Amp II pin connectors. The one issue was the pin depth holder made it such that after crimping when you pulled it back out, the barbs on the AMP II caught (and did their job) and got the pin stuck in the tool. By unscrewing and removing the pin holder- and holding the depth of the pin in the crimper by hand- this issue was resolved. Perhaps a more delicate and precise pin removal after crimping would have avoided this issue in the first place, but at $3 a pop we just removed the depth holder. Either way the crimps were tight and there was no slippage of the wire/pin assembly.

In the end we ended up replacing the pin that came loose for the battery relay in order to get power back on and then the other one for the original problem with the NAV light tail circuit. Our A&P took a look before we buttoned it back up and we are now signed off and flying with a new Whelen LED tail strobe/NAV.

Thanks to all who helped us figure this out!

 

[carusoam]

Great follow-up Johnny!

Thanks for sharing the detailed details.

Best regards,

-a-