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almost engine fire video - electrical question

jcarne

Well Known Member
Patron
Hello, Mike Patey (guy who built Turbulence and Draco) recently posted a video of a Piper Arrow (I think) that almost caught fire due to some kind of electrical short. He did not elaborate on what wire it was but it sounds like it was a rather large one firewall forward. Video here. In the end he had to cut the wire to prevent further damage and most likely a loss of the airplane.

So my question, would an ANL fuse probably have prevented much of the carnage? I understand an ANL takes significantly more current than their rating to blow but this sure seems like one of them cases based on his description. I am curious about this because it also seems to be standard practice to run larger feeders un protected. (although I personally did not do that on my build)

Anyways, I wanted to get a more expert opinion on this situation as I'm no electrical wizard.
 
Can't do it

Between the battery and master contactor, and between the battery and the starter solenoid, you can't really put a fuse or an ANL in-line. They need hundreds of amps to start (for a very short while).

If you put something big enough to handle the starter current, you could still get a short that would melt the insulation.
 
Between the battery and master contactor, and between the battery and the starter solenoid, you can't really put a fuse or an ANL in-line. They need hundreds of amps to start (for a very short while).

If you put something big enough to handle the starter current, you could still get a short that would melt the insulation.

I see what your saying but based on the flame/smoldering wires also being in the panel area of the aircraft it seems to me that it was after the starter and contactor. Kind of hard to tell based on the information I suppose. If it is after the starter/contactor connection it seems an ANL would have blown well before this amount of damage was done.
 
Useless YouTube blather. Not enough information, and there is no telling what someone may have done to old Cherokee. Ignore it. Build to plans, install wiring per Vans or Nuckols.
 
Useless YouTube blather. Not enough information, and there is no telling what someone may have done to old Cherokee. Ignore it. Build to plans, install wiring per Vans or Nuckols.

Not looking to change the way things are done. Just looking to those more electron gifted than I to maybe showcase what could have caused something like this and what could have prevented it. Nothing more...

I do agree that there is quite a lack of info to go on though. I'm not one to speculate but thought maybe someone out there has seen this before. Just trying to learn. If there isn't enough info in the pros opinion to elaborate, I'll move on.
 
Not looking to change the way things are done. Just looking to those more electron gifted than I to maybe showcase what could have caused something like this and what could have prevented it. Nothing more...

I do agree that there is quite a lack of info to go on though. I'm not one to speculate but thought maybe someone out there has seen this before. Just trying to learn. If there isn't enough info in the pros opinion to elaborate, I'll move on.

I saw the same video since I subscribed to his channel. Of all the things I don't know about building airplane, electrical system is probably the worse of my unkowns. It's hard to think a certified airplane that has to be annual will have electrical modifications that resulted in this serious electrical fire. While building to plan works on theory, someone not knowledgeable about electrical system cay build it wrong. In one EAA webinar, Mr. Socash revealed he flew his RV7 for five years without realizing the alternator was NOT connected. He only discovered the problem after a long cross country flight to Air Venture
 
I saw the same video since I subscribed to his channel. Of all the things I don't know about building airplane, electrical system is probably the worse of my unkowns. It's hard to think a certified airplane that has to be annual will have electrical modifications that resulted in this serious electrical fire. While building to plan works on theory, someone not knowledgeable about electrical system cay build it wrong. In one EAA webinar, Mr. Socash revealed he flew his RV7 for five years without realizing the alternator was NOT connected. He only discovered the problem after a long cross country flight to Air Venture

Agree on all accounts. And holy smokes on the no alternator story! Must of always had the battery on a charger.
 
Of all the things I don't know about building airplane, electrical system is probably the worse of my unkowns.

It's quite common to fear the unknown. It means you're normal.

There is no reason for electrical matters to remain unknown. Education and recreation, remember?

If you haven't already, study this free download, cover to cover, repeatedly:

http://www.aeroelectric.com/Book/AEC_R12A.pdf

Also buy and study Marc Ausman's Aircraft Wiring Guide:

https://www.aircraftwiringguide.com/
 
Oddly enough, the more I read about electrical topics, and the more time I spend hacking around with my rudimentary schematics, the more I'm actually looking forward to building the harnesses. The fun part will be seeing if I still feel that way when I start actually doing it...
 
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