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I am learning to fly a piper dakota and I found two circuit breakers for which I can't find an explanation:

  1. Start & Acc circuit breaker. I understand that 'Start' is for the starter. What does 'Acc' stand for?
  2. Pitch stab circuit breaker. I would think that this is related to the electric trim control mounted on the yoke but there is another circuit breaker labeled as 'pitch trim'. So what is this one for?
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  • $\begingroup$ acc is usually accessories. On a car this is things like the interior lights and cigarette lighter $\endgroup$ – zeta-band Dec 6 '17 at 22:58
  • $\begingroup$ There are separate circuit breakers each for overhead lights, audio panel, instrument panel etc on this plane. The circuit breaker is a troubleshooting starting point. Why would the manufacturer combine the starter circuit breaker with cigarette lighter circuit breaker? If the cigarette lighter is not working in flight..is it really wise to mess with the starter circuit breaker? $\endgroup$ – Prashant Saraswat Dec 7 '17 at 1:59
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It is for (two) accessories and the starter, they are on the same 15A circuit breaker. The page you want to look at in the POH is Section 7.17 (this is figure 7-11):

enter image description here

I know the image isn't all that clear, but the 15A breaker is on the right side of the alternator buss. It includes the cigar lighter, cabin light and starter solenoid.

Why would the manufacturer combine the starter circuit breaker with cigarette lighter circuit breaker? If the cigarette lighter is not working in flight..is it really wise to mess with the starter circuit breaker?

I'm not sure why Piper put those two things on there, but they did. I don't see it as a problem though. If the cigar lighter isn't working that isn't a problem, you wouldn't mess with the breaker. If it is melting a hole in the dash then yes, you pop the breaker, hopefully you wouldn't need to use the starter in-flight. I would consider the need to pop that breaker (due to heating/smoke) an urgent situation (maybe not emergency, but I'd divert to the nearest airport).

As for the "PITCH STAB", that is probably for an autopilot or altitude-hold system. The Dakota was available with a number of different autopilot options that operate separately from the electric trim system.

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  • $\begingroup$ This is an outstanding answer. I'm not an electrical engineer by training and intentionally skipped the circuit diagram while reading the POH. Will not make the same mistake again in the future. Many thanks!! $\endgroup$ – Prashant Saraswat Dec 7 '17 at 5:33
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    $\begingroup$ The diagrams in the POH are intentionally simplified so that you don't have to be an electrical engineer to understand them. They are a good thing to know, at least how to read quickly, in case something happens (like the cigar lighter smoking in flight) so you know what breaker to pop. The other method is to pop them all and turn them back on one-by-one until you find the one with the issue, something that can take significant attention away from flying/navigating. $\endgroup$ – Ron Beyer Dec 7 '17 at 5:40

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