BACfest 2016 Service Clinic

Bill I can help out for the electrical class and or sub in if job and family interfere with attendance. I've done a fair bit here and it's one of my areas of expertise from my day jobs.

I think the charging system would be a great area of focus and is an area where pilots often have issues especially away from home. A basic multimeter is cheap, light and small enough it can be an "in the airplane" (but not in flight) tool. Many of the aircraft I have seen have had something wrong or missing - everyone I've ever helped someone dig into. Our birds are somewhat confusing as Beech changed the charging system several times in minor ways. There's also a lot of confusion about the interplay of the battery and alternator switches and breakers.

Another good topic would be basic schematic reading especially the quirks of our schematics from Beech in the maintenance manual (12V) and the schematic book (24V).
-=-
Mark
 
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Mark,

Those are the areas I want to hit. No atom splitting. That does no one any good. They need; What is this thing? What is it trying to tell me? What do I do with this information?

Professionally, "I don't help people with airplane problems. I help airplanes with people problems."

Most people and most A&Ps (they are people too) need a little help and encouragement in dealing with electrons. But electrons are very simple.

Please allow me to explain some electrical theory in a way everyone can understand;

You have a task to perform, 'filling a five gallon bucket of water in one minute.'

If you use a 1/2 inch diameter water hose? It will require a lot of pressure!

If you use 1 inch diameter water hose (twice the diameter)? It will take half the pressure!

In this example the '1/2 inch diameter water hose' is a '12VDC system'. The 'pressure required' is the 'Current or AMPS'. The five gallon bucket is a landing light or any work or task we need to perform.

The 'one inch diameter water hose' is a '24VDC system'. It has twice the 'volume (Voltage)' as the the 12VDC system. And only requires one half of the 'current (AMPs)' to perform the same work or task.

So, voltage = volume and current(AMPs) = pressure.

They sit opposite each other on a teertoter (flurcum). As voltage increases, current decreases. And vise-versa.

Electrons are very simple. Most instructors try to over complicate them.
 
I explain that all basic electrical troubleshooting comes down to one of three problems:


  • A connectivity problem (no voltage)
    1. No connection
    2. Trace with ohm meter and voltmeter and physical tracing
    3. Mark's 1st rule of electrical - 95% of failures are simple total loss of connectivity issues
  • A voltage problem (wrong voltage)
    1. Identify with voltmeter
    2. In an basic airplane almost always means a problem with the charging circuit
  • A current problem (not enough current)
    1. Voltage good, behavior bad
    2. Weak/poor connection
    3. Troubleshooting hard
    4. ohm meter often doesn't help identify "flow" problems at high current (resistance versus impedance comes into play too)
    5. Often troubleshoot with verify/redo/clean every connection just because

You troubleshoot them in that order of increasing difficulty. #3 is usually diagnosed by ruling out #1 and #2. Charging circuits and the interplay of an alternator, voltage regulator, battery and over voltage protection are poorly understood even by many "certified" folks. I've met many an A&P that avoids dealing too much with electrons as much as possible, due to lack of confidence or other reasons.
-=-
Mark
 
The "bucket and hose" equation is expressed here;

V=IR

Otherwise known as "Ohms Law"
It is -the- most basic of physics equations, and explains almost everthing in the universe, except women.
As a pilot, it is a very useful thing to understand. As an airplane owner, it is mandatory.

There is one more that a pilot must know, of course!
E=MC2
Einsteins' theory of relativity.
Put simply, "Be smart, or the earth will smite thee"

Wdnd5960 has a great understanding of both these principles. Shame he can't spell!
teertoter (flurcum)
I guess that translates from Texan into FULCRUM!
 
Actually another one that matters for anyone in anything that can crash E = 1/2 * M * V^2. Kinetic energy is 1/2 mass times velocity squared. If you have to crash, then do so as slowly as possible :-).

And as for speaking Texan - at least Central Texan - let's talk pronunciation.

What is the town of "Manor" ? - May-nor
How do you say "Burnett" (Avenue/City/County) - "Burn-it"
What is the dominant geological/topological structure in Central Texas - the Balcones Escarpment/Fault ?- "Bal-co-nees" (long O, long E).

I could go on...but why.
-=-
Mark
 
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Mark in Oz,

You got me! I normally try to proof read my post a few times, to clean and groom some of the Texan out! But I was running out the door to pull a rudder, vertical stab, the interior and three antennas off of a Sierra.

Yes, you gentlemen are both genius class, no argument from me. I agree with everything you both said. You see, I have held an FCC GROL for decades, from BAC in the day when only 3% of the test takers passed it. Before the test was published! I hold the Ship Radar Endorsment as well. Passed both the first time on the same day. So, I've been an atom splitter for most of my life.

I wanted to teach an electrical class at BACfest for the non-atom splitter guys. From somebody who's not trying to talk over anyone's head or impress anyone with vast reams of knowledge they will not remember the next day.

But I will just go BAC to following airline rules; I will sit down. Shut up. And keep my feet off of the seat.

Good night.
 
There are three things I never fully understood. Calculus, how Clinton got re-elected and how electricity really works.
 
wdnd5960 said:
Mark in Oz,


Yes, you gentlemen are both genius class, no argument from me. I agree with everything you both said. You see, I have held an FCC GROL for decades, from BAC in the day when only 3% of the test takers passed it. Before the test was published! I hold the Ship Radar Endorsment as well. Passed both the first time on the same day. So, I've been an atom splitter for most of my life.
Click to expand...

I also have (actually had one, I can't find it) a GROL with Ship's Radar Endorsement. I got mine in '62. Never actually used it, though.
 
wdnd5960,
You stand about 7'13" and you are a Texan. You cannot help but talk over everyones head!

Marty,
There are many more than three things that I cannot understand, but the top three are Women, women and women.
 
There is a theory that states that if woman is ever fully understood by man she will disappear from the Universe and immediately be replaced by something even more inexplicable. There is a second theory which states this has already happened. :p

Back to the original topic - I do think this class is a great idea and Bill's a great guy to teach it.
-=-
Mark
 
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