AeroElectric Occasional
GMCJetpilot: "No offense to Bob, but OV relays are a step backwards."
January 26, 2007
For some years the AeroElectric List has been host to some conversations involving
one "GMCJetpilot" who claims a great deal of knowledge, experience and understanding
but who has yet to demonstrate it. He has consumed hours of everyone's time in
attempts to get down to the science of applying our art to a practical world. Some
months ago he was politely asked to take his disruptions to somebody else's classroom.
For a time, purposeful decorum was restored.
However, it seems that George's hot-button is supported by a faith in the marketing
hype for internally regulated alternators wherein he has demonstrated no first-hand
understanding of their design and has brushed aside design goals of individuals who
do not share his faith.
This has been a trying experience made more difficult by the fact that we don't even
know who this fellow is. Everyone else on the AeroElectric List participates under
the bright illumination of disclosure: "Here's who I am, here's what I'm about and
here's how I'd like to work together to increase understanding." George chooses to sit
at the edge of the sandbox and throw sand while hiding behind his pseudonym.
Since George has resumed this behavior a few days ago, I thought it would be useful
for newcomers to the List to have some understanding of what we've already been
through with George. What follows is a SMALL excerpt of the hours of conversations
I've expended with George's circular arguments and intractable ignorance.
At 09:00 PM 8/7/2005 -0700, you wrote:
AeroElectric-List message posted by:
From: "Robert L. Nuckolls, III" nuckollsr@cox.net
Subject: Real data on Over Voltage Protection and Control of Internally
Regulated Alternators.
It depends on your paradigm
That was my whole point. Bob you are focused on one small aspect. Aviation safety
is a much broader subject than voltage regulators.
I'm sorry, we WERE speaking about voltage regulators,
are there other aspects of aviation safety we should
be considering for this discussion as well? For the past
70+ years, folks flying airplanes have had switches on the panel
that offer (1) absolute control over all sources of power in the aircraft
and (2) has a remote probability of a failure that propagates across
multiple systems. The FAA requires that I work within that paradigm when
offering up new systems for certification. My customers are pretty
happy with that model too.
You missed the point. Opinion does guide your perspective. I don't worry what the
FAA says.
The above at least was not opinion or perspective. It was
a statement of simple fact. I'm not saying that you SHOULD worry about
what the FAA says, but I will suggest that not everything the FAA says
is BS . . . there are some useful ideas to be gleaned from FAA positions
on system design and operation. I only mentioned it because the FAA is
one of many participants who drive my design goals.
I'm completely mystified by your statement. How does the fact that
the FAA will or will not bless any particular reasoning make it
an automatic no-brainer for someone building his own airplane?
This isn't about regulations or opinions, it's about design goals
that satisfy the paradigm under which the owner/operator of the
end product. 99+ percent of OBAM airplane builders are comfortable
with and most understand the paradigm that controls how certified
airplanes operate.
Bob don't be mystified. That is so condescending. What I wrote was so bewildering,
you became disoriented and confused? Wow I did not know my words had the power to
mystify. No one is proposing a panacea here Bob and were ae a lot smarter than you
give us credit for.
It's condescending to admit a lack of understanding on my part? What
word would you have me use?
Do you have data about how the various IR alternators operate such
that you can DEMONSTRATE that anything with ND's name on it will
operate in the paradigm that applies to the vast majority of airplanes
flying? If not, then your recommendation is not backed up by demonstrable,
consistent behavior and is in fact, preference for a different taste in
your bowl of stew.
Do I have data? Bob, that is an inane thing to ask. There are 148 models of ND
alternators with internal regulators and internal fans ranging from 30 to 130 amps.
There are 66 models of ND alternators with external regulators and internal fans
from 90 to 136 amps. Plus there are another 15 various models with external fan
models. There are a few million ND alternators in daily use, 24 hours a day, every
day of the year working with excellent performance and reliability. If this does
not prove, demonstrable and consistent performance characteristics, to BAD. All
your posturing is absurd. You seem to lack common sense and reasonable rational.
These are experimental planes. If you have never been in one, there is a warning
placard that informs passengers that an experimental airplane does not meet
standard aircraft certification standards. Bob, I never said my recommendation was
a substitute, replacement or better than your brilliant concepts, architecture
and philosophies.
Forgive me, the DATA I was referring was about schematics and/or operational
characteristics for any internal regulator that would offer a system designer
exactly how his/her choice of alternator would behave under command and
control of small wire coming out the back? Further, what are the failure modes
for the regulator itself? The same data would be necessary for you, me or anyone
else to deduce failure modes and operational characteristics under those failures
and how we might (or don't need to) deal with it.
I've stipulated many times before that the fleet of IR alternators have an
exemplary track record . . . as do the B&C alternators.
None-the-less, folks continue to come forward with their failure experiences.
Not a "current generation ND alternator? Don't know. Not a stock regulator?
Don't know. Would a well considered ov protection system of ANY flavor have
saved the day? Probably . . . likelihood of dual failures in same system on
same flight are extremely rare. At least one customer with the b-lead contactor
and OVM-14 crowbar module has written to me expressing relief that the system
was in place when his IR alternator went tits up.
Bob, I am glad people write you to relive themselves. I think part of that relief is
from all the misinformation and rumors about IR alternators you spread.
You mystify me again sir. You brush aside first-hand alternator failure experiences shared
with myself and others on the List as figments of their imaginations brought on
my my nighmarish mis-information and rumors?
I have all my statements about internally regulated alternators in the archives.
Please give me specific statements that you are characterizing as rumor or
misinformation. If I have been incorrect in any way, it was an error which I will
be pleased to correct. Please cite any instance. I'll look it up, rectify the
misconceptions and add it to the appendix of this posting.
With all the sensationalized talk it is easy to see how someone could have an unreasonable
heightened sense of concern. What folks continue to come forward? You are the master
of inflammatory insinuation.
I believe in precise speech. I never insinuate anything. I strive
to communicate in simple-ideas (fundamental truths). The fact that you've
become inflamed over anything I've written is unfortunate and not my
intent but also not my problem. Please don't paint me as having any kind of
under-the-table, ulterior motives or agendas. It's simply not true.
How many accidents have been caused by an OV and did they involve a ND alternator?
ZERO. You have a better chance of your 0-2 gage-battery cable grounding, burning
thru the engine mount or just falling off. Electrical system failure is a very
small % of the total GA accidents. Statistically, regardless of where you put the
regulator or if you use a crow bar or not, your accident statistics will not change.
How did accident rates get into this discussion? I don't recall ever
having suggested that this discussion has a thing to do with accident
reduction.
It's about doing a simple task assigned to things like circuit breakers.
A breaker keeps the wire it feed from catching fire. It also isolates a
failed branch in the system from propagating it's failure to other components
of the system.
Since the ALERNATORS holds great potential for an energy intense failure.
It's perfectly reasonable. It's the ONLY device in the airplane that will boost
bus voltage beyond levels ALL other accessories will withstand. I've never read
of an accident where lack of ov protection figured in the chain of events. However,
there have been many instances where the OV event has needlessly damaged other other
system components at great expense.
But do you agree that the risk is not zero? In fact, one of our brothers
here on the list reported such an incident recently. If I were trying to
convince someone of anything, I could have wished that Jack's failure would
have occurred two hours out, at night, over mountains and took out a bunch
of radios to boot. When one is looking for propaganda fodder, the sweat-drenched,
nail-biting stories are much more useful. Gee Jack, you let us down. All you\
lost was a fuel level indicator!
Bob that is just more emotional sensationalized comment is not worthy of an engineer,
that you claim you are. You are clueless, I mean ignorant to the meaning of incident.
This is what a pilot would do Bob: Over the mountains you loose your alternator; Turn
off all your non-essential electrical stuff and continue to fly. You pull the ALT
circuit breaker and the B-lead breaker. When you get near your alternate (nearest
suitable airport) you turn the electrical stuff back on and land. Modern avionics
like GPS pull a few 1/10th of an amp, so you could run on BAT power for a while.
Nighttime you should have a flashlight. If you have a glass cockpit you should have
enough battery power for at least 30-45min VFR and an hour plus for IFR. If you also
have electronic ignition and fuel injection, all electronic you would need a bigger
back-up battery. Dual alternators?
My personality flaws not withstanding, this was an attempt at a bit of
humor . . . I WAS admitting to the increased propaganda value of spectacular
failure stories and lamenting the fact that if I WERE operating in a mode
of exploiting people's unhappy events, it was too bad that Jack's story didn't
have more "red meat" in it.
You propose to lecture me on system reliability using words that suggest you've
never read Chapter 17 of the 'Connection. Do you have a copy by the way? If
not, shoot me an address and I'll send you one at no charge. If there are errors
in Chapter 17, please be specific as to what needs modification.
My viewpoint is use a Lycoming with a mechanical fuel pump, at least one magneto or
P-mag. A carburetor or mechanical FI does not need electrical power either. The Dynon,
GRT-EIS-4000, Garmin and other misc items are pulling about 5 amps total.
The Dynon and GPS have self-contained batteries as well. My engine is electrically
independent as I feel it should be. I understand fault tolerance Sir.
Agreed. Sounds like this stuff would run from an e-bus very nicely.
You absolutely missed the point. Again, this has nothing to do with how
much this system would please or displease me, the FAA or anyone else.
It has everything to do with operating within the paradigm (which the
FAA happens to like - as do the vast majority of OBAM aircraft builders).
Bob, no you missed the point again. /Operating within the paradigm/ is gibberish
that has no practical meaning to anyone. Common sense is the paradigm Bob. If you
can't dazzle-em with facts, baffle-em with the word paradigm.
Forgive me please . . . choose a phrase more to your liking. How about
"design philosophy" or "design goal" . . . I like "paradigm" because it
takes fewer keystrokes but if you believe I'm trying to dazzle anyone
with meaningless gibberish, I'll not use it any more.
It is not an affront to you or any device you have worked on. I have studied your
every word and understand it. I just don't want a device that SHORTS to ground to work, no
matter how clever or certified it is.
Why was it not sufficient to cite that design goal at the outset and
work toward an alternative configuration that satisfied your desire? Both you
and Paul seemed to need some justification for offering alternatives that
depended on demonizing the crowbar OV protection system. When I set out
to do the crowbar system 25 years ago, there were design goals that
avoided some pitfalls and expenses of current technologies. I didn't need to
promote the idea based on hammering the work of those who went before me, it
was sufficient to offer the new idea and explain how it helped me eliminate
some problems.
I don't really care what the FAA thinks as long as I get my paper work signed. It is
my butt and for a VFR plane, with no main buss electrical dependency to stay in the
air, I am safe. What else can I say? What don't you understand? I designed my system
to eliminate the need for a crow bar and external regulator. From personal experience
with a ND alternator in my cars and plane, I expect over 4000 hours of operation
before failure (200,000miles & 12 car years). So when my alternator reaches 2000
hours or 8 years I will remove and replace it.
Very good. You've illustrated your design goals quite well. May I offer
another feature worthy of consideration? When you use a breaker
to open the b-lead of a runaway alternator, at the time the contacts
first part, the breaker will already be several hundred milliseconds
into a warm-up cycle in anticipation of opening the circuit.
As the contacts first break, the very tightly wound "spring" in the form of
a 50-70 amp pull-up on bus voltage will build the voltage across the opening
gap very quickly. Peak voltages to be considered are at least 100 and probably
pushing 200 volts.
If the arc does not go out, then in seconds following breaker operation, you'll
have something in excess of 5,000 watts of heat being dumped into the interior
of the breaker. Being a molded plastic part, there is risk that it will begin
to change shape rather quickly and with lots of smoke to boot.
Click here for an example of high current contact failure in a non-metalic enclosure.
While wrestling with the IR alternator control issue, I favored the control of
b-lead circuitry OUTSIDE the cockpit and by means of a system mostly enclosed
by a metal housing with as shown in this picture.
I've been working an issue on some certified airplanes where breaker failures have
put smoke into the cockpit. We have to take these things very seriously not only
because of the operational aspects of upsetting a pilot but because of the nature
of DC power systems where established arcs are difficult to put out, dump out a lot
of energy and are not well contained in a plastic housing.
You remind me of individuals who have a lot of opinions about a book they've never
read. The crowbar OV protection system IS certified sir, several times over. I've
stated this numerous times in this thread. All of B&C'S many STC'd installations of
both belt and pad driven alternators use the LR/SB series regulators all of which
have crowbar ov protection.
I must remind you of yourself, since you talk about stuff you are clueless all the time.
When the guy with the Subaru had the electrical failure you pontificated and criticize
with little knowledge of facts.
Hmmm . . . I don't recall the specifics, what was it I said that was so baseless
in fact? Please point me to some linkage that I can review. I'll be pleased to
revisit any assertions I might have made.
When you stated how B&C starters are better than Sky Tec with bushings and blaa blaa,
The SkyTec guy put you in your place.
Forgive me, but this now seems to be more about let's shoot Nuckolls off his
perch than about science or considering the tradeoffs in design goals. How does
SkyTec figure into this discussion? But if you want to add SkyTec to the discussion,
you'll need to give me linkages to the words in question.
You should have apologized but you replied with something stupid comment about lets do some test.
I don't recall the conversation now. I'll look back through my OutBox and see if
I can snag it. But as I suggested to Paul, repeatable testing and sharing of data
gathered is a courtesy that engineers and scientists afford each other with a goal
of accurate communication of fact and lucid interpretation of results from which
good decisions are made. I will apologize for mis-statements of fact and
behavior that does not reflect my goal of conducting myself in honorable ways but
you're going to have to be specific. I'm not going to launch into any big research
projects over this discussion.
Again you did not have the facts. I am not perfect but you are ignorant.
I agree that certification is not the Holy Grail of function or performance
and wasn't using it as such. You offered lack of certification as a useful data
point when considering B&C's products, I was only attempting to update your
mis-conception. The "book you did not read" was a collection of B&C's data sheets
that accurately disclose their achievements in the suite of products offered to
aviation.
You also remind me of someone who loves to argue.
There's a very accurate perception. As both engineer and teacher I am duty bound
to argue in favor of accurate critical review using good science and honorable behavior
with respect to my fellow workers and my customers. Since I do very much enjoy this
profession, it stands to reason that this discussion could be exhilarating. You do
not seem to share this perspective which is disappointing. I'm not doing this to
"shoot you off any perch."
I see B&C has a standby alternator system for the Bonanza and C210. Good for B&C. So I was
not up to date. Sue me. Apologies.
Lawyers give me allergies. I'll pass on your suggestion but if you must
apologize, I accept.
Do they have any STCs to replace the main alternator on any plane? If no, then why?
Easy, they have one overworked, under paid guy doing ALL of their STC's. He is
peddling as fast as he can to produce results on the tasks before him. Bill has
elected to attack the standby alternator market first and seems to have made a
good penetration. As a matter of fact, Tim is currently working on an STC to
put the L-40/LR-3 combo on Super Cubs . . . the very same installation featured
in all the kerfuffle with the FAA back in '97.
If you would like an STC for your aircraft, give them a call. It's probably somewhere
on Tim's long list of things to do.
(Since this the original writing, B&C has acquired some STC's to install
the L-series alternators and LR/SB-series regulators [all fitted with crowbar
ov protection systems] on type certificated aircraft)
-----------------------------
You couldn't offend me if you tried. I won't permit it. You do amaze me with your
lack of understanding as to what the real issues . . .
There you go again. What does that mean, I WILL NOT ALLOW IT. Whatever Bob. I was
making a sincere jester of concern and you throw it back at me as if I was
inconsequential and beneath you. I understand I am not worthy and of no importance.
It's quite simple. Nobody can offend you unless you allow it.
If individuals offer language citing facts and conduct rational debate,
then there is no reason for anyone be offended. If the language
contains words designed to hurt or to propagate un-truths, then
one may CHOOSE to be offended or to take passive notice. I have
only so much emotional capital to invest in my relationships with people.
Therefore, expenditure capital on being offended is a poor utilization
of a limited resource. I choose instead to take a non-taxing notice of
most ignorant or vindictive behaviors.
The issue before us isn't about ov protection. It's about control.
Does your ND alternator of choice turn ON and OFF at the flip of a
switch? Once it's in operation, can it be turned OFF? Do all
alternators with the ND brand on them operate in this manner? How does
one insure at the parts counter that the alternator being considered
will operate under the currently accepted design goals?
Engineers? Bob you can't control everything, you only think you can.
Say again? When my boss gives me a design goal that says
"control this" I will either (1) control it or (2) explain
to him in very lucid terms why it cannot or should not be
controlled.
I can't think of a reason why I would turn off a perfectly good alternator with
the engine running. If it did crap out I would pull the B-lead CB in my panel.
That would essentially isolate it from the electrical system. (Yes I want control
of my B-lead and opt NOT to use a FUSE under the cowl where I can't access it,
as you suggest.) If I did not have the CB for the B-lead I could shut the BATT
master off. The engine would continue to run. The Dynon and GPS would be powered
by internal batteries.
When there's smoke in the cockpit, one usually wants to shut off every
electrical power source. If an alternator fails a diode, it may generate
a lot of noise that prevents utilization of radios battery-only. If you
have two alternators (Figure Z-13 for example) you want to shut down
the main alternator to preflight the standby alternator. Figure Z-12 is
installed in many Bonanzas. We shut down the main alternator to see the
standby machine pick up the load. There are probably others.
If you never have a need to shut the alternator off from the panel, then
then you're proposing a new DESIGN GOAL. Which is fine . . . but be
prepared to explain it in sufficient detail that everyone knows the
physics upon which your recommendations are based . . . and they understand
and accept the new DESIGN GOAL. This has nothing to do with opinions, only
facts and customer perceptions of value in the proposed DESIGN GOAL.
I don't have customers. I am an individual and have stated so. As I clearly stated
your paradigm (oh I hate that word) is valid and needed based on your position as
guru. I dont have to prove anything. I have been honest in saying that ND alternators
have gained over a thousand of hours on single airframes. Personally 800 hours of ND
time in a plane and a total of approx 6000 hours in three automobiles (with ND
alternators). As for the auto applications, the highway safety foundation has never
had a problem with ND alternators, which is not true of many other alternators.
Since records are not kept for experimental fleet, I am going by my experience and
those of other RVs (some with 2000 hours) over 15 years. Not real scientific but
it works.
Then why are we having this discussion? It was my understanding
that when we started this List, it was to be a forum for
the gathering and sifting of new and old ideas looking for ways
they can be assembled in more useful ways. It's also a forum
for helping the neophyte builder take advantage of these
ideas from the perspective of understanding rather than
"buy these parts, hook 'em up like this and TRUST ME, it will
work."
We've already explored several reasons why the pilot wants to have
control over ALL his alternators but none of these are drivers
for your design. Given all the in-bound cabbages and tomatoes about
designs I WAS trying to perfect I presumed you had an alternative
configuration to sell, academically if not financially.
You and Paul have alternatives with no relationship to configurations
other folks are considering and I'm trying to help evolve. I've offered
space for additional Z-figures in the 'Connection to illustrate your
concepts . . . but if I understand what you're describing now, it's
classic C-172 except for an internally regulated alternator that
must be controlled by pulling the b-lead breaker. This is the essence
of the last drawings I saw from Van's and I'm not interested in
offering up slightly modified C-172 systems as exemplary advancements
of our craft. If it fits your needs, that't fine too. You don't even
need to defend it UNLESS you're on an intellectual selling mission in the
world of ideas.
-----------------------------------
Chance-Taker? Bob you have such a PIN HOLE view of the world , aviation and aviation
safety, or at least you sound like it. I am bewildered and confounded by your very
ignorant words. I am dizzy with disbelief. You dont know me and I am a very
conservative ATP. This is just another feeble insult and a smoke screen for the lack
of an intelligent comment with substance. I dont know what is romantic Sir, but I
read what builders want to do. It is clear they are trying to make it perfect of
totally fail-safe. Which is impossible with any of your suggestions or paradigm.
If you like I will explain how an air transport category planes electrical system
works to illustrate how unsophisticated our little DC electrical systems are.
Sure, we all take chances every time we pull out of the driveway
in our cars or break ground at takeoff. Did you climb into a car and
go without some instruction? An airplane? Did you launch into an airplane
construction project without surveying the terrain ahead?
This would be amusing if it weren't so serious. In one breath
you extol the virtues of a "brand new" ND alternator while
in the next, you cite the value of de-rating to 30 amps,
supplying cooling air, modifying operating techniques that
don't bother the alternator on a C-172 but might be stressful
on the brand new ND . . .
Well Bob, for someone who claims to know how an alternator works, you appear to have
a lack of any comprehension. I am not extolling any more than you are singing about
the 7th wonder of the world called a Crowbar. WHAT DO YOU MEAN?
First, I've never held the crowbar system up as anything miraculous, it is
simply what it is. One of several ways to deal with a runaway but controllable
alternator. If you wish to use other means, I couldn't care less. The only
reason the crowbar design is even a part of the current discussion is because
you and others have erroneously or maliciously drawn it into the discussion
and compelled me to defend it. Now, in the act of defending it you accuse me
further of raising it to celestial stature. I guess my defense must have
been effective. If you can't "get me" on the science, then let's go after
some imagined marketing hype.
The point of the comment about cooling/derating was in reference to your
willingness to accommodate the ND machines vulnerabilities to it's own load
dump spike by never expecting to control it. Then followed up with more
concessions for cooling and de-rating. Yes, we do cool alternators and
generators, and sometimes de-rate them. Based on load analysis, hot climb
cooling tests, etc. But with reason dictated by tests and numbers, not as an
off-hand recommendation intended to assist the neophyte builder. All-in-
all, not an encouraging thing for a new builder to ponder.
---------------------------
You cite facts not in evidence. The LR series regulators
were tuned to provide the slightly under-damped servo response
for step functions in both command and load. It's a classic
task for tailoring servo response. If the internal regulator were
so whippy, LOAD DUMP ISSUES WOULD NOT EXIST. It's a regulator's
inability to control the worst case load reduction that
causes the high energy voltage transient.
You cite facts not in evidence? Bob, what the heck do you mean? Whimpy? What kind of
engineering term is that? That is how they work by design.
Yes, you're exactly right. By the way the word I used was "whippy"
not "whimpy". What we see is what we get.
The internal regulators are optimized for performance
under normal operating conditions with a battery in place.
Since the internal regulator is NOT a mathematical engine
with advanced capabilities under guidance of software, it
has very limited ability as a PID (position, integrating,
differentiating) controller. The (D)ifferentiating functionality
can be optimized for either the normal load or load dump events
but not both. Hence, the effects we see in virtually all
regulators, internal or external, under the load dump event.
"Whippy" was used to emphasize the inability of the simple circuit to
mount so complex a task as dealing with both kinds of event. ND regulators
don't do it, B&C regulators don't do it either. But don't need to in the case
of controlling the alternator because the b-lead contactor is
not necessary and no part of the system is at risk for turning
the alternator on or off for any reason.
AGAIN FOR THE 10th TIME CUTTING THE B-LEAD OF AN IR ALTERNATOR IS NOT GOOD FOR THE
ALTERNATOR. IF YOU WANT A CROW BAR USE AN ALTERNATOR WITH AN EXTERNAL REGULATOR, OR
TAKE YOUR CHANCES WITH FAULTS CROW BAR TRIPS. GO AHEAD, USE A IR ALTERNATOR, IT IS OK
WITH ME. EVERY ONE KNOWS RUNNING AN ALTERNATOR NOT CONNECTED TO A BATTERY IS BAD BAD
BAD. WHY IS THIS HARD TO GRASP BOB?
Never said it was. What I said was, If you need to control a failed
IR alternator in the ov runaway mode, here's our best whack at doing it.
This has nothing to do with ND, or any other brand of alternator and everything
to do with a condition common to all internally regulated alternators. It's
you who have raised the ND product line to celestial status . . . and I do
not doubt that it's deserving of this recognition. But I'm not ready to
recommend IR alternators if they happen to have "ND" embossed on the cooling
cover. Too many questions of configuration management over which I have
no knowledge or control.
Never said it was good. But there are folks who have stated this mode of
operation as a DESIGN GOAL. For example, the electrical system in Bonanzas
and Barons offer alternator only operations with separate switches for battery
and alternator. In fact, we were given and ultimately complied with a design goal
to provide a regulator that would not interfere with a Bonanza alternator's
ability to come on line totally self excited. I don't like operating sans
battery but that was the bosse's DESIGN GOAL and I complied with his directive.
Even today, once the standby alternator is installed, the POH calls out
shutting the main alternator off to test the standby machine. A perfectly
acceptable thing to do with alternators that can be controlled, not so good
for those that cannot.
You claim to understand failure analysis. I doubt it. If you were driving your car
and the b-lead shorts (before the fuse), would you want the alternator to burn-out
(fuse) or keep working and act like a welder and set the car on fire?
Your point is well taken . . . the potential for EITHER
a properly working or failed alternator to output a LOT
of destructive energy is great. I have offered questions
to ponder that address this point. I'm sure there are
others and this is the foundation for my suggestion that
being able to break the field circuit from outside the
alternator is the simplest, safest, most convenient
way to manage any alternator working or failed.
(I have no idea what you will say, really, you would argue with a rock.).
Only rocks that talk and want to help people design airplanes.
I've been doing failure mode effects analysis studies for my bosses for
30+ years. If I were so bad at it, I would think I should be attending
a tool crib by now.
We know the OV trip caused the demise because after this event the alternator
did not work anymore.
I'm lost, are you talking about the event reported to
Van? The only one I'm aware of the builder stated that
he cycled the ON/OFF control switch manually with the
engine running and at some point, the alternator was
damaged.
Without failure analysis data on the alternator, we don't
know if the regulator went belly up in a passive or runaway
modes. We can safely guess that the alternator's response
to being switched ON/OFF manually produced SOME magnitude
of a load-dump response. It seems reasonable to guess that
failure of the regulator is attributable to the manual
operation of the switch followed by what MIGHT have been
a response on the part of the OV protection system to
disconnect a runaway alternator. If you have any better
data on this or any other instance, I'd be pleased to have it.
ND engineers no doubt assumed this would be a rare event (because they don't
recommend OV cutouts by default. There are no OV relays in non-aircraft applications).
I would hope ND's engineers assumed nothing. They should have
delivered to design goals that fit their customer's needs with
a high degree of reliability. I have no reason to suggest they
didn't achieve those goals. ND's folks have probably never talked
with my customers. It would be interesting to see what their
recommendations might be for accommodating design goals unique
to the aircraft world.
The IR has many functions and one of them looks at the B-lead. While under load
it will assume a short or other fault, which it does monitor (because ND said so).
Also the IC chip is connected to the B-lead and it just might be too much for it.
SO WHAT. This is condition is avoidable. ND accepted this failure mode because
it is not suppose to happen and is safer than making a welder out of it.
I have no argument with their DESIGN GOALS nor with yours.
Bob I think you have IC envy. Yes Bob more transistor means more features and
performance. You heard of computers? Well they have millions of transistors on a
small chip. More transistors the faster it works. If you built a computer like you
build your B&C VR, it would be the size of a house. I would think you could grasp
that. The IC chips inside most modern alternators does have logic circuits
(digital processes) and self-fault monitoring. DENSO will not send me the schematics
to their proprietary IC design. What I do know about special IC chips is they are
made by a handful of manufactures. They all seem to have similar features. Here is
a typical IC spec data sheet.
That's a great chip. But it's a PID controller (or VID in the
case of an alternator) with limited ability to deal with ALL
cases of load transient. After this chip has been optimized for
NORMAL operating conditions, it's ability to deal with the
abnormal (load-dump) will be about as limited as with the
earliest 2-transistor regulators (or B&C's transistors plus
IC's design). Until someone goes the next step with a computing
engine of some kind with the agility to sense and react to
the non-normal, load-dump event. What we see today is about
a good as it's going to get . . . now matter how many transistors
they put on the chip.
Another interesting feature in this chip can be deduced by studying
the fine print. It has OV WARNING but no OV CONTROL.
-----------------------------
It's Eric's product as I recall, not Paul's. Further, it has
nothing to do with nuisance tripping. It illustrates a means
by which an IR alternator can be CONTROLLED irrespective
of the reason for controlling it. OV protection is but one
more layer on a system that's already several layers deep.
My mistake, yes it is another layer. I have read spec sheets on devices. If you
must use a crow bar on an IR regulator it might be a good add on (another add on).
It might help the OV relay from arcing as I think you and Paul have argued about.
I don't think we've had a single disagreement on the
issues surrounding arcing at the disconnect relay. Similarly,
I've suggested that you consider the same arcing phenomenon
at your b-lead disconnect breaker. It's the same dragon
to slay irrespective of the controlling technology.
------------------------------------
You're entitled to accept any paradigm you wish. Just be
sure your audience understands the paradigm shift when
the proposed system does not operate like the one in
a C-172.
Thank you for telling me I am entitled to an opinion. I don't need your permission
to have an opinion but thanks. Let me make it simple for you, the engine should never
stop turning in flight. Most GA planes have engines with no reliance on external
electrical power, or should.
This was in no way intended to be a granting of permission. I was
erroneously belabored of the notion that you were trying to promote
some new DESIGN GOALS for consideration by folks who frequent this List.
Since you've made yourself clear on this point, I'm only offering this
response as a courtesy of trying to clarify my position. Since you're
only discussing your personal DESIGN GOALS then this is purely an academic
discussion between us which others are free to use as they wish knowing
that there are no new ideas to be considered as part of their own
design deliberations.
That is a good thing and should be emulated at all cost . . .
Electrically free engines? It's not in the cards my friend.
. I understand Auto engines need power for the ignition/fuel injection and pumps.
That is one reason why I would not use an auto engine. However an IR alternator
could still be used, but you should have an isolated power source. You never
considered a DC-DC converter (battery charger) to charge isolated battery. This
is used on transport category planes.
Absolutely, I've written several white papers for start-up aircraft
companies suggesting that they look into wild-frequency AC
systems and used DC/DC converters for limited support of
cranking batteries and avionics. All major power loads should
run from the 208V/3-phase engine driven alternators. Wire
sizes drop dramatically and system efficiencies go up too.
Unfortunately, there are no wild-frequency generators or
accessories suited to the light aircraft market . . . in fact,
not for the light Biz Jet market either. But I'm watching this
technology and MIGHT be encouraged to suggest consideration
on this List at some future date.
----------------------------------
Numerous folks have experienced failures of IR alternators. Some
of them were ND alternators. Since we might expect to be in
communication with perhaps 5% of the OBAM community, it's not
a stretch to suggest that 3 hard failures I'm aware of over
the past 8 years has been repeated 20X for the community at
large.
Numerous? OK Bob what ever you say, Failures. Hard failures? You don't even know what
the word incident means. Like you asked me several times above, DO you have data?
Prove it to me. You are throwing out numbers: 20 times, 3 to the power of perhaps?
You are real loose with the numbers. What does that mean? What hard failure? What
happened? I mean really Bob, you are hypocritical when you ask for data and expect
to give none in return Sir. Other wise it is hearsay, innuendo and rumor. A few of
these I tracked down where totally irrelevant and where factory planes with external
regulators. Forget the Failure analysis Bull, how about some simple details. Basically
WHAT HAPPENED? My I suggest if you had a smoking gun to support your view you would
say so.
You're a relatively new kid on the List so you'll have to forgive me
for assuming that you've been aware of failures discussed here. We have
two, hard failures that produced damaged accessories in the aircraft and
caused the builder to remove the alternators for repairs. One incident was
reported recently by Jack, another was several years ago reported by Peter
Graichen (sp?) and discussed on page 4 of this document.
The third was in either an e-mail or telephone conversation
I had with a builder some time ago. His external b-lead control and ov protection
system operated as designed and saved him some grief. I don't know the brand
or model of the first two events, only Jack's which he says was ND.
[I constructed this webpage many months ago but never published it. Since the
original writing, numerous additional cases of IR alternator failure have been
reported . . . George would brush these aside asserting that we have "no data"
on the failures. I'll suggest that smoked electro-whizzies in builder's airplanes
as the result of alternator failure is all the data we need!]
Jack's experience was not mitigated by the fact that his alternator was "not
in a wild run-away" . . . the battery was the only thing standing between his
failed alternator and all the other elctro-whizzies in his airplane. If the
battery had been used up or even disconnected, the voltage would rise much
faster and much higher.
That is the sum total of three hard failures I know about. Given my limited access
to all that goes on in the OBAM community, I was hypothesizing that for every
event I knew of, there were probably many more that I didn't know of.
Oh, Bob you don't know that. It was mitigated by the fact the voltage regulator was
still functioning; it was no big deal. Voltage was between 13-16 volts.
How do YOU know that?
I am sure in a few years this case will grow into a fairy-tale where the pilot was
electrocuted and the plane bust into flames from exploding avionics. It is all sensation but no
facts. Take a deep breath. No harm no foul. Yes the battery helps any alternator.
That is why my you don't disconnect it from the battery normally. If you do the
alternator might be damaged.
Are you suggesting that the regulator was still functional
but only "confused" to the extent that it was now CONTROLLING
at 16 volts? That's a very interesting failure mode. A resistor
suddenly changed value? A voltage reference decided to move a tad?
I musts confess, the only hard failures I've investigated in
regulators involved passive failures (shut down) or active-
aggressive failures (ov runaway). The preponderance of my experience
suggested to me that ov runaway was the failure mode he was
seeing . . . especially in view of the bench tests I conducted
that demonstrated a battery's ability to hold a runaway alternator
down in the 16-18 volt range during an ov event.
In fact, your own design goals will DEPEND on a good battery
to stand off the alternator while you react to the event.
You'll need ACTIVE NOTIFICATION of high voltage. Some
suppliers of products to aviation embrace the notion that
their products should stand off 20 volts for 1 second or
more, this gives you a window of opportunity to react
to the high voltage warning light and pull the breaker.
The only remaining dragon to slay is to make sure that
the potential for fire at the spreading contacts propagating
outside the plastic housing of the b-lead breaker is accounted
for.
----------------------------------
If you're looking for component reliability, you're correct. If you're looking
for system reliability, my data is backed up by FMEA supported by 15 years
of field history and a lot of experience in conducting such studies.
There you go. You have 15 years of crow bar data in experimental aircraft? Wow. Well
the basic ND design has been around for well over 15 years. I believe you, but how did
you get the data. You claim you conducted 15 years of field history study. How many
are in service? What about the failures happening, which you have no idea of? One
weak link in the home built world is there is no requirement to collect maintenance
data. You will see maintenance bulletins the FAAs prints pertaining to all planes
and sometimes a Kit plane will be in it, but most non A&P builders of experimental
aircraft don't report or read this publication. There should be a FAR that requires
or makes it easy for builders/repairman to report maintenance issues, including
electrical. That way we would know whose alternator is failing.
An FAR? Please no. If you're referring to Service Difficulty Reports,
those are solicited from only a small segment of certified aviation
and even then, they're not mandatory.
Your field history data is no less anecdotal than my data.
There never have been nor will there ever be a formal study
by either B&C or ND (beyond warranty) so please don't dump
that bucket of cold water on the discussion.
I'm suggesting that given thousands of B&C systems flying combined
with both their stated policy of "no unhappy customers"
for service beyond what others cut off with a warranty period,
my anecdotal information about B&C's history is much better
than your anecdotal about ND's history. I've worked for B&C
and I have a reasonably close relationship with them now.
I have no fantasy illusions about the component reliability of ND
nor do I have harbor such illusions about B&C. In fact, field
history of either company has nothing to do with achieving
DESIGN GOALS. The only reason I even mentioned my experience
with B&C was because of an incoming cabbage inferring that
the crowbar concept was ill-considered, evil and would never
fly in the marketplace much less become certified on your airplane
or anyone else's.
I'll suggest we eliminate field history of any/all companies
from this discussion and concentrate on DESIGN GOALS.
I think you are super defensive and sensitive, Sir.
You read things into the words which are not there. They're intended only to
illustrate the foundations for what is admittedly anecdotal data for feedback
on system reliability and consumer satisfaction. Again, I'll suggest that
including B&C or ND's admittedly un-scientific "field history data" have nothing
to do the discussion at hand. I was only responding to your erroneous
assertions of B*C's position in the market.
As I mentioned before, if I have an emotion to ascribe to my participation in
this discussion, it's "enjoyment". It has been enlightening too. Otherwise I
would not have taken the time.
I wish to point at nothing. I don't even know about all the past problems. I am not
trying to discredit anything or anyone. I think B&C is over priced not defective.
However I think many comments regarding the danger of using an IR alternator ignores
the high degree of reliability.
I have never said that the IR alternator was dangerous. I've only said that there
are failure modes that cause an OV runaway that cannot be controlled from the outside.
These are simple assertions of fact. You can ascribe whatever degree of comfort
is offered by your perceptions of field history. When people look to me for ideas,
it's best not to qualify any recommendation based on a particular brand if it
can be avoided. Figure Z-24 didn't speak to alternator brands, only IR alternators.
The ND is an unknown since we cant look into the IC chip. However that is moot since you EXPERTS
have isolate the weak link, the field driver transistor, not the IC chip. As I said
the ND engineers are NOT ignorant and these products are very mature. Regardless, you
can always pull the B-lead CB manually (if you have one and you should.
I've not attempted to isolate anything. There are failure modes that will result
in runaway. If you're comfortable with your choice of alternator such that this
simple statement of fact can be ignored, I'm pleased for you. But I cannot embrace
it as a teacher because I just don't know.
If you want to protect an individual piece of avionics, you can use a device like a TransZorb
(tm) or Mosorb that will break down at a set voltage like a zener diode. This will
blow the fuse or CB for that item (like a crow bar). This may not be necessary since
most modern electronics which have internal OV protection and can take 30 volts and
60 volts spike (except icom a-200). Also no one can put an exact max voltage on an OV
condition. The last one was 16 volts. Yawn, no worries.
Really? Paul and I had some discussion about this some
time ago in the article I cited above.
We finally resolved to talk about load-dump in the automotive
parlance where it's assumed that the battery is not present
to keep the bus voltage down.
Here I did a "worst case" analysis that challenged Paul's
assertions that Transorbs could be depended on to stand off
the effects of load-dumps and ov conditions and (gasp), crowbar
the breaker open. The energy numbers didn't add up as described
in the article. A concept you've also embraced above. If it's
okay to depend on a Transorb to open an array breakers in case of
an OV event, what's wrong with opening THE field breaker for
precisely the same reason?
I'll agree that as long as a good battery stays on line
the overall risks to the rest of the system (ESPECIALLY when
qualified to DO160 Power Input testing) is quite low. But
Paul was intent upon stacking battery disconnect on the
equation. Similarly, I was insistent on considering the overworked
battery.
So it finally boiled down as to which breaker(s) you were
going to overload and how long you were going to wait before
the desired outcome was achieved. The use of Transorbs for
mitigating ANYTHING over a hand-full of milliseconds is
shaky. While advertised as useful in mitigating automotive
load-dump situations . . . this must be done with care and
the better solution is to trap the load-dump event off at
the source and let Transorbs do what they do best, trap
very short transients.
By endorsing the use of Transorbs downstream of a breaker, you've just
validated the crowbar OV system design. The only difference
is, you choose to overload lots of breakers by a little bit and wait
perhaps seconds for them to operate, I overload one breaker by a lot
and boot the puppy open in milliseconds. One only needs to study how
much of the alternator's excess energy is dissipated in the two events.
Crow-baring a field breaker is at most a 200 watt-second event.
Crow-baring bus breakers will be many times longer killowatt-second event
and depends on balancing the loads across the array of breakers as
described in the paper.
I have talked to Van many times. I've asked to do a weekend seminar
for their staff like I did for Lancair. I'm going to do one in their
neighborhood and HOPE some of their staff will attend. I may have to
specifically invite them and/or offer free tuition.
That is real nice of you. Why call the man ignorant? Did he NOT get all excited about
FUSES, central ground and crow bars? Really there is nothing really new under the sun
Bob. Van has common sense and an eye on the BIG PICTURE, not just the minutia of one
possible electrical problem that is not that common any more. (In the old days there
where lots of OV because the external VRs where crap.
Because he demonstrated his lack of knowledge in the discussions
I had with him. He has a superior knowledge of airframes, engines and
flight controls. It would be foolish to expect him to be equally versed
in electrics.
You've stated that you have no personal knowledge of the internal
workings of the regulator chip in an IR alternator, nor
are you privy to schematics upon which one bases a failure
mode effects analysis.
Oh Geeee Bob, I suggest you have not processed the info. I told you at least 4
times I cannot get any detailed info on the IR chip inside a ND. I got some general
sales claims about OV and Load Dump protection but nothing real technical.
Exactly! You have the same level of ignorance about
the internal regulators as I do. You're comfortable
brushing this off based on your demonstrably anecdotal
field history; I cannot recommend them precisely because
I don't have the necessary data either and I will not
base a recommendation on field history that I did not
personally put my hands on.
Again Load dump means 5-10 amps, not 30-60amps during a B-lead abortion from a crow bar.
How do you get this? If you're just done a hard start and the battery is being
re-charged, the alternator will be running at or close to full-bore. Turning the
alternator switch OFF under this condition will generate a load dump much
greater than 10 amps. This may in fact have been the conditions that prevailed
during the reported failure I cited above.
Turning the alternator off during an OV condition is guaranteed load dump
equal to or greater than the alternator's nameplate rating. A risky event
indeed.
OK Bob how much as electrons changed since 1950? My guess 1950 and 2005 electrons
are the same. I cant believe there is anything real bad about a 1950 Cessna with
the added IR alternator. We are talking about DC circuits. Bob here is your
distinguish wiring (MO) Modus Operandi:
-Central Ground (excellent idea I might add)
-B-lead fuse forward of firewall , connect to battery before buss**
-Automotive fuse block and ATQ blade fuses
-Spade connectors vs. ring
-Crow bar
**( Use of B-lead fuse vs. a panel CB sacrifices alternator control. Suggest the overstressed claim of noise be ignored and use a panel CB, especially if you use an IR alternator. I find it ironic Bobs technology is right out of an import car. Japanese car imports pioneered this approach to DC power distribution. The plastic fuse blocks are right out of a car. Bob likes, auto technology and wiring, but does not like the IR alternator for lack of control.
Well if you use a CB for the B-lead in the panel, you have control.
. . . and perhaps a great way to set the breaker on fire.
Circa 1950s Cessna (and Beech / Raytheon ) probably has crazy wily-nily grounding
schemes using multi point airframe grounds too much.
Yup, they'd like to make it better but it costs us
about $2K just to change one page of engineering
documentation not to mention costs of certification.
That's never going to get fixed.
It also probably has a big fat CB on the panel for the B-lead, which is no big deal.
Nope, production airplanes at RAC DO NOT bring the b-lead into the cockpit.
The b-lead protection has been ANL current limiters on the firewall for many years.
Click here to get a view of the firewall on a Bonanza. See all those
current limiters? They've REPLACED the b-lead breaker (amongst others) in the cockpit.
Note also the fist full of glass cartridge fuse holders just above
and to the left of the ANL patch . . . also off the panel.
As far as materials I don't think Van uses 1950 wires and connectors. I am sure his
kit uses new mil spec wires and modern crimped connection. HOW BAD COULD IT BE? I
looked at Tony Bingelis Books and than yours, Bob. Wires are wires. DC circuits are
DC circuits. We are talking about a simple DC power distribution system. You don't
know Van. It is not ignorance; he just does not give a rats ass about the smallest of
electrical details that will affect .0001% of his builders. If it gets the job done,
than it is good enough.
Van's choices of materials are not and have never been a problem
with me, why do you raise the question now? Why include a listing
of my noteworthy contributions? How does anything offered by Tony
bear on this discussion? I've often written that if folks are happy
with the way their antique certified ship's electrical system performs,
then it's perfectly okay to lift that system out and drop it into their
new RV - which is exactly what the majority of OBAM aircraft builders
are doing.
If that's a builder's design goal the Van kit (with admittedly
suitable materials) is the way to go. The only later-day contribution
offered in Van's plans for appliances is incorporation of a modern,
internally regulated alternator . . . which the builder MUST
control with a b-lead breaker (also part of the kit). We
were never discussing Van's or anyone else's recommendations
of installation materials.
None of this contributes to the discussion at hand . . .
>Except that we CAN design an electrical system that will
>NEVER be a link in the chain of events contributing to
>a catastrophe.
Can never say NEVER in an airplane Bob. That is the answer I expect from an
electrical engineer. You can try and believe you have designed the perfect system,
but there is nothing perfect. A little piece of foam destroyed the space shuttle.
Apollo 13 went boom from a faulty heater.
Forgive me, 10-to-the-minus-6 probability or better
is "never" in FAA parlance. Given that we don't have
10-to-the-minus-anything data, the word "never" was
inappropriate. Further, I've never suggested that any system
philosophy was "perfect" only "failure tolerant".
Voltage regulators are not the issue. Alternators you
cannot control are the issue.
Oh Bob Bob Bob, you love to sensationalize, you CAN control an IR alternator: First)
Pull the B-lead CB or Second) . . .
Assuming the breaker's internal performance will break the
arc and/or the breaker's enclosure will contain the fire.
Turn the master switch OFF. You have isolated the alternator. I understand what
you are saying, but statistically you are myopic. The pilot is the key to safety
not the engineer.
???? Gee, does this mean I can do anything in the way of
system design and architecture as long as I put the right
words into the POH under EMERGENCY PROECEDURES?
Even a crap electrical system is the most reliable thing on a small plane. Loss
of an alternator should not be fatal. What is a pilot doing flying IMC of mountains
at night.
I don't do it . . . but my boss says lots of our customers do
it. I have dozens of hi-performance OBAM aircraft owners
who do it too . . . and I hope with very simple paragraphs
under EMERGENCY PROCEDURES that prevent any incident from
propagating into an unmanageable event.
You are a typical design engineer that feels you can control everything.
You cite facts not in evidence. I take cues from my
customers and supervisors to achieve their vision for how
the products I design should perform. It's my duty as an
engineer to either meet all goals as requested or give good
reasons by FMEA (or limits to available technology) as to
why they cannot be met. Even AFTER the goals are met, they
may never see the light of production line due to costs,
volume, weight or customer acceptance. This has nothing to
do with your perceptions of my FEELINGS as an engineer,
typical or otherwise. If this working philosophy departs from
your perceptions of a "typical design engineer" then so be it.
I readily confess a desire not to be "typical" in any regard.
Thank you for the compliment.
I understand your engineer mentality. I don't care about a crow bar; I care
about living. Don't over estimate the significance of this one item to miss the
big picture. By adding this protection device you introduced another failure
point. Does it justify adding it?
You betcha, as long as adding that component drives
probably of comfortable termination of flight UP and not DOWN.
The design goal was to keep the worst the alternator can
do from propagating out onto the system and without adding new
pilot responsibilities. This is what my bosses and the FAA would
require me to do. One excellent way to get re-assigned would be
to suggest a system that requires a pilot to perceive, react and
effect a generator shutdown for the OV condition no matter how
probable that condition may be. The assumption for the OBAM aircraft
community has always been that there will a simple, Plan-B to implement
and allow comfortable termination of flight.
Don't scare people with sensationalized rhetoric. That is a cheap game plan for
someone who likes to be thought of as a benevolent impartial teacher and engineer.
No rocket science, just basic DC circuits 101. How can you not understand that?
It is not as complicated as you like people to believe. EVERY ONE KNOWS BOB CAN'T
RECOMMEND THE ND ALTERNATOR. OK. YOU WIN, I AM WRONG.
I've sensationalized nothing. I've tried to deduce a means
by which the design goal of incorporating IR alternators
into light aircraft can be accomplished under the SAME design
goals we're familiar with and have been flying for years.
I avoided the subject for years in the first 7-8 revisions
to the 'Connection. In deference to CUSTOMER demand, I
attempted to craft a satisfactory incorporation of
the IR alternator while staying within the design goals
of past designs. Except for (1) a shortfall in contactor
performance to survive and (2) vulnerabilities in the
alternator's ability to stand-off it's own load-dump
events, the experiment almost succeeded.
So, bloody but not bowed, I've retracted my recommendations.
However, you've stepped forward with recommendations of your
own which may be accomplished if one is willing to embrace your
design goals.
You've accurately described your architecture and operating
requirements and I would ENCOURAGE any builder reading
this exchange to adopt your suggestions if they are
consistent with their personal design goals.
This doesn't change my obligation to suggest that your philosophy
as I understand it has forces the following considerations:
(1) a marked shift from past philosophies concerning alternator
control and does not accommodate the need for pre-flight
testing of auxiliary or standby alternators. This happens
when the pilot is not offered absolute, any-time, any-conditions,
risk-free CONTROL of the airplane's electrical sources.
(2) there are considerations to be explored and resolved
- smoke from circuit breaker plastic is not from
Marlboro Country.
(3) Further, the builder should provide the same quality
of warning for high voltage as for low voltage. I prefer
to automatically sense and control an OV event.
(4) Then consider the new para . . . (oops) design goal that
puts the pilot in the loop to provide timely reaction
to the OV event.
(5) finally, this design philosophy is not friendly to the idea of keeping
the most antagonistic wire in the airplane out of the cockpit -
a design goal adopted by many type certificated aircraft.
Thank you for the gray-matter exercise. It's been fun except for your
use of words that appear intended to demean or injure. I'll leave it for
future readers of this exchange to decide for themselves as to which
of us is most disposed to the use antagonistic, sensationalistic speech.
Bob . . .
------------
An Email Exchange on the AeroElectric-List from 2004
------------
At 10:34 PM 1/1/2006 -0800, you wrote:
--> AeroElectric-List message posted by:
>From: "Robert L. Nuckolls, III"
>B: The only concerns I might have for alternator "stress" at low rpm is
>cooling. This is hard to achieve on a Lycoming installation when you leave
>the small pulley in place. Even so, terms like "low rpm", "very high draw",
>"extra strain", "reducing total load", and "brief" are all non-quantified
>terms having no value for advancing either understanding or increasing
>service life of the alternator.
G: I think it is hilarious that you are NOW writing Niagara Airparts, aka
Canadian Aero Manufacturing, to ask what they meant in their alternator
instructions. Its great you are asking, but you already have run your mouth.
You said its wrong and gives no insight or understanding into the physics.
Why start asking questions now? You attacked Vans, Blue Mountain
Avionics and Skytec with out asking for their opinion or clarification first.
B: I'm pleased that you're enjoying it sir but I wonder if you
truly understand the reason for the inquiry . . . and please
note that the quotation of me was taken from something other
than my letter to Niagara.
I did talk to Van's . . . they could not offer any clarification.
I never attacked Blue Mountain. Greg attacked me with words like:
"I've seen so much truly atrocious work, much of it per Bob's book".
When I asked him for clarification, over the course of several
e-mails he refused to answer a single, direct and politely
crafted question.
Words SHOULD mean things. So one presumes that when the phrases
I cited above were offered to expand a customer's understanding
of the product offered, it's reasonable to ask for definitions.
This is especially important when the words seem to imply
weakness or fragility when compared to similar products.
For example, suppose I offered you a new kit aircraft where I
suggested: "Do not operate too slow lest you fall out of the sky,
do not apply full control movements too fast lest you break something."
Would you not be curious as to the numbers describing "too slow"
and "too fast."
I'm aware of no other manufacturer who has found value in suggesting
that their alternator be "pampered" in any way. The astute consumer
would want to know what's different between Niagara's products
their competition . . . and further, what value the customer might
get from observing the cautions.
I'll make a wager with you. I'm willing to bet that the folks at
Niagara have no basis in physics for the paragraph under discussion.
We'll further deduce that putting such words in their product
literature unfairly suggests a deficiency in their product's
capabilities. We'll find that eliminating those words will make
their customers feel better about the product and offer no real
risks for making the decision to buy the product. What's your
wager? What's your hypothesis as to the answers to my questions?
I'll suggest that a discussion of alternator physics will be a lot
more fun than trying to paint me as the dishonorable individual you
seem to perceive.
G: You are entitled to your opinion and not lacking them by the way, but why
care what Niagara says now; it makes no difference, you are right, they are
wrong. Your ability to write is far superior to anyone, so it is understandable
that it does not meet your standards. Why embarrass them with their
ignorance.
B: I offered nothing in the way of an opinion to Niagra. I simply
introduced myself and inquired as to further definition of their
words. It's not polite to start a conversation with an argument
when it's possible that they will come forward with perfectly
good reasons for their words. If they have good reasons, I'll
be delighted to understand the basis on which they're offered.
That's how one learns new things. Wouldn't you agree? Are you
not equally interested in their answer? Wouldn't it be really
cool if I win my wager and Niagara's products can shed
an unfair suggestion of reduced value?
>B: By way of introduction, I'm currently an electrical engineer
>for Raytheon Aircraft (Beech) in Wichita, KS.
G: Bob, you are not an engineer. You need to go to school and have a degree to
be an engineer. I don't care what your title is at Raytheon. You are not an
engineer and never will be. You are no doubt an excellent technician but you
are no engineer. It is like calling a garbage collector a sanitation engineer,
the word engineer is there, but the can-thrower is no more an engineer than
you are a BSEE, MSEE or Ph.D EE. I dont care how well you work an
oscilloscope or solder iron that is not engineering.
B: Please don't toss the ol' sop out about degrees.
I've worked with many well degreed folks who cannot do
1/10th of what I do. A degree is simply a demonstration of
your ability to learn and says nothing about your ability or
willingness to apply what you've learned. I was blessed with many
opportunities to learn on my job. You know nothing about how
well I do anything and what my employers choose to call me and how
they assign my tasks is their business.
I've worked with some stellar folks and with some duds both
in management and engineering. So what's new? Are you suggesting
that ANY "real" EE could step in an take my job? Some could,
most could not.
G: The title engineer is one of the most miss used and abused terms. The
American Medical Board would not allow anyone to put up a shingle and
call himself or herself a Medical Doctor, MD. However in this country
anyone can call themselves an engineer.
As a licensed PE, with two engineering degrees I am offended by your
assertion you're an engineer, especially after your comments of contempt
and low esteem towards engineers.
B: Only some engineers. Nature has provided us with the bell curve:
a graphical presentation of gaussian distribution of traits in
large populations. In the population of engineers, there are some
that are very good and place high on the ordinate for capability
but low in numbers compared to the whole. But for every exceptional
individual, there must be a counter balancing individual who
may wear the mantle but has never achieved stature in their
craft. These too are small in number. Most are scattered along the
curve in accordance with their skills, willingness to learn and
opportunities to exercise their craft. I shouldn't have to explain
that to an educated person but meanings you attribute to my words
suggest that you don't understand this simple truth.
G: Bob you said you would rather hire a person from a community college
who knows his way around a workbench than an engineer. First I seriously
doubt you are in charge of hiring engineers.
B: I have said no such thing. I've made note of the fact that
my JC techs could all hit the ground running and the brightest
and most motivated became invaluable employees . . . some went
on to get higher degrees and are still invaluable employees. But
as noted above, a degree does not an invaluable employee make.
All of us have to perform in the marketplace and a degree guarantees
nothing.
G: Second your ignorance is common of people who dont know the body of knowledge
which encompasses engineering. You're like Cliff Calvin, the Postman on Cheers.
You know a few facts and throw around words with out understanding, like failure
mode analysis to impresses someone. LETS SEE YOUR FMA ANALYSIS. LETS SEE YOUR
DATA. What no data?
B: Hmmm . . . first I'm compared with Fox News and now Cheers.
I don't watch either. In fact I watch very little television.
Therefore I'm at a loss to evaluate your similes.
George, George . . . you claim to know so much about me
but you keep offering opinions that do not agree with fact.
May I suggest some good books might prove much more useful
than television? Have you read any Thomas Sowell? Frederick Bastiat?
Thomas Paine? But don't read them if the overriding importance is
where these guys went to school. They write in simple ideas imminently
understandable and of obvious value. My goal is to think
and write like these men. What are your goals?
G: Your comment of how unnecessary math is speaks to your ignorance of
engineering. Engineers do not necessarily work on the bench. I am sure
you can regale us with stories of how incompetent engineers are and how
superior you are over those college boys.
B: Gee, I'll have to think about that . . . no, I don't have
any such stories. But I can tell you that in the aircraft business,
the vast majority of degreed engineers have become paper-pushers.
Their engineering knowledge brought with them out of school
was never given an opportunity to be exercised and grow. . . use it
or loose it. Unlike most of my contemporaries, I'm blessed with
opportunities to learn something new every day. Aviation is
singularly hard on engineers and offers only rare opportunities
to excel.
G: Dumb engineers will live with it, leaving the workbench to your Votech oscilloscope jockeys and solder iron artist. I learned how to run a scope and solder iron when I was 13 years old. It is a vocational skill not engineering Bob. Your just a little delusional.
B: The delusion is your's sir. You're welcome to come walk with me
for a week and see what I do for a living . . .
When did I ever speak to the uselessness of math? I cannot imagine
where you get these ideas. I have a half dozen computers that I regularly
program for various control tasks and analysis by calculation. I try
to keep plenty of calculators laying around so that one is always at
hand. I have one on my wrist! Now, when was the last time I was able
to make use of any technique from say, chapter 13 of my Calculus text
book? Never. That doesn't mean those disciplines are not useful to
some individuals. Every engineer I've ever worked with has confirmed
that in the hard-cold-cruel world of keeping happy customers coming back
to buy your products, they've used only a tiny fraction of that which
academia thought was important.
G: As a PE and with a MSME it is unacceptable if Raytheon capriciously calls
technical employees like yourself engineers, who do not hold a degree
from a college of engineering, accredited by ABET (American Board of
Engineering Technology).
NSPE (National Society of Professional Engineers) handles the licenser of
Professional Engineers (PE) and protects the profession from frauds, albeit
and apparently poorly. I hope the real engineers at Raytheon who hold
advanced degrees do not let technicians, such yourself hold the title of
engineer, and your letter to Niagara is just your normal smoke blowing
boastful self-importance display of grandioseness and pomposity.
Does your stupid management know you write all kinds of negative
comments about management (them) and Raytheon? I need to sell my
Raytheon stock. It is up over $40 and I bought it at $30. Knowing how
disgruntled you are with management and how Raytheon does not appreciate
you Bob, I better sell my stock right now.
B: I'd recommend that. If Raytheon would dump the aircraft albatross
the corporate stock would probably run back up to $75. Now that
the 4000 is close to certification, they'll probably continue their
exercise in self-abuse somewhat longer. But short of a big shooting
war I don't expect to see Raytheon stock do anything spectacular.
Less than 1/4th of my retirement portfolio holds Raytheon. Just
the humble opinion of an inside observer over the past 20 years.
But please don't take my word for it. I bought all of my stock
when it crashed from $75 to $18 a few years back . . . but it's been
frustratingly static for a long time. My investment advisor cousin
has suggested that I not buy any more . . . there are presently
much better places to put your money.
G: I have my sell order in for Monday morning. A thanks for the heads up on how screwed up Raytheon is. I know how you feel, you being an Eagle its hard to soar with Turkeys. Things would be so much better if you where running things I'm sure. Oh well.
Your Buddy George, CFI,II,MEI,ATP,CE500, B737, B757, B767
Happy New Years.
B: My new year is starting off very nicely thank you. I'm sorry
that your's is so burdened with unhappy thoughts borne out of
ignorance about me and what appears to be a disregard for folks
who choose to learn outside the hallowed halls of ivy. If universities
were the only source for useful knowledge, there are many stellar
minds in history that should never have achieved greatness.
I'm saddened that you do not seem to understand or appreciate
this fact.
Your buddy Bob (a get-yer-hands-dirty engineer-imposter that
draws the salary of an engineer and has
thousands of happy customers).
