Today's Message Index:
----------------------
1. 07:43 AM - Re: Alternator Field Circuit Fuse Blow (Robert L. Nuckolls, III)
2. 10:07 AM - Re: Alternator Field Circuit Fuse Blow (Valin Thorn)
3. 11:12 AM - Re: Alternator Field Circuit Fuse Blow (Robert L. Nuckolls, III)
4. 11:16 AM - Edge of the frontier . . . (Robert L. Nuckolls, III)
5. 12:53 PM - Re: Alternator Field Circuit Fuse Blow (Valin Thorn)
6. 05:55 PM - Audio Isolation Amplifier Boards (Robert L. Nuckolls, III)
7. 07:10 PM - Re: Alternator Field Circuit Fuse Blow (Robert L. Nuckolls, III)
Message 1
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Subject: | Alternator Field Circuit Fuse Blow |
At 10:39 PM 12/7/2016, you wrote:
>Thanks Bob! I'll coordinate with B & C. We have two L3RC-28 Linear
>Regulators (flight and spare on shelf) -- so we'll send them both in
>for adjustment, one at a time so the airplane stays in service.
Good lick . . .
>
>Our fuses are crew accessible in flight. The tray pulls out from
>the right side of the panel with all the fuse blocks facing the
>pilot. The Primary Alternator Field fuse is the first one. So,
>we'll go ahead and stay with the fuse unless there's another reason
>to go CB. I can't find a good photo to show how it is set
>up. These two photos should provide an idea. See the face plate
>with a little pull ring on the right side? That's the fuse tray
>face plate, a two foot long fuse tray slides out from there. The
>second photo shows the fuse tray.
You guys do good work. There's an aura of
meticulous craftsmanship here. But I'm
a little disappointed that you spent so
much $time$ on the installation of components
with a vanishingly small chance of offering
any in-flight utility.
I would caution that fiddling with fuses,
breakers, or any other failure in flight
is a potential prelude for a bad day in
the cockpit.
When something quits working, it is either
(1) REALLY necessary for comfortable
termination of flight or (2) no big deal.
If the appliance falls in category (1)
you need a backup for it . . . a Plan B.
All appliances in the airplane have MANY
ways to stop working that DO NOT operate
the circuit protection. FBO shops are
populated with airplanes having broke
gizmos, most of which did not pop a breaker
-and- even if they did, resetting the breaker
would not return the appliance to service.
99.999% of all breakers/fuses in airplanes/cars/
boats/garden tractors will set there for
the lifetime of the machine never having
been called upon to do it's singular task:
keep a wire from burning.
Yet, there is a nagging urge to arrange
things with a notion that in-flight diagnosis
and failure mitigation is a good thing to
do.
I've read lots of dark-n-stormy night
stories in the journals . . . I've had
occasion to pick through the bits and pieces
of un-intended contacts with the earth.
All of the accidents I've worked on or studied
with electrical factors were absolutely
preventable by some combination of competent
processes and/or simply having a Plan-B.
That's a beautiful job on the fuse panel
no doubt deserving of honors for craftsmanship.
But my best wish for you is that when something
stops working, that fuse panel is the FURTHEST
thing from your mind while you concentrate on
a comfortable termination of flight.
Bob . . .
Message 2
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Subject: | Alternator Field Circuit Fuse Blow |
Thanks Bob. The entire interior of our Legacy is our own design and build
with the exception of the avionics and joy stick mechanisms. It took many
years of weekends. The instrument panel design and layout is ours but the
fine work on the instrument panel's component installation, wiring and fuse
tray was performed by Andre Todd at Aerotronics in Montana.
Yes, I agree with your philosophy regarding resetting a tripped CB or fuse
in flight. Even our nuisance trips of the field fuse weren't corrected
until on the ground. Even though we built an EAB airplane, we figure
there's a lot of wisdom in the FAR certification regulations and always
tried to align with them. That's why we made the fuses accessible in flight
and carry extra fuses with us in flight.
"You guys do good work. There's an aura of meticulous craftsmanship here.
But I'm a little disappointed that you spent so much $time$ on the
installation of components with a vanishingly small chance of offering any
in-flight utility."
Not sure which low utility components you're referring to.? Maybe the
airplane logo that lights up is one? We certainly did that in part because
we think it's a cool little feature. It may not be clear that it lights up
in a color to correspond to the caution and warning status - blue when no
issues, yellow for cautions and red for warnings. The Garmin G3X Touch
avionics systems will note on the screen when there's something out of
limits - but, it's just a small little block of words on the PFD that are
easy to miss. When the airplane logo changes color, one definitely can't
miss it. We've actually been very happy with this feature. Other than
that, our design requirements were for an IFR capable aircraft (no FIKI)
with appropriate fault tolerance for critical functions.
Thanks again for all you help! I'm about to call TJ at B &C to setup the LR
adjustment.
Valin
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Robert L.
Nuckolls, III
Sent: Thursday, December 8, 2016 8:42 AM
Subject: RE: AeroElectric-List: Alternator Field Circuit Fuse Blow
At 10:39 PM 12/7/2016, you wrote:
Thanks Bob! I'll coordinate with B & C. We have two L3RC-28 Linear
Regulators (flight and spare on shelf) -- so we'll send them both in for
adjustment, one at a time so the airplane stays in service.
Good lick . . .
Our fuses are crew accessible in flight. The tray pulls out from the right
side of the panel with all the fuse blocks facing the pilot. The Primary
Alternator Field fuse is the first one. So, we'll go ahead and stay with
the fuse unless there's another reason to go CB. I can't find a good photo
to show how it is set up. These two photos should provide an idea. See the
face plate with a little pull ring on the right side? That's the fuse tray
face plate, a two foot long fuse tray slides out from there. The second
photo shows the fuse tray.
You guys do good work. There's an aura of
meticulous craftsmanship here. But I'm
a little disappointed that you spent so
much $time$ on the installation of components
with a vanishingly small chance of offering
any in-flight utility.
I would caution that fiddling with fuses,
breakers, or any other failure in flight
is a potential prelude for a bad day in
the cockpit.
When something quits working, it is either
(1) REALLY necessary for comfortable
termination of flight or (2) no big deal.
If the appliance falls in category (1)
you need a backup for it . . . a Plan B.
All appliances in the airplane have MANY
ways to stop working that DO NOT operate
the circuit protection. FBO shops are
populated with airplanes having broke
gizmos, most of which did not pop a breaker
-and- even if they did, resetting the breaker
would not return the appliance to service.
99.999% of all breakers/fuses in airplanes/cars/
boats/garden tractors will set there for
the lifetime of the machine never having
been called upon to do it's singular task:
keep a wire from burning.
Yet, there is a nagging urge to arrange
things with a notion that in-flight diagnosis
and failure mitigation is a good thing to
do.
I've read lots of dark-n-stormy night
stories in the journals . . . I've had
occasion to pick through the bits and pieces
of un-intended contacts with the earth.
All of the accidents I've worked on or studied
with electrical factors were absolutely
preventable by some combination of competent
processes and/or simply having a Plan-B.
That's a beautiful job on the fuse panel
no doubt deserving of honors for craftsmanship.
But my best wish for you is that when something
stops working, that fuse panel is the FURTHEST
thing from your mind while you concentrate on
a comfortable termination of flight.
Bob . . .
Message 3
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Subject: | Alternator Field Circuit Fuse Blow |
>Even though we built an EAB airplane, we figure
>there=92s a lot of wisdom in the FAR certification
>regulations and always tried to align with
>them. That=92s why we made the fuses accessible
>in flight and carry extra fuses with us in flight.
Then you've misread the FARs.
Quoting from Part 23 . . .
---------------------------------
Sec. 23.1357 Circuit protective devices.
(a) Protective devices, such as fuses or circuit breakers, must be
installed in all electrical circuits other than--
(1) Main circuits of starter motors used during starting only; and
(2) Circuits in which no hazard is presented by their omission.
(b) A protective device for a circuit essential to flight safety may not be
used to protect any other circuit.
(c) Each resettable circuit protective device ("trip free" device in which
the tripping mechanism cannot be overridden by the operating control) must
be
designed so that--
(1) A manual operation is required to restore service after tripping; and
(2) If an overload or circuit fault exists, the device will open the
circuit regardless of the position of the operating control.
(d) If the ability to reset a circuit breaker or replace a fuse is
essential to safety in flight, that circuit breaker or fuse must be so
located and identified that it can be readily reset or replaced in flight.
(e) For fuses identified as replaceable in flight--
(1) There must be one spare of each rating or 50 percent spare fuses of
each rating, whichever is greater; and
(2) The spare fuse(s) must be readily accessible to any required pilot.
-------------------------
Okay, name any appliance in your project wherein
failure of that device puts the outcome of your
flight in peril. Assuming you have any such
appliance, then what is your Plan B for dealing
with the failure of that device when it DOESN'T
pop a fuse?
Given that there are dozens of ways in which an
appliance of any criticality can fail that doesn't
pop a breaker/fuse. If the device is critical to
comfortable termination of flight, then you're
advised to have a Plan B for dealing with its
failure.
It follows then that the artfully crafted aircraft
will have NO SINGLE ELECTRICAL APPLIANCE where
failure to function puts the airplane at risk. Hence
making circuit protection for that (or any other)
appliance crew accessible serves no purpose.
>=93You guys do good work. There's an aura of
>meticulous craftsmanship here. But I'm a little
>disappointed that you spent so much $time$ on
>the installation of components with a
>vanishingly small chance of offering any in-flight utility.=94
>
>Not sure which low utility components you=92re referring to=85?
The fuse panel . . .
Bob . . .
Message 4
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Subject: | Edge of the frontier . . . |
Electric-Flight Record Heralds New Era Of Aviation
Walter Extra Sets Record For Time To Climb To 3,000 Meters
http://tinyurl.com/jlynhwm
Walter Extra, the famous aerobatics pilot behind the Extra series of
aerobatic planes, has set an FAI world record in the new field of
Electric-powered planes.
[]
Launching from Schwarze Heide Airport near Dinslaken, Germany, on
November 25, 2016 he flew a unique, battery-powered plane and climbed
to 3,000m (approx. 9,842 feet) in a time of 4mins 22 seconds.
In doing so, he broke the FAI world record for electric-powered
planes that weigh between 500kg to 1,000kg (approx. 1,100 to 2,200 pounds).
Remarkably the plane, an Extra 330LE, only made its maiden flight on
June 24 of this year.
That first flight was called a "technical milestone" by Siemens, the
company behind the technology that powers the electric plane. "This
day will change aviation," Frank Anton, head of eAircraft at Siemens,
said at the time. "This is the first time that an electric aircraft
in the quarter-megawatt performance class has flown."
Siemens developed a new type of electric motor that weighs only 50kg
(110 pounds) but delivers a continuous output of 260 kilowatts
(approx. 230 horsepower) to power the Extra aerobatic plane. That is
five times more than previous comparable systems.
[]
The new system means that hybrid-electric planes with four or more
seats will now be possible.
Flying the plane on its maiden flight and for the record was Walter
Extra. An award-winning aerobatic pilot and chief designer and
founder of Extra Flugzeugbau, a manufacturer of aerobatic aircraft,
Extra gave his name to one of the most popular aerobatics aircraft in
the sport. "I pour my heart, mind and soul into ensuring that each
aircraft carrying my name is the very best that it can be," he has said.
The development, initial flights and new world record point the way
to an electric-powered future for some aircraft. The battery
technology behind the Extra 330LE is scalable, and some industry
figures expect to see electric-powered passenger aircraft carrying up
to 100 people on short-haul routes of up to 1,000km (540nm) by 2030.
In the air and without engine noise the experience is "almost silent"
Extra said.
Siemens said that they had partnered with Extra Flugzeugbau because
aerobatics planes are "particularly well suited" to taking components
to their limit, "testing them and enhancing their design".
The world record belongs to the group of Electric records for Powered
Airplanes with a take-off weight of 500kg to 1,000kg.
(Source: FAI news release. Images provided by Siemens. Top: Frank
Anton (right), who heads eAircraft within the next47 startup unit,
congratulates pilot Walter Extra, who broke the world record in
ascent on November 25. Bottom: Aircraft on record-breaking flight
Bob . . .
Message 5
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Subject: | Alternator Field Circuit Fuse Blow |
Yes, the key phrase is, ".essential to safety in flight.". That phrase
leaves things open to various interpretations.
In my work we'd try and establish a more objective, measurable safety
criteria to compare designs against. We would follow statements like
"essential for safety in flight" with criteria of minimum levels of risk as
broad as "Loss of Crew" and "Loss of Vehicle" and then break these down into
component allocations to subsystems. Then we'd perform probabilistic risk
assessments throughout the design cycles to evaluate if those risk targets
were achievable with the vehicle's design. So this would at least create
the illusion of some objective measure. But really, it was most useful to
help see the elements in the designs that were the biggest influence in
risks/safety. Could really never believe the numbers were accurate in an
absolute measure.
With that said, yes, all the components/appliances in our aircraft's
electrical system that are critical to some flight phases have redundancy or
operational mitigations that help make an good argument that none of them
are essential to safety of flight. The failure of each one, though, likely
results in some incremental increase in risks. Does it push it past the
"essential" criteria? Is a 25% increase in risk make a function essential
or is it 50% -- the FAA doesn't get that specific. And, it depends on
what's going on during the flight when it occurs. If one's on a precision
instrument approach in crummy weather, the probability of a successful
approach and landing is higher with all normal systems available and
operating. If I felt like I really needed a function/component for what
was going on in a flight, I'd probably try and replace a blown fuse once in
flight.
So, I agree with you that a strong case can be made for not requiring
accessibility in flight for CBs and fuses. I think this design decision was
probably influenced by knowing that CBs are usually accessible and in taking
the unusual aviation approach of using fuses, I wanted to at least preserve
that aspect. It sure would have been easier to mount the fuse blocks on the
avionics shelf than to make a deployable tray!
Thanks for your penetrating discussion on this!
Valin
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Robert L.
Nuckolls, III
Sent: Thursday, December 8, 2016 12:11 PM
Subject: RE: AeroElectric-List: Alternator Field Circuit Fuse Blow
Even though we built an EAB airplane, we figure there's a lot of wisdom in
the FAR certification regulations and always tried to align with them.
That's why we made the fuses accessible in flight and carry extra fuses with
us in flight.
Then you've misread the FARs.
Quoting from Part 23 . . .
---------------------------------
Sec. 23.1357 Circuit protective devices.
(a) Protective devices, such as fuses or circuit breakers, must be
installed in all electrical circuits other than--
(1) Main circuits of starter motors used during starting only; and
(2) Circuits in which no hazard is presented by their omission.
(b) A protective device for a circuit essential to flight safety may not be
used to protect any other circuit.
(c) Each resettable circuit protective device ("trip free" device in which
the tripping mechanism cannot be overridden by the operating control) must
be
designed so that--
(1) A manual operation is required to restore service after tripping; and
(2) If an overload or circuit fault exists, the device will open the
circuit regardless of the position of the operating control.
(d) If the ability to reset a circuit breaker or replace a fuse is
essential to safety in flight, that circuit breaker or fuse must be so
located and identified that it can be readily reset or replaced in flight.
(e) For fuses identified as replaceable in flight--
(1) There must be one spare of each rating or 50 percent spare fuses of
each rating, whichever is greater; and
(2) The spare fuse(s) must be readily accessible to any required pilot.
-------------------------
Okay, name any appliance in your project wherein
failure of that device puts the outcome of your
flight in peril. Assuming you have any such
appliance, then what is your Plan B for dealing
with the failure of that device when it DOESN'T
pop a fuse?
Given that there are dozens of ways in which an
appliance of any criticality can fail that doesn't
pop a breaker/fuse. If the device is critical to
comfortable termination of flight, then you're
advised to have a Plan B for dealing with its
failure.
It follows then that the artfully crafted aircraft
will have NO SINGLE ELECTRICAL APPLIANCE where
failure to function puts the airplane at risk. Hence
making circuit protection for that (or any other)
appliance crew accessible serves no purpose.
"You guys do good work. There's an aura of meticulous craftsmanship here.
But I'm a little disappointed that you spent so much $time$ on the
installation of components with a vanishingly small chance of offering any
in-flight utility."
Not sure which low utility components you're referring to.?
The fuse panel . . .
Bob . . .
Message 6
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Subject: | Audio Isolation Amplifier Boards |
I've had a number of folks express and interst in
acquiring the boards to the DIY audio Isolation
amplifier.
Interested purchases can be made from our
website at:
http://tinyurl.com/cgr42l5
Put your order details in the Commends/Special Rquests
box at the bottom of the form. The boards are $22 ea
plus first class postage of $2.25
I'll plan on ordering boards on Monday . . .
Assembly instructions for this project are available
at:
http://tinyurl.com/ngoo6hc
Emacs!
Perhaps the better term is 'unpopulated'. It looks
like this when you're done.
Emacs!
Bob . . .
No virus found in this message.
Checked by AVG - <http://www.avg.com>www.avg.com
Bob . . .
Message 7
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Subject: | Alternator Field Circuit Fuse Blow |
With that said, yes, all the components/appliances in our aircraft's
electrical system that are critical to some flight phases have
redundancy or operational mitigations that help make an good argument
that none of them are essential to safety of flight. The failure of
each one, though, likely results in some incremental increase in risks.
What is the probability of loss for primary system
and it's Plan-B alternative in any single tank of fuel?
FMEA doesn't deal with increments . . . you either got it or
you don't.
Does it push it past the "essential" criteria? Is a 25% increase in
risk make a function essential or is it 50% -- the FAA doesn't get
that specific. And, it depends on what's going on during the flight
when it occurs. If one's on a precision instrument approach in
crummy weather, the probability of a successful approach and landing
is higher with all normal systems available and operating. If I
felt like I really needed a function/component for what was going on
in a flight, I'd probably try and replace a blown fuse once in flight.
FMEA doesn't care about probabilities and flight conditions are
irrelevant. If you have any devic ever critical to comfortable
completion of flight, then you're well advised to have
a back-up for it. In 850+ hours of flying rental airplanes,
I've NEVER perceived an elevated level of risk for not
having dug through the maintenance logs of the machines
I've rented . . . because I was prepared to continue
flight to airport of intended destination with a completely
dark panel if necessary . . . not searching for the nearest
piece of smooth pavement with a 200psi pucker-factor.
The foundation on which all the z-figures are crafted
encourages every builder to establish their own minimum
equipment list for the most demanding use of the airplane.
Then conduct an FMEA while avoiding worrisome and largely
irrelevant reliability studies . . . assume that every
piece of stuff you bolt to the airplane WILL fail at
some point in time . . . then DESIGN IN failure tolerance.
So, I agree with you that a strong case can be made for not requiring
accessibility in flight for CBs and fuses. I think this design
decision was probably influenced by knowing that CBs are usually
accessible and in taking the unusual aviation approach of using fuses.
But they are NOT all accessible. There are breakers
and fuses all over biz jets that crew cannot reach.
Heavy iron pilots are generally not allowed to reset
ANY breaker (rarely allowed a single reset on some systems)
but the foundation for EVERY system powered
by ANY breaker stands on a Plan-B.
It sure would have been easier to mount the fuse blocks on the
avionics shelf than to make a deployable tray!
My point exactly and a philosophy I have taught for decades.
In dozens of similar discussions dating back to the AVSIG forum on
Compuserve I have encouraged builders to craft a FAILURE
TOLERANT airplane wherein no single appliance can deprive
you of a comfortable termination of flight. The way I
used rental aircraft (day/night VFR with occasional punch
through for VFR over the top) this compliment of back-ups
would let me fly with confidence whether the panel was lit
up or not http://tinyurl.com/zqb4f3q
While I was flying off a little airport Dee and I owned about
1989, I crafted some GPS aided approaches to our little chunk
of asphalt using dual GPS315 handhelds. I demonstrated an ability
to reliably acquire the approach environment under circling
minimums . . . with radios totaling $300 and carried in my
flight bag. It required preparation and planning with understanding
of limits . . . but it wasn't difficult. Designing a
failure tolerant electrical and instrumentation system isn't
difficult either . . . made easier still when panel space
used by breakers/fuses is freed up for electro-whizzies that
DO something useful.
Bob . . .
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