Today's Message Index:
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1. 06:20 AM - Re: Off topic - 737 runs out of battery power ()
2. 06:46 AM - Re: Re: Off topic - 737 runs out of battery power (BobsV35B@aol.com)
3. 08:13 AM - Re: Re: Off topic - 737 runs out of battery power (Peter Hudes)
4. 08:18 AM - Re: Dynon EFIS & EMS power on the main bus (Robert L. Nuckolls, III)
5. 08:18 AM - navaid ap1 autopilot (Bill)
6. 12:16 PM - SD-8 self excitation (Etienne Phillips)
7. 12:43 PM - Re: Duracell Leaking Batteries (Glen Matejcek)
8. 02:41 PM - Re: SD-8 self excitation (Robert L. Nuckolls, III)
9. 06:37 PM - Re: Re: Duracell Leaking Batteries (jerb)
10. 07:12 PM - Re: Re: Duracell Leaking Batteries (Joemotis@aol.com)
Message 1
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Subject: | Re: Off topic - 737 runs out of battery power |
I fly the B757/B767 now, but I'm typed on the B737. I flew it for 6 years.
I also was an instructor on the B757-400. This INFO 100% off the top
of my head and should NOT be used for training or operation of a Boeing
Jet. (my lawyer would be happy.)
Boeing has very similar electrical architecture between models. I don't
have time to read the report, but I can almost certainly say what can
(and likely) happen.
The battery switch got into the position that turns the battery chargers OFF.
Battery power is critical even with all 2, 3 or 4 generators on line. On a
Boeing twin engine you can have up to 4 Gens, two engine, APU and
optional hyd motor driven gen (HMDG). The battery drives some items in
parallel or is the only source of power to others. It can cause loss of some
systems and have "unintended conciquences". It's indeed the last chance
power with out Gen power, as you say for 30 min. (Some have optional 60
or 90 min battery power.)
There is a battery switch that goes in AUTO position (or BAT) at the
start of the day. That is where it belongs and NEVER is moved in normal
operations. The other normal position is OFF, used at the end of the day
when parked overnight, some times not even than. If you left it off you
would know it and not be able to start the plane. However there are other
positions. One of these positions overrides the battery chargers (only
used for non normal events or maintence). You can put it in that
non normal postion after start with effort, but you would NEVER do that,
unless directed by a check list; you should know you did it. The issue
is accidental (brain dead) movement of the BAT switch to over ride the
battery chargers. [1]
It is VERY subtle to turn the battery chargers off in flight and the pilots
might not notice if they're not paying attention, could and has happened.
The only real in indication is an EICAS message. [2] (see B737 warning
system below) The level of the message is just advisory on the B757/767
and 747-400. Advisory is a white text message with an annunciation light,
but it does not make the bells and whistles go off.
******
So if you accidentally put the BAT in over ride and leave it there, you can
drain the batteries in flight with the Gens on line! NOTE: there is no reason
to turn the BAT to that position after its put in AUTO. It has to be in AUTO
or BAT to start the plane, so you would have to do a second (improper) step
to configure the switch.
******
So say the pilot accidentally turned the battery chargers OFF for some
reason. (This switch is not easily mistaken and requires a pull twist or
guard moved.) So the batteries keep doing thier thing, driving what they
need to, even while the Gens are all on line. When the battiers die all kinds
of weird stuff happens and the plane can be in serious dodo. The engines
will continue to run because they have continuous ignition (of jet engine
principles) and mechanical fuel pumps. Hydraulics will work, like flight
controls but you may have gear extension issues. [3]
The bottom line is the airplane assumes that during pref light the pilots
put all the switches in the proper position. There is no way an aircraft can
account for all human factors. That is why the crews are well trained. I go
through recurrance evey 6 months and have engine failures, fires,
decompression, single engine ILS to mins and every electrical, pneumatic
and hydraulic failure the sadistic instructor can think of. We use check list
and two crew cross check and standard procedures. That is why we get
paid the big bucks, to put switches in the right position.
Long story short this has happend before (one time on a B747-400 with
Asian airline).
[1] The batteries are not directly connected to the aircraft electrical system,
in that they are powered/chargers through battery chargers. As you may
know the primary gens are all AC. DC is from inverters.
[2] EICAS (engine indicating alert/annunciation system). The levels are
WARNING, CAUTION, ALERT and ADVISORY. They should notice it but
some times its missed. The Boeing 737 goes back to the 60's and had
it's first major upgrade in mid 80's and than later the "new gen" which
was a new wing. The cockpit got incremental upgrades in glass and EFIS,
however the EICAS system is rudimentary. In fact it is non existent. They
have the classic annunciation lights all over the panels and one "6-Pak"
master caution annunciation on the glare shield. You have to physically
look at of for the light in the panel. The later EICAS has a tube with actual
text message that often jives with the title of the check list you need to
address. SO ITS EASIER TO MISS IT ON THE B737, BUT YOU HAVE
TO REALLY NOT BE PAYING ATTENTION.
[3] Please arm chair expert save us your sanctimonious outrage how
stupid the engineers are and how you know better. You can't make a
system fool proof or take all control out of the hands of the crew. You
have to put a switch in the right position at the start of the flight and off
at the end of the day. Not every contingency or multiple failures can be
garded against. A well trained competent crew is required to fly a jet. For
example the fuel control switches even if garded can be turned off
(meaning inadvertent engine shut down). It happened once. You have to
pay attention when flying any plane but even more in a large jet. Things
happen fast. That is why I like my Cubs and RV. They have less
complication. I suggest every one strive for simplicity in their kit plane
system designs. (internally regulated alternators ROCK!@; externally
regulated alternators SUCK! LOL)
Message 2
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Subject: | Re: Off topic - 737 runs out of battery power |
Good Morning Mr Jet Pilot,
For What It Is Worth, the aircraft in question was a Boeing 757, not a 737.
Just a little bit of research could have revealed that fact
Happy Skies
Old Bob
Also rated on the 737 and 757/767 as well as many other aircraft.
In a message dated 10/28/2008 8:23:30 A.M. Central Daylight Time,
gmcjetpilot@yahoo.com writes:
I fly the B757/B767 now, but I'm typed on the B737. I flew it for 6 years.
I also was an instructor on the B757-400. This INFO 100% off the top
of my head and should NOT be used for training or operation of a Boeing
Jet. (my lawyer would be happy.)
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Message 3
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Subject: | Re: Off topic - 737 runs out of battery power |
On Oct 28, 2008, at 6:16 AM, <gmcjetpilot@yahoo.com>
<gmcjetpilot@yahoo.com> wrote:
> I fly the B757/B767 now, but I'm typed on the B737. I flew it for 6
> years.
> I also was an instructor on the B757-400.
Is this a new variant? I didn't know Boeing made a 757-400.
Pete Hudes
Message 4
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Subject: | Re: Dynon EFIS & EMS power on the main bus |
>Question: My question here is about the wiring of the Dynon EMS and EFIS
>to the main bus. They are powered up when the Master Switch grounds the
>Battery Contactor. The starter contactor is downstream of the battery
>contactor. When the starter is engaged by grounding the starter contactor
>with the ignition switch, both Dynons lost ship's power and came up on the
>backup battery. When we had tried this several times, the Dynon backup
>battery was exhausted and the Dynons simply went off. Again, the engine
>never started so all this was happening while the starter was engaged. My
>question is whether or not the Dynons should be moved to the Avionics
>bus. Yes, I have an Avionics Master and understand the concern about
>it. The functional problem is that the tachometer and oil pressure are
>displayed on the EMS and nowhere else. In the certified planes with glass
>panels that I'm familiar with, the glass panels are similarly connected to
>the Master Switch and stay on when the e!
> ngine is started. I need to be able to check oil pressure as soon as
> the engine starts.
>
>Thanks for any light you can shed on this. Next time, I'll move the fuel
>selector from the Off position!
The spirit and intent of avionics master switch
was to "protect sensitive avionics from hazardous
spikes generated during engine cranking."
In years since, it has been discovered that while
there was significant brown-out during the first
few milliseconds of starter operation similar to
that shown here:
http://www.aeroelectric.com/Pictures/Curves/99_Saturn_SL1_2.gif
there were no high-voltage excursions that could
not be easily handled by simple components in the
potential victim's power input conditioning.
Further, the industry tapped a huge experience base
by forming RTCA and inviting all interested parties
in aviation to participate in quantifying and documenting
the magnitude and type of stresses a piece of avionics
should shrug off.
Based on our current knowledge and skill in crafting
airplanes and their accessories, there is no need
for an avionics master switch to "protect" anything.
I believe you stated that all batteries involved in
your test were of questionable condition either by
reason of age or state of charge. I'll suggest
then that what you experienced was not worthy
of generating concerns. You need to repeat the
experiment with a known-good ship's battery and
fully charged stand-by batteries.
It's doubtful that anything was damaged. Everything
you observed appears to be the byproduct of soggy
batteries.
Bob . . .
Message 5
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Subject: | navaid ap1 autopilot |
Can anyone tell me if their is any source that can fix on an inop.
navaid ap 1 autopilot head? Bill S.
Message 6
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Subject: | SD-8 self excitation |
Hi Bob and everyone
Note 25 on page Z-10, mentions the work-around needed to self excite
the older SD-8 regulators. Does this imply that the new regulators
don't need this, and that the regulator will come alive as soon as
the engine starts turning?
Thanks
Etienne
Message 7
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Subject: | Re: Duracell Leaking Batteries |
Ironically, I had cause to pull one of Eric's zippy LED flashlights out of my flight
bag early this AM only to find the AA Duracells had leaked in the body of
the light. Yeachh...
Glen Matejcek
Message 8
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Subject: | Re: SD-8 self excitation |
At 09:05 PM 10/28/2008 +0200, you wrote:
><etienne.phillips@gmail.com>
>
>Hi Bob and everyone
>
>Note 25 on page Z-10, mentions the work-around needed to self excite
>the older SD-8 regulators. Does this imply that the new regulators
>don't need this, and that the regulator will come alive as soon as
>the engine starts turning?
Unknown. The change to the regulator's internal are very
simple and I would hope that B&C would consider this
an upgrade worthy of consideration . . . but unless they're
advertising the ability to come on line without battery
support, it's fair to assume that no changes have been
made to their product.
Bob . . .
Message 9
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Subject: | Re: Duracell Leaking Batteries |
The reason I posted the question is I have experienced a number of
them leaking in the last couple years, a large number of them in the
last year whereas before they we rock solid. What has changed, shift
in the magnetic field, alignment of the planets, year 2012
approaching. Sorry I have to say I just become very disappointed in
their product now.
jerb
At 02:41 PM 10/28/2008, you wrote:
><aerobubba@earthlink.net>
>
>Ironically, I had cause to pull one of Eric's zippy LED flashlights
>out of my flight bag early this AM only to find the AA Duracells had
>leaked in the body of the light. Yeachh...
>
>Glen Matejcek
>
Message 10
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Subject: | Re: Duracell Leaking Batteries |
My cheap boss bought a jumbo pack of Radio Shack Gold AA's. I loaded up my
brand new Dymo thermal label maker with 6 of them a week ago and used it a
little. Today, went to make a label and it was completely dead. Opened it up
and
every single one of them had oozed slime in my new printer. Cleaned up good
with a toothbrush and some contact cleaner. Went and bought some USA mad
Energiser Brand. We will see how that works out.
Where are Duracells made, USA or China?
Joe Motis
Do not archive
In a message dated 10/28/2008 6:39:04 P.M. Pacific Daylight Time,
ulflyer@verizon.net writes:
--> AeroElectric-List message posted by: jerb <ulflyer@verizon.net>
The reason I posted the question is I have experienced a number of
them leaking in the last couple years, a large number of them in the
last year whereas before they we rock solid. What has changed, shift
in the magnetic field, alignment of the planets, year 2012
approaching. Sorry I have to say I just become very disappointed in
their product now.
jerb
At 02:41 PM 10/28/2008, you wrote:
><aerobubba@earthlink.net>
>
>Ironically, I had cause to pull one of Eric's zippy LED flashlights
>out of my flight bag early this AM only to find the AA Duracells had
>leaked in the body of the light. Yeachh...
>
>Glen Matejcek
>
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