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rkharr

Joined: 10 Jan 2006
Posts: 12
Location: Columbia, SC

Posted: Fri Jan 31, 2014 11:53 am Post subject: Essential Bus question

My RV-6 has been flying 12 years now with an electrical system based on the Z diagrams.  Now I am assisting my wife complete her RV-7 electrical system.  She has chosen to use the VPX Pro unit and wants to incorporate a "backup" source of power for clearances, engine start, and "endurance" (if the VPX box were to quit).  

The circuit that we are considering uses a bridge diode that would allow the main battery to supplement the "backup" battery for increased endurance.   Since I have not seen this variation before, there must be a "gotcha" that I haven't found.   Attached is a picture of the basic circuit.  Any suggestions and/or comments would be appreciated.

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_________________
Ken
RV-6
South Carolina

Kellym

Joined: 10 Jan 2006
Posts: 1705
Location: Sun Lakes AZ

Posted: Fri Jan 31, 2014 6:27 pm Post subject: Essential Bus question

My first question would be why add the complexity of a second electrical 

system, when virtually all situations can be handled by either backup 

battery for EFIS, ship's battery or just plain old magnetos.



On 1/31/2014 12:53 PM, rkharr wrote:

 	  Quote: 	
		   



 My RV-6 has been flying 12 years now with an electrical system based on the Z diagrams.  Now I am assisting my wife complete her RV-7 electrical system.  She has chosen to use the VPX Pro unit and wants to incorporate a "backup" source of power for clearances, engine start, and "endurance" (if the VPX box were to quit).

 The circuit that we are considering uses a bridge diode that would allow the main battery to supplement the "backup" battery for increased endurance.   Since I have not seen this variation before, there must be a "gotcha" that I haven't found.   Attached is a picture of the basic circuit.  Any suggestions and/or comments would be appreciated.



 --------

 Ken

 RV-6

 South Carolina





 Read this topic online here:



 http://forums.matronics.com/viewtopic.php?p=417953#417953





 Attachments:



 http://forums.matronics.com//files/essential_bus_237.jpg

_________________
Kelly McMullen
A&P/IA, EAA Tech Counselor # 5286
KCHD

nuckolls.bob(at)aeroelect
Guest

Posted: Sun Feb 02, 2014 8:13 am Post subject: Essential Bus question

At 08:25 PM 1/31/2014, you wrote:




My first question would be why add the complexity of a second 

electrical system, when virtually all situations . . .



   Define "all situations" . . . the term is non-

   quantified/qualified. When we're designing a

   TC aircraft, EVERY situation needs to be articulated

   in the design documents along with the plan-B, C, . . .

   or Z that mitigates that situation. Then we have

   to go TEST every one of those plans to demonstrate

   compliance with design goals.



  . . . can be handled by either backup battery for EFIS, ship's

  battery or just plain old magnetos.



   For OBAM aircraft it's a function of design goals built upon

   the pilot's skills, maintenance protocols, airplane capabilities

   and anticipated missions. Obviously, the manner in which

   one might outfit a Kitfox can depart greatly from the

   way you would craft an LAIV-P. At the same time, the

   builder of an RV-6 in the Pacific NW (Lots of clouds

   all the time) who travels a lot might have a more

   sophisticated system than another builder who intends

   to use is LAIV only in day VMC but wants the

   speed, ability to hop the occasional mountain range

   and air conditioning.



   This litany of potential "situations" offers

   a brief peek into the value of having design

   goals synchronized to the end-use.



   Production aircraft tend to have cookie-cutter

   approaches to system architecture . . . because

   the designers can only hypothesize greatest risk

   situations for the targeted customer then address

   those hypotheses within the framework of the

   impediments to creativity imposed by the FARS.



   We on the List have a clean sheet of paper

   for the beginning of every project. The Z-figures

   are intended to offer a sort of "Cliff's Notes"

   on architectures that span the spectrum of

   possibilities. Some builders have put Z-14

   into their 2 place RV's at no small penalty

   for cost and weight . . . but find comfort

   in not having to go through the very non-

   trivial exercise of optimizing their decision.



   There ARE LAIV-P aircraft flying with one

   battery, one alternator, and backup batteries

   sprinkled over the panel and perhaps some

   more in the flight bag.



   Its unlikely that either builder has tested

   available failure response plans against his/her

   perceptions of capability in the Plan-B

   hardware.



   Given the decreasing failure rates of modern

   electro-whizzies, it's unlikely that either

   of the pilots in the last two examples will

   have a 'dark-n-stormy night' story to write

   up for Flying Magazine.

   Bob . . .

nuckolls.bob(at)aeroelect
Guest

Posted: Sun Feb 02, 2014 8:42 am Post subject: Essential Bus question

At 01:53 PM 1/31/2014, you wrote:

 	  Quote: 	
		  



My RV-6 has been flying 12 years now with an electrical system based 

on the Z diagrams.  Now I am assisting my wife complete her RV-7 

electrical system.  She has chosen to use the VPX Pro unit and wants 

to incorporate a "backup" source of power for clearances, engine 

start, and "endurance" (if the VPX box were to quit).


	


   Okay, you're plagued with the same litany of concerns

   that arise from lack of confidence in your present

   'vision' for how this system should evolve.

 	  Quote: 	
		  

The circuit that we are considering uses a bridge diode that would 

allow the main battery to supplement the "backup" battery for 

increased endurance.   Since I have not seen this variation before, 

there must be a "gotcha" that I haven't found.   Attached is a 

picture of the basic circuit.  Any suggestions and/or comments would 

be appreciated.


	


    Read through the posting I made a few minutes ago

    and then consider a list of design goals that are

    based on . . .



    (1) How will this airplane be used? Do you

    anticipate long legs of travel at night over

    unfriendly terrain?



    (2) Are you anticipating more than a tiny

    percentage of approaches to landing to be

    in IMC?



    (3) Do you plan to carry the ultimate in

    backup reliability in your flight bag?



http://tinyurl.com/d5mrjgh



    This is the stuff I recommend for folks like

    me who only rent airplanes . . . but if

    it were my airplane, those items would still

    be with me. In fact, I've not turned on a

    VOR or ADF in 15 years . . . nor have I used

    a panel mounted GPS . . . but that's another

    story.



    (4) Are your skill sets going to be honed

    to the levels necessary for low risk

    implementation of the hardware you plan to install?

    It's entirely possible to have an airplane

    decked out to the window-sills with goodies

    only to have A pilot become the weak link

    in the chain.



http://tinyurl.com/kb2zr8m



    I've flown with pilots who were quite proud

    of all those dials, switches and knobs on

    the panel who never flew more IFR than to

    keep their ticket current. The greatest

    risk for bending their airplane was not

    rooted failure of hardware.



    Keep in mind that 2x the hardware is 2x

    the probability of failure. Got some more

    batteries scattered around the airplane

    . . . guess what . . . now you're running

    a clinic for batteries upon which you believe

    you're building a 'dependable' system.



    Commodity items like batteries are like house plants.

    Just  because you have two of them does not mitigate

    the need for knowledgeable preventative

    maintenance but it DOES double the maintenance

    $time$.



    So before we spend a lot of time refining

    the work-arounds for hypothesized failures,

    let's look at the big picture and size the

    solutions to realistic risks having the

    greatest probability of presentation.



    Then you're ready to sift solutions for those

    having the lowest cost of ownership, weight

    penalties on the aircraft and taxation of

    your skill sets.

   Bob . . .

tim2542(at)sbcglobal.net
Guest

Posted: Sun Feb 02, 2014 9:32 am Post subject: Essential Bus question

I would just add a simple Brown out 7ah Alarm battery/Aux bus charged thru a Schottky diode and maybe a resistor is very simple & cheap to do. A lot of equipment now comes with multiple diode isolated power inputs making it easy. 

This allows flight plan entry and clearance requests before start up without draining the main battery,  keeps the GPS/NAV/COM and EFIS from rebooting when cranking the engine, and provides maybe 20-30 minutes of extra time to get back on the ground. 

Weight/cost is about $35 and 5 lbs. cheaper than a factory backup, which only powers one item. 

Tim

 	  Quote: 	
		   On Feb 2, 2014, at 8:39 AM, "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> wrote:

 At 01:53 PM 1/31/2014, you wrote:

> 

> 

> My RV-6 has been flying 12 years now with an electrical system based on the Z diagrams.  Now I am assisting my wife complete her RV-7 electrical system.  She has chosen to use the VPX Pro unit and wants to incorporate a "backup" source of power for clearances, engine start, and "endurance" (if the VPX box were to quit).

  Okay, you're plagued with the same litany of concerns

  that arise from lack of confidence in your present

  'vision' for how this system should evolve.

> 

> The circuit that we are considering uses a bridge diode that would allow the main battery to supplement the "backup" battery for increased endurance.   Since I have not seen this variation before, there must be a "gotcha" that I haven't found.   Attached is a picture of the basic circuit.  Any suggestions and/or comments would be appreciated.

   Read through the posting I made a few minutes ago

   and then consider a list of design goals that are

   based on . . .

   (1) How will this airplane be used? Do you

   anticipate long legs of travel at night over

   unfriendly terrain?

   (2) Are you anticipating more than a tiny

   percentage of approaches to landing to be

   in IMC?

   (3) Do you plan to carry the ultimate in

   backup reliability in your flight bag?

 http://tinyurl.com/d5mrjgh

   This is the stuff I recommend for folks like

   me who only rent airplanes . . . but if

   it were my airplane, those items would still

   be with me. In fact, I've not turned on a

   VOR or ADF in 15 years . . . nor have I used

   a panel mounted GPS . . . but that's another

   story.

   (4) Are your skill sets going to be honed

   to the levels necessary for low risk

   implementation of the hardware you plan to install?

   It's entirely possible to have an airplane

   decked out to the window-sills with goodies

   only to have A pilot become the weak link

   in the chain.

 http://tinyurl.com/kb2zr8m

   I've flown with pilots who were quite proud

   of all those dials, switches and knobs on

   the panel who never flew more IFR than to

   keep their ticket current. The greatest

   risk for bending their airplane was not

   rooted failure of hardware.

   Keep in mind that 2x the hardware is 2x

   the probability of failure. Got some more

   batteries scattered around the airplane

   . . . guess what . . . now you're running

   a clinic for batteries upon which you believe

   you're building a 'dependable' system.

   Commodity items like batteries are like house plants.

   Just  because you have two of them does not mitigate

   the need for knowledgeable preventative

   maintenance but it DOES double the maintenance

   $time$.

   So before we spend a lot of time refining

   the work-arounds for hypothesized failures,

   let's look at the big picture and size the

   solutions to realistic risks having the

   greatest probability of presentation.

   Then you're ready to sift solutions for those

   having the lowest cost of ownership, weight

   penalties on the aircraft and taxation of

   your skill sets.

  Bob . . .

nuckolls.bob(at)aeroelect
Guest

Posted: Sun Feb 02, 2014 10:47 am Post subject: Essential Bus question

At 11:31 AM 2/2/2014, you wrote:

 	  Quote: 	
		  



I would just add a simple Brown out 7ah Alarm battery/Aux bus 

charged thru a Schottky diode and maybe a resistor is very simple & 

cheap to do. A lot of equipment now comes with multiple diode 

isolated power inputs making it easy.

This allows flight plan entry and clearance requests before start up 

without draining the main battery,  keeps the GPS/NAV/COM and EFIS 

from rebooting when cranking the engine, and provides maybe 20-30 

minutes of extra time to get back on the ground.

Weight/cost is about $35 and 5 lbs. cheaper than a factory backup, 

which only powers one item.



Tim


	


    Good data points. Let us consider the premises

    underlying the evolution of Figure Z-07



http://tinyurl.com/my9u3ud



    this shows a two battery/single alternator system

    for an electrically dependent engine. This

    exercise in 'electron gazing' grew out of Fred's

    project already fitted with a EXP-Bus. I could

    see a way to accommodate Fred's initial design

    goals for two batteries with a simple mod to

    the EXP-Bus . . . but I could see an alternative

    to Z-19 evolving from the deliberations . . .

    hence Z-07.



    Off in the distance, I think I see a single-battery

    variant of this architecture but that's possible

    only after we get real energy requirements data

    . . . and further refine the operating philosophy

    for the system. Tim's words raise useful questions

    that go directly to deliberations for sizing risks

    in a single-battery design.



    Where is it written or demonstrated that having

    the ship's processors 'reboot' is a bad thing?

    Under what operating scenarios is it useful/necessary

    minimize the time between the glass being awake

    and reaching the end of the runway just prior

    to engine run-up?



    I recall some stories about the Blue-Mountain

    systems (hard drives?) taking perhaps 90

    seconds to wake up . . . but when was the

    last time you were ready to check mags less

    than, say 3-4 minutes after engine startup?



    I've reviewed as many of the airports I've

    visited that I can remember. I cannot recall

    any departure where engine run-up was accomplished

    for before the oil was warmed up a bit and I

    had taxied from parking to the run-up stand,

    certainly 4 minutes, sometimes 10. I think

    it took 15 minutes to get out of KCI once.



    . . . the check list belongs to YOU . . . you

    can adjust sequences of events to fit hardware.



    Let us consider "draining the main battery"

    for the purposes of gathering the ATIS data

    and getting a clearance delivery. Suppose the

    e-bus runs 5A and the exercise takes 3 minutes.

    12v x 5a x 60s x 3m = 10,800 watt-seconds.

    Cranking the engine 12v x 200a x 10s = 24,000

    watt-seconds. What does the battery hold?

    12v x 5a x 60s x 120m = 432,000 watt-seconds.



    Okay, you used up 34,800 watt-seconds before

    the engine was lit for 35K/432K or 8 percent

    of the battery's capacity. If you're targeting

    80% of new capacity for banishing your battery

    to kiddie-car duty, then the last flight

    will tax the battery to 10% of available

    capacity.



    The above analysis is a first order estimate

    and does not take into account vagaries of

    temperature and internal impedances of the

    battery but it's in the right church if not

    in the right pew.



    Whats is the return on investment for 5 more

    pounds of battery and two batteries to maintain

    instead of one?



    The value of this . . . or even more detailed

    analysis presumes that you KNOW what the

    drains are and what the battery's capabilities

    are after accounting for aforementioned

    vagaries AND targeted end of life decisions.

   Bob . . .

jluckey(at)pacbell.net
Guest

Posted: Sun Feb 02, 2014 2:34 pm Post subject: Essential Bus question

my comments in larger font...

-Jeff

        From: "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com>

 To: aeroelectric-list(at)matronics.com 

 Sent: Sunday, February 2, 2014 10:47 AM

 Subject: Re: Essential Bus question

 --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com (nuckolls.bob(at)aeroelectric.com)>

At 11:31 AM 2/2/2014, you wrote:

 	  Quote: 	
		   --> AeroElectric-List message posted by: Tim Andres <tim2542(at)sbcglobal.net (tim2542(at)sbcglobal.net)>

 I would just add a simple Brown out 7ah Alarm battery/Aux bus charged thru a Schottky diode and maybe a resistor is very simple & cheap to do. A lot of equipment now comes with multiple diode isolated power inputs making it easy.

 This allows flight plan entry and clearance requests before start up without draining the main battery,  keeps the GPS/NAV/COM and EFIS from rebooting when cranking the engine, and provides maybe 20-30 minutes of extra time to get back on the ground.

 Weight/cost is about $35  and 5 lbs. cheaper than a factory backup, which only powers one item.

 Tim

   Good data points. Let us consider the premises

   underlying the evolution of Figure Z-07

http://tinyurl.com/my9u3ud

   this shows a two battery/single alternator system

   for an electrically dependent engine. This

   exercise in 'electron gazing' grew out of Fred's

   project already fitted with a EXP-Bus. I could

   see a way to accommodate Fred's initial design

   goals for two batteries with a simple mod to

   the EXP-Bus . . . but I could see an alternative

   to Z-19 evolving from the deliberations . . .

   hence Z-07.

   Off in the distance, I think I see a single-battery

   variant of this architecture but that's possible

   only after we get real energy requirements data

   . . . and further refine the operating  philosophy

   for the system. Tim's words raise useful questions

   that go directly to deliberations for sizing risks

   in a single-battery design.

   Where is it written or demonstrated that having

   the ship's processors 'reboot' is a bad thing?

OK, let me write it here:

Watching the Garmin 430 in my Cherokee re-boot after engine start is very inconvenient. Is it catastrophic? No.  Are there work-arounds? Certainly.  It's just a pain in the (at)ss.  In an experimental w/ all glass, it would be even more annoying.

Now that I'm designing the electrical system for my RV-7A, I'm certainly want a design where that does not happen.  This is one of the reasons people like us build our own airplanes - we get to engineer-out those little annoyances that we just have to put up with in certified  airplanes.

   Under what operating scenarios is it useful/necessary

   minimize the time between the glass being awake

   and reaching the end of the runway just prior

   to engine run-up?

   I recall some stories about the Blue-Mountain

   systems (hard drives?) taking perhaps 90

   seconds to wake up . . . but when was the

   last time you were ready to check mags less

   than, say 3-4 minutes after engine startup?

   I've reviewed as many of the airports I've

   visited that I can remember. I cannot recall

   any departure where engine run-up was accomplished

   for before the oil was warmed up a bit and I

   had taxied from parking to the run-up stand,

   certainly 4 minutes, sometimes 10. I think

   it took 15 minutes to get out of KCI once.

All true but, there are also thousands of quiet little airports where you can depart as quickly as you want to

   . . . the check list belongs to YOU . . . you

   can adjust sequences of events to fit hardware.

   Let us consider "draining the main battery"

   for the purposes of gathering the ATIS data

   and getting a clearance delivery. Suppose the

   e-bus runs 5A and the exercise takes 3 minutes.

   12v x 5a x 60s x 3m = 10,800 watt-seconds.

   Cranking the engine 12v x 200a x 10s = 24,000

   watt-seconds. What does the battery hold?

   12v x 5a x 60s x 120m = 432,000 watt-seconds.

   Okay, you used up 34,800 watt-seconds before

   the engine was lit for 35K/432K or 8 percent

   of the battery's capacity. If you're targeting

   80% of new capacity for banishing your battery

   to kiddie-car  duty, then the last flight

   will tax the battery to 10% of available

   capacity.

   The above analysis is a first order estimate

   and does not take into account vagaries of

   temperature and internal impedances of the

   battery but it's in the right church if not

   in the right pew.

   Whats is the return on investment for 5 more

   pounds of battery and two batteries to maintain

   instead of one?

   The value of this . . . or even more detailed

   analysis presumes that you KNOW what the

   drains are and what the battery's capabilities

   are after accounting for aforementioned

   vagaries AND targe> http://foru             - List Contribution Web Site -

nuckolls.bob(at)aeroelect
Guest

Posted: Sun Feb 02, 2014 3:39 pm Post subject: Essential Bus question

OK, let me write it here:



Watching the Garmin 430 in my Cherokee re-boot after engine start is 

very inconvenient.



   Stop-watch that for me some time. I'd really

   like to have a number on this widely discussed

   but never quantified driver of design goals.



Is it catastrophic? No.  Are there work-arounds? Certainly.  It's 

just a pain in the (at)ss.

In an experimental w/all glass, it would be even more annoying.



Now that I'm designing the electrical system for my RV-7A, I'm 

certainly want a design

where that does not happen.  This is one of the reasons people like 

us build our own

airplanes - we get to engineer-out those little annoyances that we just have to

put up with in certified airplanes.



   Then by all means do so. It's your airplane and your

   design goals. The question wasn't whether or not you

   wanted to do a particular thing, it was an invitation

   explore why you wanted to do it . . . hopefully for reasons

   firmly of your own choosing and not 'just because'

   hangar lore and legacy traditions dictated it.



   Brownout batteries have been discussed her on the list often

   for several years an even illustrated one approach

   in Z-10/8



http://tinyurl.com/7ro5yuc

All true but, there are also thousands of quiet little airports where you can

depart as quickly as you want to



   Yup . . . there are.  If a significant percentage

   of your departures are so expeditious that

   boot time on the glass becomes an impediment,

   then you have an element of fact that drives

   a different design goal.



   I'm trying head off any notions that just because

   one is considering a glass cockpit that a brownout

   battery is recommended . . . it comes with a price in

   weight and costs of ownership that may add little

   or no value.



   Bob . . .

tim2542(at)sbcglobal.net
Guest

Posted: Sun Feb 02, 2014 4:14 pm Post subject: Essential Bus question

Not to argue your points Bob, and I agree simple is often better, but I would just add that I don't want to wait 20 seconds for the screens to reboot after engine start as my engine data is there also and I want see oil pressure etc right away. 

And I much prefer to enter a lengthy flight plan with the prop off as my attention will be focused inside the plane, I'll admit on occasion I've looked up from the panel and discovered the plane moving. My flight plan will then be lost when I then crank the engine, unless I save it to memory, which I won't unless I'm using it again.  

And sometimes I take off with a hot engine, I'd rather not sit with the already hot engine running in the summer heat while I enter several waypoints in the Garmin. 

To me it's worth the 5lbs for the convenience, and the cost is easily overcome in fuel not burned. 

The beauty of EAB, built what you want, then live with your decisions.

Tim

 	  Quote: 	
		   On Feb 2, 2014, at 10:47 AM, "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> wrote:

 At 11:31 AM 2/2/2014, you wrote:

> 

> 

> I would just add a simple Brown out 7ah Alarm battery/Aux bus charged thru a Schottky diode and maybe a resistor is very simple & cheap to do. A lot of equipment now comes with multiple diode isolated power inputs making it easy.

> This allows flight plan entry and clearance requests before start up without draining the main battery,  keeps the GPS/NAV/COM and EFIS from rebooting when cranking the engine, and provides maybe 20-30 minutes of extra time to get back on the ground.

> Weight/cost is about $35 and 5 lbs. cheaper than a factory backup, which only powers one item.

> 

> Tim

  Good data points. Let us consider the premises

  underlying the evolution of Figure Z-07

 http://tinyurl.com/my9u3ud

  this shows a two battery/single alternator system

  for an electrically dependent engine. This

  exercise in 'electron gazing' grew out of Fred's

  project already fitted with a EXP-Bus. I could

  see a way to accommodate Fred's initial design

  goals for two batteries with a simple mod to

  the EXP-Bus . . . but I could see an alternative

  to Z-19 evolving from the deliberations . . .

  hence Z-07.

  Off in the distance, I think I see a single-battery

  variant of this architecture but that's possible

  only after we get real energy requirements data

  . . . and further refine the operating philosophy

  for the system. Tim's words raise useful questions

  that go directly to deliberations for sizing risks

  in a single-battery design.

  Where is it written or demonstrated that having

  the ship's processors 'reboot' is a bad thing?

  Under what operating scenarios is it useful/necessary

  minimize the time between the glass being awake

  and reaching the end of the runway just prior

  to engine run-up?

  I recall some stories about the Blue-Mountain

  systems (hard drives?) taking perhaps 90

  seconds to wake up . . . but when was the

  last time you were ready to check mags less

  than, say 3-4 minutes after engine startup?

  I've reviewed as many of the airports I've

  visited that I can remember. I cannot recall

  any departure where engine run-up was accomplished

  for before the oil was warmed up a bit and I

  had taxied from parking to the run-up stand,

  certainly 4 minutes, sometimes 10. I think

  it took 15 minutes to get out of KCI once.

  . . . the check list belongs to YOU . . . you

  can adjust sequences of events to fit hardware.

  Let us consider "draining the main battery"

  for the purposes of gathering the ATIS data

  and getting a clearance delivery. Suppose the

  e-bus runs 5A and the exercise takes 3 minutes.

  12v x 5a x 60s x 3m = 10,800 watt-seconds.

  Cranking the engine 12v x 200a x 10s = 24,000

  watt-seconds. What does the battery hold?

  12v x 5a x 60s x 120m = 432,000 watt-seconds.

  Okay, you used up 34,800 watt-seconds before

  the engine was lit for 35K/432K or 8 percent

  of the battery's capacity. If you're targeting

  80% of new capacity for banishing your battery

  to kiddie-car duty, then the last flight

  will tax the battery to 10% of available

  capacity.

  The above analysis is a first order estimate

  and does not take into account vagaries of

  temperature and internal impedances of the

  battery but it's in the right church if not

  in the right pew.

  Whats is the return on investment for 5 more

  pounds of battery and two batteries to maintain

  instead of one?

  The value of this . . . or even more detailed

  analysis presumes that you KNOW what the

  drains are and what the battery's capabilities

  are after accounting for aforementioned

  vagaries AND targeted end of life decisions.

 Bob . . .

Kellym

Joined: 10 Jan 2006
Posts: 1705
Location: Sun Lakes AZ

Posted: Sun Feb 02, 2014 4:14 pm Post subject: Essential Bus question

Virtually all glass have their own light weight backup batteries so do 

not have startup brown out issues unless no backup battery is installed.

I see very little value in being able to turn on GPS prior to start.

While one needs engine instrumentation prior to and during start, one 

does not need avionics on.

Of course newer avionics that allow faster input of flight plans than 

the 430 help, if that is the reason for turning on 430 before start.



On 2/2/2014 4:39 PM, Robert L. Nuckolls, III wrote:

 	  Quote: 	
		  



   Brownout batteries have been discussed her on the list often

   for several years an even illustrated one approach

   in Z-10/8



 http://tinyurl.com/7ro5yuc

 All true but, there are also thousands of quiet little airports where 

 you can

 depart as quickly as you want to



   Yup . . . there are.  If a significant percentage

   of your departures are so expeditious that

   boot time on the glass becomes an impediment,

   then you have an element of fact that drives

   a different design goal.



   I'm trying head off any notions that just because

   one is considering a glass cockpit that a brownout

   battery is recommended . . . it comes with a price in

   weight and costs of ownership that may add little

   or no value.



   Bob . . .

_________________
Kelly McMullen
A&P/IA, EAA Tech Counselor # 5286
KCHD

nuckolls.bob(at)aeroelect
Guest

Posted: Sun Feb 02, 2014 5:11 pm Post subject: Essential Bus question

At 06:14 PM 2/2/2014, you wrote:

 	  Quote: 	
		  



Not to argue your points Bob, and I agree simple is often better, 

but I would just add that I don't want to wait 20 seconds for the 

screens to reboot after engine start as my engine data is there also 

and I want see oil pressure etc right away.


	


    Yeah . . . that's an old saw that has been around

    since the Curtis Jenny . . . when sheared oil pump

    shafts were relatively common . . . along with a

    host of other ills associated with vintage engines.



    I've never encountered a pilot who's oil pump died

    at startup. I've flown lots of airplanes in cold

    weather that didn't show any pressure for 30-45

    seconds after start.



 	  Quote: 	
		  And I much prefer to enter a lengthy flight plan with the prop off 

as my attention will be focused inside the plane, I'll admit on 

occasion I've looked up from the panel and discovered the plane 

moving. My flight plan will then be lost when I then crank the 

engine, unless I save it to memory, which I won't unless I'm using it again.


	


 	  Quote: 	
		  And sometimes I take off with a hot engine, I'd rather not sit with 

the already hot engine running in the summer heat while I enter 

several waypoints in the Garmin.


	


    You mean its stored waypoints go away during

    reboot?



 	  Quote: 	
		  

To me it's worth the 5lbs for the convenience, and the cost is 

easily overcome in fuel not burned.

The beauty of EAB, built what you want, then live with your decisions.


	


   Absolutely. But why 5#? What did Eric decide about

   his brown-out eliminator? Perhaps we still need

   to refine the electronic bus-booster idea . . . it

   weights a few ounces and has no periodic maintenance

   requirements. Of course, a battery used only for

   brownout protection can be run until it dies . . .

   as long as the pilot doesn't included it in his/her

   calculations for battery only endurance.

   Bob . . .

rickofudall

Joined: 19 Sep 2009
Posts: 1392
Location: Udall, KS, USA

Posted: Mon Feb 03, 2014 5:28 am Post subject: Essential Bus question

Bob, There is more than inconvenience to not having engine instruments if you fly with a Rotax. Unlike the LyConosaurs, these engines are so tight, the wear limit on a piston is only .0015" and a standard new fit is .0000" to .0009", that to lose oil pressure is catastrophic within seconds. The example that I saw in school was an engine that the owner had hooked the oil hoses up backward. On first start up the engine ran for less than 10 seconds before it threw a rod and blew a big hole in the engine case. 



Rick Girard



On Sun, Feb 2, 2014 at 7:10 PM, Robert L. Nuckolls, III <nuckolls.bob(at)aeroelectric.com (nuckolls.bob(at)aeroelectric.com)> wrote:

  	  Quote: 	
		  --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com (nuckolls.bob(at)aeroelectric.com)>

  



 At 06:14 PM 2/2/2014, you wrote:

 

 	  Quote: 	
		   --> AeroElectric-List message posted by: Tim Andres <tim2542(at)sbcglobal.net (tim2542(at)sbcglobal.net)>

 



 Not to argue your points Bob, and I agree simple is often better, but I would just add that I don't want to wait 20 seconds for the screens to reboot after engine start as my engine data is there also and I want see oil pressure etc right away.

  

	
 

    Yeah . . . that's an old saw that has been around

    since the Curtis Jenny . . . when sheared oil pump

    shafts were relatively common . . . along with a

    host of other ills associated with vintage engines.

 

    I've never encountered a pilot who's oil pump died

    at startup. I've flown lots of airplanes in cold

    weather that didn't show any pressure for 30-45

    seconds after start.

 

  	  Quote: 	
		   And I much prefer to enter a lengthy flight plan with the prop off as my attention will be focused inside the plane, I'll admit on occasion I've looked up from the panel and discovered the plane moving. My flight plan will then be lost when I then crank the engine, unless I save it to memory, which I won't unless I'm using it again.

   And sometimes I take off with a hot engine, I'd rather not sit with the already hot engine running in the summer heat while I enter several waypoints in the Garmin.

 	
 



    You mean its stored waypoints go away during

    reboot?

 

  	  Quote: 	
		   

 To me it's worth the 5lbs for the convenience, and the cost is easily overcome in fuel not burned.

 The beauty of EAB, built what you want, then live with your decisions.

 	
 



   Absolutely. But why 5#? What did Eric decide about

   his brown-out eliminator? Perhaps we still need

   to refine the electronic bus-booster idea . . . it

   weights a few ounces and has no periodic maintenance

   requirements. Of course, a battery used only for

   brownout protection can be run until it dies . . .

   as long as the pilot doesn't included it in his/her

   calculations for battery only endurance.

 

 

   Bob . . . 

 

 ====================================

 -List" target="_blank">http://www.matronics.com/Navigator?AeroElectric-List

 ====================================

 http://forums.matronics.com

 ====================================

 le, List Admin.

 ="_blank">http://www.matronics.com/contribution

 ====================================

 

 

 

 



	




-- 

Zulu Delta

Mk IIIC

Thanks, Homer GBYM

It isn't necessary to have relatives in Kansas City in order to be unhappy.

   - Groucho Marx

 

  [quote][b]

_________________
The smallest miracle right in front of you is enough to make you happy....

nuckolls.bob(at)aeroelect
Guest

Posted: Mon Feb 03, 2014 10:51 am Post subject: Essential Bus question

At 07:27 AM 2/3/2014, you wrote:

 	  Quote: 	
		  Bob, There is more than inconvenience to not having engine 

instruments if you fly with a Rotax. Unlike the LyConosaurs, these 

engines are so tight, the wear limit on a piston is only .0015" and 

a standard new fit is .0000" to .0009", that to lose oil pressure is 

catastrophic within seconds. The example that I saw in school was an 

engine that the owner had hooked the oil hoses up backward. On first 

start up the engine ran for less than 10 seconds before it threw a 

rod and blew a big hole in the engine case.


	




   Back in the day, the oil pressure gage was the same

   device on grandpa's Ferguson tractor . . . a pressure

   gage plumbed to the engine with a small diameter

   tube.



   In cold weather, the 50W oil would turn to road

   tar in the tubing and delay accurate readings of

   the gage by many seconds.



   If I had an engine so critically vulnerable to

   low oil pressure, then I'd add a pressure switch

   as close as practical to the engine plumbed in

   with any transducer intended to drive electronics.



   10 seconds to destruct because the oil pressure

   was absent on THAT start? Broke a rod because the

   piston fits got tight? I'm skeptical. Pistons

   seizing up progressively in the bores will

   load up the engine until it stalls.



   I worked a Rotax 912 accident that the owner tried to

   blame on an electrical issue with ignition. I proved

   the ignition system to be intact . . . but in the

   accident narrative, the owner had taxied around for

   30+ minutes 'getting the feel of the airplane' before

   he decided to take off. On climb out the engine

   slowly lost power . . . as if somebody was closing

   the throttle. He descended into the trees, destroyed

   the airplane and received a back injury. I told my

   client attorney that they should do a teardown

   of the engine and inspect cylinders for signs of

   seizing due to overheat. Whether engine seizes

   due to poor oil, air or water flow, the behavior is

   the same.



   I'll bet that engine had been in trouble for some

   time and only decided to give up the ghost on that start-

   event. It probably would have shelled out pretty

   soon whether it had oil pressure or not.

   Bob . . .

rickofudall

Joined: 19 Sep 2009
Posts: 1392
Location: Udall, KS, USA

Posted: Mon Feb 03, 2014 12:58 pm Post subject: Essential Bus question

Bob, As one Rotax mechanic I know put it quite succinctly, "The worst enemy of the Rotax 912 is their owners". As for the blown up engine I saw, the school I attended was taught by the owner of the Rotax North American distributorship. I cannot fathom why he would make up such a story. If the owner had followed the manual, prelubed the engine, and then burped the oil system (the 912 has a dry sump oiling system that has no scavenge pump but instead relies upon blow by to pressurize the crankcase and push the oil out) he'd never have had a problem.

 



Rick

do not archive



On Mon, Feb 3, 2014 at 12:50 PM, Robert L. Nuckolls, III <nuckolls.bob(at)aeroelectric.com (nuckolls.bob(at)aeroelectric.com)> wrote:

  	  Quote: 	
		  --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com (nuckolls.bob(at)aeroelectric.com)>

  



 At 07:27 AM 2/3/2014, you wrote:

  	  Quote: 	
		   Bob, There is more than inconvenience to not having engine instruments if you fly with a Rotax. Unlike the LyConosaurs, these engines are so tight, the wear limit on a piston is only .0015" and a standard new fit is .0000" to .0009", that to lose oil pressure is catastrophic within seconds. The example that I saw in school was an engine that the owner had hooked the oil hoses up backward. On first start up the engine ran for less than 10 seconds before it threw a rod and blew a big hole in the engine case.

  	
 

 



   Back in the day, the oil pressure gage was the same

   device on grandpa's Ferguson tractor . . . a pressure

   gage plumbed to the engine with a small diameter

   tube.

 

   In cold weather, the 50W oil would turn to road

   tar in the tubing and delay accurate readings of

   the gage by many seconds.

 

   If I had an engine so critically vulnerable to

   low oil pressure, then I'd add a pressure switch

   as close as practical to the engine plumbed in

   with any transducer intended to drive electronics.

 

   10 seconds to destruct because the oil pressure

   was absent on THAT start? Broke a rod because the

   piston fits got tight? I'm skeptical. Pistons

   seizing up progressively in the bores will

   load up the engine until it stalls.

 

   I worked a Rotax 912 accident that the owner tried to

   blame on an electrical issue with ignition. I proved

   the ignition system to be intact . . . but in the

   accident narrative, the owner had taxied around for

   30+ minutes 'getting the feel of the airplane' before

   he decided to take off. On climb out the engine

   slowly lost power . . . as if somebody was closing

   the throttle. He descended into the trees, destroyed

   the airplane and received a back injury. I told my

   client attorney that they should do a teardown

   of the engine and inspect cylinders for signs of

   seizing due to overheat. Whether engine seizes

   due to poor oil, air or water flow, the behavior is

   the same.

 

   I'll bet that engine had been in trouble for some

   time and only decided to give up the ghost on that start-

   event. It probably would have shelled out pretty

   soon whether it had oil pressure or not.

 

 

   Bob . . .  

 

 ====================================

 -List" target="_blank">http://www.matronics.com/Navigator?AeroElectric-List

 ====================================

 http://forums.matronics.com

 ====================================

 le, List Admin.

 ="_blank">http://www.matronics.com/contribution

 ====================================

 

 

 

 



	




-- 

Zulu Delta

Mk IIIC

Thanks, Homer GBYM

It isn't necessary to have relatives in Kansas City in order to be unhappy.

   - Groucho Marx

 

  [quote][b]

_________________
The smallest miracle right in front of you is enough to make you happy....

nuckolls.bob(at)aeroelect
Guest

Posted: Mon Feb 03, 2014 5:26 pm Post subject: Essential Bus question

At 02:57 PM 2/3/2014, you wrote:

 	  Quote: 	
		  Bob, As one Rotax mechanic I know put it quite succinctly, "The 

worst enemy of the Rotax 912 is their owners".

As for the blown up engine I saw, the school I attended was taught 

by the owner of the Rotax North American distributorship. I cannot 

fathom why he would make up such a story. If the owner had followed 

the manual, prelubed the engine, and then burped the oil system (the 

912 has a dry sump oiling system that has no scavenge pump but 

instead relies upon blow by to pressurize the crankcase and push the 

oil out) he'd never have had a problem.


	


  But a broken rod in 10 seconds? Rod failures

  tend to be the byproduct of hammering of the

  end cap after the bearing is worn . . . a process

  that takes hours. To break the rod with the

  torque offered by a seized bearing that

  lacked lubrication for 10 seconds doesn't

  fit with the physics. You cited tight fits

  for the pistons and segued to a broken

  rod.



  To be sure, we don't have the benefit of

  failure analysis on the subject engine

  but using what appears to be capitalization

  of outlier event to re-enforce a perfectly

  reasonable caution to be certain of engine

  lubrication smells of "teaching by

  sensationalism." This sort of teaching is core

  to many the useless if not expensive

  ol' mechanic's tales that plague our

  community.



  I'm not calling him a liar . . . but I am

  skeptical based on the cause/effect cited.

   Bob . . .

rickofudall

Joined: 19 Sep 2009
Posts: 1392
Location: Udall, KS, USA

Posted: Mon Feb 03, 2014 6:24 pm Post subject: Essential Bus question

Bob, You also have to take into account that unlike the LyCo's, the Rotax has a five piece crank that is pressed together with nothing but the pressure of the fit to keep it together and aligned. I would imagine the trail of tears would include a piston seizure that causes the crank to come out of alignment which not only destroys a bearing or two, but gives the various crank sections a chance to beat upon each other. The reason for the multipiece crank is so that it can be made shorter by reducing the clearance between the side of the rod, see picture. With so little clearance between the rod and the adjacent crank web the twisted, misaligned crank now has a chance to really start beating on the rods, the piston skirts, and any pieces that have come loose. Of course the Rotax engineers have reduced clearances between the rotating assembly and the case halves to shave off more weight and by now the bearings are not only being twisted out of their seats but the case webs are being hammered, too. Well, that's about all I can conjecture about the cause and effect trail, but you get the idea. Rotax engines are just a different animal.

Rick

do not archive



 



On Mon, Feb 3, 2014 at 7:25 PM, Robert L. Nuckolls, III <nuckolls.bob(at)aeroelectric.com (nuckolls.bob(at)aeroelectric.com)> wrote:

  	  Quote: 	
		  --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com (nuckolls.bob(at)aeroelectric.com)>

  



 At 02:57 PM 2/3/2014, you wrote:

  	  Quote: 	
		   Bob, As one Rotax mechanic I know put it quite succinctly, "The worst enemy of the Rotax 912 is their owners".

 As for the blown up engine I saw, the school I attended was taught by the owner of the Rotax North American distributorship. I cannot fathom why he would make up such a story. If the owner had followed the manual, prelubed the engine, and then burped the oil system (the 912 has a dry sump oiling system that has no scavenge pump but instead relies upon blow by to pressurize the crankcase and push the oil out) he'd never have had a problem.

  	
 



  But a broken rod in 10 seconds? Rod failures

  tend to be the byproduct of hammering of the

  end cap after the bearing is worn . . . a process

  that takes hours. To break the rod with the

  torque offered by a seized bearing that

  lacked lubrication for 10 seconds doesn't

  fit with the physics. You cited tight fits

  for the pistons and segued to a broken

  rod.

 

  To be sure, we don't have the benefit of

  failure analysis on the subject engine

  but using what appears to be capitalization

  of outlier event to re-enforce a perfectly

  reasonable caution to be certain of engine

  lubrication smells of "teaching by

  sensationalism." This sort of teaching is core

  to many the useless if not expensive

  ol' mechanic's tales that plague our

  community.

 

  I'm not calling him a liar . . . but I am

  skeptical based on the cause/effect cited.

 

 

   Bob . . . 

 

 ====================================

 -List" target="_blank">http://www.matronics.com/Navigator?AeroElectric-List

 ====================================

 http://forums.matronics.com

 ====================================

 le, List Admin.

 ="_blank">http://www.matronics.com/contribution

 ====================================

 

 

 

 



	




-- 

Zulu Delta

Mk IIIC

Thanks, Homer GBYM

It isn't necessary to have relatives in Kansas City in order to be unhappy.

   - Groucho Marx

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The smallest miracle right in front of you is enough to make you happy....

tim2542(at)sbcglobal.net
Guest

Posted: Mon Feb 03, 2014 7:08 pm Post subject: Essential Bus question

I think the multi piece crank is needed when they use one piece rods with roller bearings. Still hard to imagine a 10 sec failure. An oil change now becomes a major event in the life of your engine!

Tim

[quote] On Feb 3, 2014, at 6:23 PM, Richard Girard <aslsa.rng(at)gmail.com> wrote:

 Bob, You also have to take into account that unlike the LyCo's, the Rotax has a five piece crank that is pressed together with nothing but the pressure of the fit to keep it together and aligned. I would imagine the trail of tears would include a piston seizure that causes the crank to come out of alignment which not only destroys a bearing or two, but gives the various crank sections a chance to beat upon each other. The reason for the multipiece crank is so that it can be made shorter by reducing the clearance between the side of the rod, see picture. With so little clearance between the rod and the adjacent crank web the twisted, misaligned crank now has a chance to really start beating on the rods, the piston skirts, and any pieces that have come loose. Of course the Rotax engineers have reduced clearances between the rotating assembly and the case halves to shave off more weight and by now the bearings are not only being twisted out of their seats but the case webs are being hammered, too.

 Well, that's about all I can conjecture about the cause and effect trail, but you get the idea. Rotax engines are just a different animal.

 Rick

 do not archive

> On Mon, Feb 3, 2014 at 7:25 PM, Robert L. Nuckolls, III <nuckolls.bob(at)aeroelectric.com> wrote:

> 

> 

> At 02:57 PM 2/3/2014, you wrote:

>> Bob, As one Rotax mechanic I know put it quite succinctly, "The worst enemy of the Rotax 912 is their owners".

>> As for the blown up engine I saw, the school I attended was taught by the owner of the Rotax North American distributorship. I cannot fathom why he would make up such a story. If the owner had followed the manual, prelubed the engine, and then burped the oil system (the 912 has a dry sump oiling system that has no scavenge pump but instead relies upon blow by to pressurize the crankcase and push the oil out) he'd never have had a problem.

> 

>  But a broken rod in 10 seconds? Rod failures

>  tend to be the byproduct of hammering of the

>  end cap after the bearing is worn . . . a process

>  that takes hours. To break the rod with the

>  torque offered by a seized bearing that

>  lacked lubrication for 10 seconds doesn't

>  fit with the physics. You cited tight fits

>  for the pistons and segued to a broken

>  rod.

> 

>  To be sure, we don't have the benefit of

>  failure analysis on the subject engine

>  but using what appears to be capitalization

>  of outlier event to re-enforce a perfectly

>  reasonable caution to be certain of engine

>  lubrication smells of "teaching by

>  sensationalism." This sort of teaching is core

>  to many the useless if not expensive

>  ol' mechanic's tales that plague our

>  community.

> 

>  I'm not calling him a liar . . . but I am

>  skeptical based on the cause/effect cited.

> 

> 

> 

>   Bob . . . 

> 

> =========================>> -List" target="_blank">http://www.matronics.com/Navigator?AeroElectric-List

> =========================>> http://forums.matronics.com

> =========================>> le, List Admin.

> ="_blank">http://www.matronics.com/contribution

> =========================> 

 -- 

 Zulu Delta

 Mk IIIC

 Thanks, Homer GBYM

 It isn't necessary to have relatives in Kansas City in order to be unhappy

mrspudandcompany(at)veriz
Guest

Posted: Tue Feb 04, 2014 5:33 am Post subject: Essential Bus question

You also have to take into account that unlike the LyCo's, the Rotax  has a five piece crank that is pressed together with nothing but the pressure of  the fit to keep it together and aligned. I would imagine the trail of tears  would include a piston seizure that causes the crank to come out of alignment  which not only destroys a bearing or two, but gives the various crank sections a  chance to beat upon each other. The reason for the multipiece crank is so that  it can be made shorter by reducing the clearance between the side of the rod,  see picture. With so little clearance between the rod and the adjacent crank web  the twisted, misaligned crank now has a chance to really start beating on the  rods, the piston skirts, and any pieces that have come loose. Of course the  Rotax engineers have reduced clearances between the rotating assembly and the  case halves to shave off more weight and by now the bearings are not only being  twisted out of their seats but the case webs are being hammered, too.

  	  Quote: 	
		      	  Quote: 	
		        	  Quote: 	
		                I find this scenerio to be highly        unlikely!  If this were the case, then I would wager that there would        be cases of this type of failure during normal operation, due to the        stress and vibration created during high power running.

        

       Roger



	
	
	
  

I am using the Free version of SPAMfighter.SPAMfighter has removed 1850 of my spam emails to date.Do you have a slow PC? Try a free scan!     [quote][b]

Eric M. Jones

Joined: 10 Jan 2006
Posts: 565
Location: Massachusetts

Posted: Wed Feb 05, 2014 12:48 pm Post subject: Re: Rotax Crank was Essential Bus question

 	  Quote: 	
		   You also have to take into account that unlike the LyCo's, the Rotax has a five piece crank that is pressed together with nothing but the pressure of the fit to keep it together and aligned. I would imagine the trail of tears would include a piston seizure that causes the crank to come out of alignment which not only destroys a bearing or two, but gives the various crank sections a chance to beat upon each other. The reason for the multipiece crank is so that it can be made shorter by reducing the clearance between the side of the rod, see picture. With so little clearance between the rod and the adjacent crank web the twisted, misaligned crank now has a chance to really start beating on the rods, the piston skirts, and any pieces that have come loose. Of course the Rotax engineers have reduced clearances between the rotating assembly and the case halves to shave off more weight and by now the bearings are not only being twisted out of their seats but the case webs are being hammered, too.

      I find this scenerio to be highly unlikely!  If this were the case, then I would wager that there would be cases of this type of failure during 

normal operation, due to the stress and vibration created during high power running.   Roger 	




Let me venture way outside my pay-grade and offer an opinion that the Rotax multipiece crank is in no way an inferior design, and in fact offers lots of advantages:

 

1) Cost

2) The connecting rods need no end bearing caps, thus they are stronger and lighter. 

3) Exceptional resistance to failure from torsional vibration.

4) The ability to use different metals for the various parts.

5) Shorter crank.

6) The ability to use roller bearings. (I have no idea if they actually should or do).



As long as the rod and main bearings are good, the idea that the crank can come apart is simply a distraction. Porsche 4-cam racing engines used a similar design, although they keyed theirs. But Still... Your Mileage May Vary.



Off Topic...  Do not Archive

_________________
Eric M. Jones
www.PerihelionDesign.com
113 Brentwood Drive
Southbridge, MA 01550
(508) 764-2072
emjones(at)charter.net

Mauledriver(at)nc.rr.com
Guest

Posted: Fri Feb 07, 2014 2:31 pm Post subject: Essential Bus question

Sorry about adding to this rather old discussion but I've been away for 

awhile.



I finished my RV10 in 2011 which means that I designed my electrical 

system and panel around 2008 for a 2009-2010 build.



I have 3 GRT HX EFISs - 2 aimed at the pilot, 1 at the passenger. They 

supply synthetic vision, moving map, weather, traffic and a complete 

suite of engine stats.   No light weight backup batteries can be 

configured  at the factory with these systems.   These screens have no 

integral on/off switch. I chose not to add any switches or operable 

CBs.  They come on with the master and will usually reboot when my IO540 

cold starts with a single, fresh PC 680 battery.



The GPS WAAS smarts for this system are supplied by a G430W.



I am a serious traveler with this machine and practically all flight are 

on IFR plans.  My normal routine for all flights is to file my plan 

using Foreflight on an iPad.  Whenever at an airport with clearance 

delivery, or when departing into IMC conditions, I obtain my clearance 

on the ground, before engine start, and enter it into my iPad and then 

into my G430.  Many times in congested areas, this entry is followed by 

no small amount of study.  As my aging mind continues to fog over, I'm 

finding that the study time grows.



Here's the challenge on G430 based panels; it loses any entered flight 

plan when powered off.  An engine start that reboots my GRTs, reboots my 

G430.



An acute challenge on 430 based panels when used for flights around the 

Wash DC area or for flights along Florida's Atlantic coast is that the 

G430 does not know what a Victor airway is. These are flights I make 

regularly and clearances in these areas typically still include Victor 

airways.  So in the routine described above, entry into the iPad 

generates the necessary waypoints to any Victor airways.  Accurate entry 

of these waypoints into the G430 is important and there's no way I want 

to redo the work.



As Bob would put it, this is the 'kitchen sink' I choose to fly with.  I 

think it's fantastic and works very very well for me. It's now a well 

grooved swing.  The inability of some (e.g. Bob, not necessarily you 

Kelly but I did choose to respond to your post) to 'get' this 

requirement for this pilot, seems to me is just an inability to see past 

old school experience or perhaps your current pleasure flying routines.



I have a Z-14 with 2 batts, 2 alts, and 2 buses and I REALLY like it.  I 

bring up the 'kitchen sink' on one battery, get my clearances, enter 

them into my systems, study my departure plan when doing complicated 

airspace or low IMC departures and then bring up the 2nd battery bus, 

cross link them and start my engine.  Everything stays up.  Before 

takeoff I've learned, per Bob, to de-link the buses and off I go.



Per Bob, I've eliminated any semblance of an avionics bus, extra 

switches or CBs.  After a few operational adjustments and refinements 

(Thanks Bob!), the 'overkill' of a Z-14 has given me exactly what I 

think I need.



I need my avionics on before start and I have a big kitchen sink that 

takes care of the dishes just like I want them done.  So can we please 

stop dismissing this approach to equipping and traveling in our very 

fine OBAM aircraft  within the user fee free ATC system we have?  Some 

of us do it every day because that's the way we choose to roll.



PS: I've been out of the loop island hopping the Bahamas. Recommend it 

highly.  What an adjustment flying VFR from place to place!  However, I 

still used the same procedures because that's what standard procedures 

are for.



Bill "It's pretty darn good in the Bahamas" Watson

N215TG

On 2/2/2014 7:14 PM, Kelly McMullen wrote:

 	  Quote: 	
		   

 <kellym(at)aviating.com>



 Virtually all glass have their own light weight backup batteries so do 

 not have startup brown out issues unless no backup battery is installed.

 I see very little value in being able to turn on GPS prior to start.

 While one needs engine instrumentation prior to and during start, one 

 does not need avionics on.

 Of course newer avionics that allow faster input of flight plans than 

 the 430 help, if that is the reason for turning on 430 before start.

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