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1. 08:55 AM - Re: Re: Switch Schemes for Reliability (Finn Lassen)
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| Subject: | Re: Switch Schemes for Reliability |
Going through posts here from 2020 forward.
Very disappointed in your reply here, Bob, considering you did an
autopsy on a PC680 that Joe Gores sent you in 2016 and found that the
battery failed open.
Finn
On 4/30/2024 8:06 PM, Robert L. Nuckolls, III wrote:
> At 06:16 PM 4/20/2024, you wrote:
>> <wsimpso1@comcast.net>
>>
>> Recently I spotted a document from a well known brand of EFII
>> recommending an Essential Buss backed up with a Aux Battery and
>> simple switch to connect it. While this is supposed to make powering
>> the engine possible even if the Main Battery Bus goes cold,
>
> *Under what circumstances would your main battery
> ever 'go cold'?
> *
> When maintained with century old practices
> for system reliability, a battery can
> be the most reliable source of energy in
> the system. So finding yourself lacking in
> battery supplied energy means you've lost
> all engine driven sources, your battery
> is inadequate to the task of meeting your
> battery only endurance goals; -OR- your system
> architecture/craftsmanship fails to eliminate
> all single points of failure in energy
> conduction pathways to accessories necessary
> for comfortable completion of a flight.
>
> Adding any sort of 'back up' battery to a
> system only adds to the number of devices
> that beg for $time$ to maintain airworthiness
> for yet another commodity . . . a thing
> that begins to degrade, be consumed the day you
> installed it. Tires, drive belts, engine oil, propeller
> blades, FUEL, etc are all things we fuss over
> every flight as a matter of course . . . walk-around
> during pre-flight is drilled into us from
> day-one. But my flight instructor never said
> a peep about batteries.
>
> For as long as I can recall reading the
> dark-n-stormy-night narratives in the aviation
> rags, pilots who survived the dark-panel-syndrome
> never once suggested that the battery in
> their airplane was not properly evaluated,
> maintained or utilized for comfortable
> completion of flight under the circumstances
> they experienced.
>
> It's easy to debate 'reliability' at length
> and with great enthusiasm. It's tempting
> to pile on 'back-ups' at the risk of increasing
> weight, cost of ownership and complexity of operation
> . . . complexity that only work against 'aviate, navigate,
> communicate' when things are not going well in the
> cockpit.
>
> I'll suggest a FOURTH feature in the famous
> axiom for emergency management: 'First aviate,
> then navigate, then communicate, but last and
> certainly least, FIDDLE WITH STUFF ON THE PANEL'.
>
> Having a battery 'go cold' is the final chapter
> in a litany of failures that PRECEDE loss of the
> the battery. Things over which we have absolute
> control.
>
> I've not forgotten about you guys. The new
> crowbar OVM project is sitting on the bench
> waiting for a window of opportunity amongst other
> matters. Additionally, we need to spool up
> the discussion on Figure Z-101. I'm increasingly
> of the opinion that Z-101 should be the ONLY
> z-figure in any 'upgrade' to the connection.
>
> It has the opportunity of being the legos/
> tinkertoy/modular plug-n-play system with options
> that adress EVERY electrical system configuration
> requirement from ultra-light to LA-IVP with all
> the 'goodies'.
>
> But we need a cogent, convincing narrative to
> accompany Z-101 . . . a option/by/option
> account of when, why and how any particular
> feature should be considered.
>
> >Recently I spotted a document from a well known brand of EFII
> >recommending an Essential Bus backed up with a Aux Battery
> >and simple switch to connect it.
>
> Yeah, Klaus was of similar opinion when I met
> him back in '86 . . . and in all years since. So
> to have MOST producers of really slick electro-whizzies
> in years since. It's really easy to suggest that
> "adding back up to keep MY miracle product
> powered and happy" is a good thing to do . . .
> but I'll wager that few if any have brought
> the forces of experience and thoughtful Failure
> Mode Effects Analysis to bear on their recommendations.
>
> The goal: craft and maintain a system with an
> extremely high probability of bringing
> you home without breaking a sweat. Every
> failure is a maintenance even, not an
> emergency.
>
> Bob . . .
>
> ////
> (o o)
> ===========o00o=(_)=o00o========
> < Go ahead, make my day . . . >
> < show me where I'm wrong. >
> ================================
>
> In the interest of creative evolution
> for the-best-we-know-how-to-do based
> on physics and repeatable experiment.
>
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