---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Thu 01/23/25: 1 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 08:55 AM - Re: Re: Switch Schemes for Reliability (Finn Lassen) ________________________________ Message 1 _____________________________________ Time: 08:55:03 AM PST US Subject: Re: AeroElectric-List: Re: Switch Schemes for Reliability From: Finn Lassen 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: >> >> >> 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. > ------------------------------------------------------------------------------------- Other Matronics Email List Services ------------------------------------------------------------------------------------- Post A New Message aeroelectric-list@matronics.com UN/SUBSCRIBE http://www.matronics.com/subscription List FAQ http://www.matronics.com/FAQ/AeroElectric-List.htm Web Forum Interface To Lists http://forums.matronics.com Matronics List Wiki http://wiki.matronics.com Full Archive Search Engine http://www.matronics.com/search 7-Day List Browse http://www.matronics.com/browse/aeroelectric-list Browse Digests http://www.matronics.com/digest/aeroelectric-list Browse Other Lists http://www.matronics.com/browse Live Online Chat! http://www.matronics.com/chat Archive Downloading http://www.matronics.com/archives Photo Share http://www.matronics.com/photoshare Other Email Lists http://www.matronics.com/emaillists Contributions http://www.matronics.com/contribution ------------------------------------------------------------------------------------- These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.