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Let's not loose focus

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nuckolls.bob(at)aeroelect
Guest

Posted: Tue Jun 30, 2020 8:38 am Post subject: Let's not loose focus

 	  Quote: 	
		  

 The only real shortcoming I have found is that it does not include a fuse component.  It shows the current during simulation so you can size things, but it would be great to be able to install a fuse and test all combinations of devices to ensure that calculations for wire size and such have been done correctly. 	


    Is this a simulation app? Calculations for wire size etc?

    A word of caution. Take care spending a lot of time

    wrestling with software installation and familiarization

    that (1) doesn't add to meeting design goals and

    (2) simply goes to confirmation of exceedingly rudimentary

    decisions . . . wire sizes and fuses . . . really?



    The PRIMARY concern is to craft a failure tolerant

    system that has low parts count, minimized crew

    controls that beg for proper decisions in flight

    followed up by minimized weight and cost of ownership.



    All those AC43-13 driven 'calculations' and admonitions

    are like studying how to boil eggs . . . 



    There's a thread running now that claims 

    roots in Z101. ALL of the z-figures

    were crafted with a particular airframe/mission

    in mind. Occasionally I run a across a builder's

    assertion that "I took Zxx and crafted a really

    whippy electrical system." Then I find the

    drawings only slightly resemble the the

    referenced Z-figure due poorly reasoned

    changes.



    In some cases, the differences created

    failure modes hazardous to people and other

    living things.



    The builder of this airplane attended my

    seminar and bought the book . . . but

    failed to join us here on the List before

    crafting his own "whippy" electrical system:



     https://tinyurl.com/msfmldj



    There was no critical review of the electrical

    system condition/architecture for this

    accident . . . but I'd bet $100 that

    root cause for this incident would have

    been one of those "Gosh . . . I could have

    had a V8" moments:



     https://tinyurl.com/y7xksy6v



    Finally, there's this sad story of a

    horrifyingly dismissive attitude toward

    the simple physics of flight, aviation

    legacy processes/practices and just

    common sense.



     https://tinyurl.com/mwbk9qs



    Root cause for ALL of these (an many

    more) bad days in the cockpit was

    stone simple.



    Years ago, I used this tag on my email

    signature:

    



                    //// 

                   (o o) 

    ===========o00o=(_)=o00o========= 

    < Go ahead, make my day . . .   > 

    < show me where I'm wrong.      > 

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

   

   This was in no way intended to be tongue-

   in-cheek . . . it's serious . . . some

   times deadly serious.



   If I've put my foot in a tar bucket,

   I'm the FIRST person that needs to know about

   it. A teacher's worst nightmare is the

   discovery of an ignorant or careless complicity

   in the dissemination of poor if not hazardous

   information.



   If one wishes to exploit a z-figure,

   then start with the drawing AS-PUBLISHED.

   Study it for failure to meet personal design

   goals. If changes are indicated . . . DISCUSS

   THOSE GOALS RIGHT HERE on the List. If changes

   are warranted or a new z-figure is useful

   then by all means let's do it. But make sure

   that design goals are (1) realistic

   and (2) improve the failure mode effects analysis.

   This List is more than a SOURCE FOR GOOD

   info . . . it's a FILTER FOR BAD info. 



   To my way of thinking no single failure will

   create an emergency situation. Further, your

   plan-B checklist should have a minimum of crew

   tasks for failure mitigation (like flip two

   switches . . . and keep flying?) and no

   requirement for in-flight analysis. Save those gray-

   mater exercises for in the hangar.



   Trust me . . . wire and fuse sizes are

   wwwaaayy down the list of your building

   concerns.



 

   Bob . . .

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supik

Joined: 22 Aug 2018
Posts: 70

Posted: Wed Jul 01, 2020 1:37 am Post subject: Re: Let's not loose focus

 	  Quote: 	
		  There's a thread running now that claims 

    roots in Z101. ALL of the z-figures

    were crafted with a particular airframe/mission

    in mind. Occasionally I run a across a builder's

    assertion that "I took Zxx and crafted a really

    whippy electrical system." Then I find the

    drawings only slightly resemble the the

    referenced Z-figure due poorly reasoned

    changes.



    In some cases, the differences created

    failure modes hazardous to people and other

    living things. 	




I guess it's me. That's the reason I shared my schematics on this forum. I don't need to be an example for accident analysis post-mortem. I would appreciate your comments. I am especially interested in NO GO issues and failure analysis. 



I understand a load analysis is required to determine proper fuse ratings+wire size -I'll attach the load analysis to my thread..



Where I think it will work, you might find a critical issue..

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_________________
Igor

RV10 in progress

nuckolls.bob(at)aeroelect
Guest

Posted: Wed Jul 01, 2020 7:21 am Post subject: Let's not loose focus

 	  Quote: 	
		  

 I guess it's me. That's the reason I shared my schematics on this forum. I don't need to be an example for accident analysis post-mortem. I would appreciate your comments. I am especially interested in NO GO issues and failure analysis. 



 I understand a load analysis is required to determine proper fuse ratings+wire size -I'll attach the load analysis to my thread..



 Where I think it will work, you might find a critical issue.. 	


    Please don't take anything I wrote personally . . .

    in fact, by bringing your ideas and questions to

    the List, you do'n the right thing!



    Keep in mind that there are a lot

    of subscribers to this list who don't

    actively participate. Nonetheless they

    find value in watching what passes by.



    I try to tailor my offerings for a CLASS

    as opposed to individuals. We haven't had

    a personality clash on the List since

    GMCJetpilot days . . . and I'm hoping

    that doesn't happen again.



    I've not engaged in your project as

    yet for a variety of reasons not the

    least of which is time. At the same

    time, I'm intently interested in how

    the rest of the 'team' are rising

    to your cause.



    I am encouraged by what I'm reading.

    At the same time, I'm protective of our

    mission and process here. Whenever I

    encounter a project wherein the builder

    claims some foundation based on the

    AeroElectric Connection, I have an

    obligation to my readers and all who

    participate here to make sure that the

    mission and process are not being diluted

    or modified without foundation in physics

    and critical thought.



    Keep up the good work guys!



    P.S. Remember that fuses/breaker protect

    wire. The constellation electro-whizzies

    in our airplanes could not care less what size

    wire supplies energy as long as it

    is adequate and reliable. Had a reader

    some years ago who made a good deal on a

    nearly  full spool of 20AWG Tefzel wire.

    He wondered if there was any prohibition

    for using this wire for everything.



    The answer was "no problem" . . . slightly

    heavier but it fits all the 20AWG d-sub pins

    and PIDG termials were no problem either.

    He COULD populate the fuse block entirely

    with 7A fuses or anything lower that wouldn't

    nuisance trip.



    That project would probably set any faithful

    adherent to AC43-13 into fits of apoplexy

    while in fact, except for a few ounces

    more empty weight on the airplane, no

    design goals for safety or operation were

    being ignored . . . and he saved a goodly

    bit of money on wire and time for having to

   'optimize' each fuse/feeder decision.



 

   Bob . . .

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Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:

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