X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Sun, 07 Aug 2011 10:56:47 -0400 Message-ID: X-Original-Return-Path: Received: from imr-ma03.mx.aol.com ([64.12.206.41] verified) by logan.com (CommuniGate Pro SMTP 5.4.1) with ESMTP id 5083586 for lml@lancaironline.net; Fri, 05 Aug 2011 21:49:12 -0400 Received-SPF: pass receiver=logan.com; client-ip=64.12.206.41; envelope-from=Sky2high@aol.com Received: from mtaomg-mb02.r1000.mx.aol.com (mtaomg-mb02.r1000.mx.aol.com [172.29.41.73]) by imr-ma03.mx.aol.com (8.14.1/8.14.1) with ESMTP id p761mV3k026323 for ; Fri, 5 Aug 2011 21:48:31 -0400 Received: from core-mta003b.r1000.mail.aol.com (core-mta003.r1000.mail.aol.com [172.29.234.137]) by mtaomg-mb02.r1000.mx.aol.com (OMAG/Core Interface) with ESMTP id 4F0D9E000086 for ; Fri, 5 Aug 2011 21:48:31 -0400 (EDT) From: Sky2high@aol.com X-Original-Message-ID: <16cf3.73c7690f.3b6df76f@aol.com> X-Original-Date: Fri, 5 Aug 2011 21:48:31 -0400 (EDT) Subject: Re: [LML] Re: Fw: Re: Re-doing my panel - carefully thinking through failures X-Original-To: lml@lancaironline.net MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="part1_16cf3.73c7690f.3b6df76f_boundary" X-Mailer: AOL 9.6 sub 5004 X-AOL-IP: 24.1.9.48 X-Originating-IP: [24.1.9.48] x-aol-global-disposition: G X-AOL-SCOLL-SCORE: 0:2:488013728:93952408 X-AOL-SCOLL-URL_COUNT: 0 x-aol-sid: 3039ac1d29494e3c9d6f66b6 --part1_16cf3.73c7690f.3b6df76f_boundary Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Content-Language: en Try this =20 _http://www.periheliondesign.com/powerschottkydiodes.htm_=20 (http://www.periheliondesign.com/powerschottkydiodes.htm)=20 =20 What, me worry? ;<} =20 =20 In a message dated 8/5/2011 7:44:36 P.M. Central Daylight Time, =20 colyncase@earthlink.net writes: At the risk of topic drift.....I put in those big fat diodes to my=20 essential bus also. =20 Since them I'm wondering if there's a failure mode on one bus that crosses= =20 the diodes and takes out the other bus. Colyn On Aug 5, 2011, at 10:37 AM, Bill Harrelson wrote: =20 =20 Hi Fred, =20 I like your simplified electrical diagram. I reached almost exactly the =20 same solution in designing the power grid for our IV except I have 3 =20 alternators and 3 batteries. Other than that...very similar, big Schotky d= iodes=20 feeding the essential bus from 3 independent electrical systems and the=20 avionics bus powered by two systems, both diode isolated and able to cross= tie to=20 the third. I also have iron gyros, and round airspeed and altimeter backup= =20 instruments. I am no longer young but I have managed to retain my=20 stupidity. I=E2=80=99ve not yet achieved the level of intelligence and mat= urity that you=20 have as I still have aspirations for trans Pacific (and worse, trans=20 Antarctic) flights. Maybe I=E2=80=99ll see you in OZ one day. =20 Bill Harrelson N5ZQ 320 1,950 hrs N6ZQ IV under construction =20 =20 =20 =20 =20 From: _Frederick Moreno_ (mailto:frederickmoreno@bigpond.com)=20 Sent: Thursday, August 04, 2011 9:30 AM To: _lml@lancaironline.net_ (mailto:lml@lancaironline.net)=20 Subject: [LML] Fw: Re: Re-doing my panel - carefully thinking through =20 failures =20 =20 =20 =20 Brent has written much on this topic including "In my "Glazed and =20 Confused" presentation on "Glass Cockpits" I say that flying an aircraft w= ith a=20 non-certified, non TSO'ed glass standby (Dynon et al) is like jumping out = of=20 an airplane with only your main parachute and your standby plan is the fac= t=20 you are wearing real soft socks." =20 I concur.=20 =20 When I was young and stupid (not long ago) I had thoughts of long =20 overwater (think trans-Pacific) flights. I also have experience with fail= ure modes=20 assessment analysis (FMEA) which frequently shows up failure modes easily= =20 over looked. After reviewing various electrical and instrument=20 configurations I arrived at a system design which is shown in simplified f= orm in the=20 attached sketch. It consists of two alternators, two batteries, four=20 busses, and a lot of opportunities for cross tie. I use dual Chelton scre= ens,=20 with PFD off the essential buss (many sources of power), the MFD off of th= e =20 avionics bus (which has many sources of power), and back up electric =20 attitude indicator (on essential buss), turn and bank (essential buss) an= d air=20 speed and altitude indicators. =20 You show me the failure and I can show you the automated or manual work=20 around. And critical stuff is all double protected with circuit breakers = and=20 surge arresters (not shown). =20 But even this diagram is not as safe as it could be. What about something= =20 simple like: a battery relay decides to go flotch? (One already has done= =20 so.) That causes a main bus to go south forcing you to a cross tie=20 solution, not ideal. So not shown are by-pass switches and fuses around t= he =20 relay solenoids I added "just in case" to provide redundancy on all supply= =20 routes. =20 I have a mechanical and electrical fuel pump. And I have an electronic=20 ignition and a magneto. =20 Two of everything, independent power modes, independent pathways, cross=20 connects, multiple layers of electrical spike and surge protection and=20 independent and different principles of gyroscopic display and electrical= power=20 supply. Now one begins to achieve realistically (and defensible) high=20 levels of reliability. =20 =20 If I could only achieve the same with the pilot. =20 Fred Moreno =20 =20 =20 ____________________________________ -- For archives and unsub=20 _http://mail.lancaironline.net:81/lists/lml/List.html_ (http://mail.lancair= online.net:81/lists/lml/List.html)=20 =3D --part1_16cf3.73c7690f.3b6df76f_boundary Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Content-Language: en
Try this
 
http://www= .periheliondesign.com/powerschottkydiodes.htm
 
What, me worry?  ;<}
 
In a message dated 8/5/2011 7:44:36 P.M. Central Daylight Time,=20 colyncase@earthlink.net writes:
= At the=20 risk of topic drift.....I put in those big fat diodes to my essential bus= =20 also.=20
Since them I'm wondering if there's a failure mode on one bus that= =20 crosses the diodes and takes out the other bus.

Colyn

On Aug 5, 2011, at 10:37 AM, Bill Harrelson wrote:
Hi Fred,
 
I like your simplified electrical diagram. I reached almost exactl= y the=20 same solution in designing the power grid for our IV except I have 3=20 alternators and 3 batteries. Other than that...very similar, big Schotk= y=20 diodes feeding the essential bus from 3 independent electrical systems = and=20 the avionics bus powered by two systems, both diode isolated and able t= o=20 crosstie to the third. I also have iron gyros, and round airspeed and= =20 altimeter backup instruments. I am no longer young but I have managed t= o=20 retain my stupidity. I=E2=80=99ve not yet achieved the level of intelli= gence and=20 maturity that you have as I still have aspirations for trans Pacific (a= nd=20 worse, trans Antarctic) flights. Maybe I=E2=80=99ll see you in OZ one d= ay.
 
Bill Harrelson
N5ZQ 320 1,950 hrs
N6ZQ  IV under construction
 
 
 
From: Frederick Moreno
Sent: Thurs= day,=20 August 04, 2011 9:30 AM
To: lml@lancaironline.net
Subject: [L= ML] Fw:=20 Re: Re-doing my panel - carefully thinking through=20 failures
 

--
For archives and unsub http://ma= il.lancaironline.net:81/lists/lml/List.html
=
=3D --part1_16cf3.73c7690f.3b6df76f_boundary--
 
Brent has written much on this topic including "In my "Glaze= d and=20 Confused" presentation on "Glass Cockpits" I say that flying an= =20 aircraft with a non-certified, non TSO'ed glass standby (Dynon et= al)=20 is like jumping out of an airplane with only your main parachute = and=20 your standby plan is the fact you are wearing real soft socks."
 
I concur. 
 
When I was young and stupid (not long ago) I had thoughts of= long=20 overwater (think trans-Pacific) flights.  I also have experi= ence=20 with failure modes assessment analysis (FMEA) which frequently sh= ows=20 up failure modes easily over looked.  After reviewing variou= s=20 electrical and instrument configurations I arrived at a system de= sign=20 which is shown in simplified form in the attached sketch.  I= t=20 consists of two alternators, two batteries, four busses, and a lo= t of=20 opportunities for cross tie.  I use dual Chelton screens, wi= th=20 PFD off the essential buss (many sources of power), the MFD off o= f the=20 avionics bus (which has many sources of power), and back up elect= ric=20 attitude  indicator (on essential buss), turn and bank (esse= ntial=20 buss) and air speed and altitude indicators.
 
You show me the failure and I can show you the automated or= =20 manual work around.  And critical stuff is all double protec= ted=20 with circuit breakers and surge arresters (not shown).
 
But even this diagram is not as safe as it could=20 be.  What about something simple like: a battery relay= =20 decides to go flotch?  (One already has done so.)  That= =20 causes a main bus to go south forcing you to a cross tie solution= , not=20 ideal.  So not shown are by-pass switches and fuses around t= he=20 relay solenoids I added "just in case" to provide redundancy on a= ll=20 supply routes.
 
I have a mechanical and electrical fuel pump.  And I ha= ve an=20 electronic ignition and a magneto.
 
Two of everything, independent power modes, independent path= ways,=20 cross connects, multiple layers of electrical spike and surge=20 protection and independent and different principles of gyroscopic= =20 display and  electrical power supply.  Now one begins t= o=20 achieve realistically (and defensible) high levels of=20 reliability.  
 
If I could only achieve the same with the pilot.
 
Fred Moreno