X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Wed, 18 Jan 2012 06:27:26 -0500 Message-ID: X-Original-Return-Path: Received: from nskntmtas02p.mx.bigpond.com ([61.9.168.140] verified) by logan.com (CommuniGate Pro SMTP 5.4.3) with ESMTP id 5354257 for lml@lancaironline.net; Tue, 17 Jan 2012 19:13:16 -0500 Received-SPF: pass receiver=logan.com; client-ip=61.9.168.140; envelope-from=frederickmoreno@bigpond.com Received: from nskntcmgw08p ([61.9.169.168]) by nskntmtas02p.mx.bigpond.com with ESMTP id <20120118001238.BDDW3825.nskntmtas02p.mx.bigpond.com@nskntcmgw08p> for ; Wed, 18 Jan 2012 00:12:38 +0000 Received: from Razzle ([58.165.11.246]) by nskntcmgw08p with BigPond Outbound id NoCX1i0015JWv5W01oCbox; Wed, 18 Jan 2012 00:12:38 +0000 X-Authority-Analysis: v=2.0 cv=KYJQQHkD c=1 sm=1 a=Ap2HPOVkqcVN/0SrKbfd8g==:17 a=Ycp8Cyn_74AA:10 a=JDadKst33uMA:10 a=8nJEP1OIZ-IA:10 a=wX92sJtnalNmjvTUqNUA:9 a=ZnN51W2sMjkddXk6R9YA:7 a=wPNLvfGTeEIA:10 a=oNHb884J6o8Rp2IGd2wA:9 a=ZpJka5ZO9tP1CrL5d4gA:7 a=Ap2HPOVkqcVN/0SrKbfd8g==:117 MIME-Version: 1.0 X-Original-Message-Id: <4F160E63.000056.01484@RAZZLE> X-Original-Date: Wed, 18 Jan 2012 08:12:19 +0800 Content-Type: Multipart/Alternative; charset="iso-8859-1"; boundary="------------Boundary-00=_JKWYXNW5BHK000000000" X-Mailer: IncrediMail (6244788) From: "Frederick Moreno" X-FID: FLAVOR00-NONE-0000-0000-000000000000 X-Priority: 3 X-Original-To: "Lancair Mail (lml@lancaironline.net)" Subject: Fw: RE: [LML] Steam Gauge Replacement --------------Boundary-00=_JKWYXNW5BHK000000000 Content-Type: Text/Plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable =0D "I=92ve noticed that the term =91spinning mass gyro=92 is being used in t= his discussion, as opposed to =91vacuum driven gyro=92. Does that mean you al= l are comfortable with an electrically driven AI? That would make sense if the = AI contains only contains a simple electric motor which consists of windings and permanent magnets. Those tend to be very tolerant of voltage spikes."= =0D =0D Yup. But.....=0D =0D "But if the electric AI contains even a single electronic component (volt= age regulator, integrated circuit, etc), wouldn=92t that make it vulnerable t= o the same lightning strike that took out my fancy EFIS, charging system, isolating diode, and backup battery?" =0D =0D Aye, and there's the rub with an all electric airplane. (I own one.) =0D =0D Life is full of choices which means you have to make a series of hopefull= y thoughtful decisions. =0D =0D One could choose a vacuum pump and gyro, but history shows that vacuum pu= mps fail frequently, much more frequently than airplanes getting struck with lightning. So I voted to dump the vacuum pump and use an electric AI, and then follow the guidelines of current certified all electric aircraft - d= ual alternators, dual batteries, alternate feed pathways for power, Schottky diode pathways, and I added huge transient suppressors (see Perehelion design). =0D =0D I could not include the lightning protection put in certified aircraft. = So I put big ground lines in to all extremities of the aircraft in an attemp= t to route any passing lighting bolt around the hot side of the electrical system. Nonetheless, there is no question I could get nailed by lightnin= g taking out all the electrical systems. The defense if obvious: if the Stormscope says there is a thunderbumper in the neighborhood, the decisio= n is to leave the neighborhood. That is probably the most important decisi= on of all. =0D =0D I do have a vertical card compass front and center. If the lightning lea= ves that alone, in theory I could use it to keep it pointed in the right direction while I fly the back up steam gages for altitude and airspeed. = I have done so flying VFR while my Cheltons were inoperative due to some GADAHRS work. =0D =0D You pays your money and you takes your choices. You can reduce the risk, but it will never be zero. Thoughtful decisions are very important in th= e risk reduction process.=0D =0D Fred --------------Boundary-00=_JKWYXNW5BHK000000000 Content-Type: Text/HTML; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
 
"I=92ve noticed that the term =91sp= inning mass gyro=92 is being used in this discussion, as opposed to =91va= cuum driven gyro=92. Does that mean you all are comfortable with an elect= rically driven AI? That would make sense if the AI contains only contains= a simple electric motor which consists of windings and permanent magnets= =2E Those tend to be very tolerant of voltage spikes."
 
Yup. But.....
 
"But if the electric AI contains ev= en a single electronic component (voltage regulator, integrated circuit, = etc), wouldn=92t that make it vulnerable to the same lightning strike tha= t took out my fancy EFIS, charging system, isolating diode, and backup ba= ttery?"
 
Aye, and there's the rub with an al= l electric airplane.  (I own one.) 
 
Life is full of choices which = means you have to make a series of hopefully thoughtful decisions.&n= bsp;
 
One could choose a vacuum pump and = gyro, but history shows that vacuum pumps fail frequently, much more freq= uently than airplanes getting struck with lightning. So I voted to dump t= he vacuum pump and use an electric AI, and then follow the guidelines of = current certified all electric aircraft - dual alternators, dual bat= teries, alternate feed pathways for power, Schottky diode pathways, and I= added huge transient suppressors (see Perehelion design).
 
I could not include the lightn= ing protection put in certified aircraft.  So I put big ground lines= in to all extremities of the aircraft in an attempt to route any pa= ssing lighting bolt around the  hot side of the electrical system.&n= bsp; Nonetheless, there is no question I could get nailed by lightning ta= king out all the electrical systems.  The defense if obvious: if the= Stormscope says there is a thunderbumper in the neighborhood, the decisi= on is to leave the neighborhood.  That is probably the most importan= t decision of all.
 
I do have a vertical card compass f= ront and center.  If the lightning leaves that alone, in theory I co= uld use it to keep it pointed in the right direction while I fly the back= up steam gages for altitude and airspeed.  I have done so flying VF= R while my Cheltons were inoperative due to some GADAHRS work.
 
You pays your money and you takes y= our choices.  You can reduce the risk, but it will never be zer= o.  Thoughtful decisions are very important in the risk reduction pr= ocess.
 
Fred
=
 
--------------Boundary-00=_JKWYXNW5BHK000000000--