X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from fmailhost04.isp.att.net ([207.115.11.54] verified) by logan.com (CommuniGate Pro SMTP 6.0c3) with ESMTP id 5930307 for flyrotary@lancaironline.net; Sun, 09 Dec 2012 08:21:27 -0500 Received-SPF: none receiver=logan.com; client-ip=207.115.11.54; envelope-from=bbradburry@bellsouth.net Received: from desktop (adsl-98-85-189-141.mco.bellsouth.net[98.85.189.141]) by isp.att.net (frfwmhc04) with SMTP id <20121209132051H0400ap99oe>; Sun, 9 Dec 2012 13:20:52 +0000 X-Originating-IP: [98.85.189.141] From: "Bill Bradburry" To: "'Rotary motors in aircraft'" References: In-Reply-To: Subject: RE: [FlyRotary] Re: Engine Ground changed from Aeroquip hose Date: Sun, 9 Dec 2012 08:20:53 -0500 Message-ID: <9DFF1A4BE0AF43AABC20476414149F17@Desktop> MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0009_01CDD5E6.1B92EAE0" X-Mailer: Microsoft Office Outlook 11 Thread-Index: Ac3VupjuDSKkb5AFSaqJyWq5jSQ/NQAU8xsA X-MimeOLE: Produced By Microsoft MimeOLE V6.0.6002.18463 This is a multi-part message in MIME format. ------=_NextPart_000_0009_01CDD5E6.1B92EAE0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Steve, You are correct that there is a commonality. So far everything is on the endurance buss. Also I have disassembled the forest of tabs and am cleaning it up and will do the same for the battery connections. The wires coming to the forest of tabs looks like a rats nest, so I am going to at least dress it up a little. I have previously replaced both the power and ground wires to the transponder. I may replace the ground wires to the other "victims" when I dress up the ground wires. I have never seen any voltage fluctuations incoming to the transponder when it craps out. At first, I thought it was getting hot and shutting down, but if it does get hot, it is supposed to just reduce the frequency of response to interrogations. I pulled it out and took it to a radio shop. They put it on their bench for two days and it never shut down. It is something in my plane but I haven't found it yet. My annual is due in Jan. I will replace the Aeroquip fuel hose then. Looks like I will not be doing much flying in between. B2 _____ From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Steven W. Boese Sent: Saturday, December 08, 2012 10:09 PM To: Rotary motors in aircraft Subject: [FlyRotary] Re: Engine Ground changed from Aeroquip hose Bill, You are correct that my battery is in the cockpit. Since you have multiple devices that are having problems simultaneously, it might be good to check things that are common to all of them. The likelihood of loosing several ground or supply connections at the same time seems remote. In other words, check the connection of the forest of tabs to the battery ground before worrying about the individual tabs.. Also, since you have two batteries, it seems unlikely that the problem would be happening within both of them at the same time. Are the batteries connected to the positive side of the system through separate contactors? If so, are both contactors closed when the problem occurs? If both batteries are connected through one contactor, that could be a common point of failure. Steve _____ From: Rotary motors in aircraft [flyrotary@lancaironline.net] on behalf of Bill Bradburry [bbradburry@bellsouth.net] Sent: Saturday, December 08, 2012 6:06 PM To: Rotary motors in aircraft Subject: [FlyRotary] Engine Ground changed from Aeroquip hose Steve, My two batteries are mounted on the engine side of the firewall. I presume yours is mounted in the cockpit? I had not considered a loose connection inside the battery. I plan to clean up all the connections outside the battery. I have had a VOM connected to the supply side of the transponder when it went off and I did not see any fluctuation in the voltage when that happened. Several folks have suggested that I have a grounding issue so I am cleaning all of them up. I previously replaced both the power and ground wires to the transponder but that had no affect. I am not certain how to check each ground wire going to the forest of tabs. Anybody have a suggestion? Bill B _____ From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Steven W. Boese Sent: Saturday, December 08, 2012 4:52 PM To: Rotary motors in aircraft Subject: [FlyRotary] Re: Aeroquip hose Bill, From your description, your ground architecture sounds very similar to mine. I have the forest of tabs bolted to the firewall with a brass bolt. On the cabin side, the battery ground is connected to this bolt. Everything else grounds to the forest of tabs. On the engine side of the firewall, the engine ground is connected from the front (in the car) cover to that brass bolt. My arrangement has not had any electrical problems that I am aware of. I also have a stainless wire braid covered fuel line from the firewall bulkhead fitting to the fuel rail on the engine. I have seen no damage to it. The fact that your wire braid on the fuel line has been burnt suggests that it might have intermittently served as the engine ground at one time or another. The braid must not have conducted a large current for very long or it would been destroyed completely. I can't think of a worse place to have an uncontrolled resistance heater than on that fuel line. Verifying the integrity of the ground from the engine to the airframe and from the battery to the airframe certainly seems like a worthwhile endeavor. Depending on the details of the alternator installation, an intermittent connection inside the battery also might be a possibility although this would not explain the damage to the fuel line braid. FWIW Steve Boese RV6A, 1986 13B NA, RD1A, EC2 ------=_NextPart_000_0009_01CDD5E6.1B92EAE0 Content-Type: text/html; charset="us-ascii" Content-Transfer-Encoding: quoted-printable

Steve,

You are correct that there is a commonality.  So far everything is on the endurance buss.  = Also I have disassembled the forest of tabs and am cleaning it up and will do the = same for the battery connections.  The wires coming to the forest of tabs = looks like a rats nest, so I am going to at least dress it up a little.  = I have previously replaced both the power and ground wires to the transponder.  I may = replace the ground wires to the other “victims” when I dress up the = ground wires.

 

I have never seen any voltage = fluctuations incoming to the transponder when it craps out.  At first, I thought = it was getting hot and shutting down, but if it does get hot, it is supposed to = just reduce the frequency of response to interrogations.  I pulled it = out and took it to a radio shop.  They put it on their bench for two days = and it never shut down.

 

It is something in my plane but I = haven’t found it yet.

 

My annual is due in Jan.  I = will replace the Aeroquip fuel hose then.  Looks like I will not be = doing much flying in between.

 

B2

 

From: = Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Steven W. Boese
Sent: Saturday, December = 08, 2012 10:09 PM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: = Engine Ground changed from Aeroquip hose

 

Bill,

 

You are correct that my battery is in = the cockpit.  Since you have multiple devices that are having problems simultaneously, it might be good to check things that are common to all = of them.  The likelihood of loosing several ground or supply connections at the same time seems remote.  In other words, check = the connection of the forest of tabs to the battery ground before worrying about the individual tabs..  Also, since you = have two batteries, it seems unlikely that the problem would be = happening within both of them at the same time.  Are the batteries connected to the positive side of the system through separate contactors?  If so, are both contactors closed when the problem occurs?  = If both batteries are connected through one contactor, that could be a = common point of failure. 

 

Steve      =    

From: = Rotary motors in aircraft [flyrotary@lancaironline.net] on = behalf of Bill Bradburry = [bbradburry@bellsouth.net]
Sent: Saturday, December = 08, 2012 6:06 PM
To: Rotary motors in aircraft
Subject: [FlyRotary] = Engine Ground changed from Aeroquip hose

Steve,

 

My two batteries are mounted on the = engine side of the firewall.  I presume yours is mounted in the = cockpit?  I had not considered a loose connection inside the battery.  I plan = to clean up all the connections outside the battery.

I have had a VOM connected to the = supply side of the transponder when it went off and I did not see any = fluctuation in the voltage when that happened.  Several folks have suggested that = I have a grounding issue so I am cleaning all of them up.  I previously = replaced both the power and ground wires to the transponder but that had no = affect.

 

I am not certain how to check each = ground wire going to the forest of tabs.  Anybody have a = suggestion?

 

Bill B

 

From: Rotary motors in = aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Steven W. Boese
Sent: Saturday, December = 08, 2012 4:52 PM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: = Aeroquip hose

 

Bill,

 

From your description, your ground architecture sounds very similar to mine.  I have the forest of tabs bolted to the firewall with a brass bolt.  On the = cabin side, the battery ground is connected to this bolt.  Everything else = grounds to the forest of tabs.  On the engine side of the firewall, the engine = ground is connected from the front (in the car) cover to that brass bolt.  My arrangement has not had any electrical problems that = I am aware of.

 

I also have a stainless wire braid = covered fuel line from the firewall bulkhead fitting to the fuel rail on the = engine.  I have seen no damage to it.  The fact that your wire braid on the = fuel line has been burnt suggests that it might have intermittently served as = the engine ground at one time or another.  The braid must not have = conducted a large current for very long or it would been destroyed completely.  = I can't think of a worse place to have an uncontrolled resistance heater = than on that fuel line.  Verifying the integrity of the ground from the = engine to the airframe and from the battery to the airframe certainly seems like a worthwhile endeavor.

 

Depending on the details of the = alternator installation, an intermittent connection inside the battery also might = be a possibility although this would not explain the damage to the fuel line = braid.

 

FWIW

 

Steve Boese

RV6A, 1986 13B NA, RD1A, = EC2

       = ; 

 

 

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