---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Wed 02/21/07: 19 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 05:58 AM - P-mags and the RV-7 Off Field Landing (Robert L. Nuckolls, III) 2. 06:00 AM - Re: Stripping Longer Piece of Shielded/Twisted Pair Wire (Robert L. Nuckolls, III) 3. 06:50 AM - Re: P-mags (Hinde, Frank George (Corvallis)) 4. 06:53 AM - Re: P-mags and the RV-7 Off Field Landing (BobsV35B@aol.com) 5. 07:15 AM - Engine gage wiring (Danm) 6. 08:06 AM - Re: Engine gage wiring (Mike) 7. 08:30 AM - Re: P-mags (Kevin Horton) 8. 09:22 AM - Re: Engine gage wiring (Robert L. Nuckolls, III) 9. 09:54 AM - Re: Engine gage wiring (Danm) 10. 09:56 AM - Re: Full Auto (marcausman) 11. 10:15 AM - Re: Re: Engine gage wiring (Dale Ensing) 12. 10:19 AM - Re: Re: Engine gage wiring (Hinde, Frank George (Corvallis)) 13. 12:24 PM - Re: Strobes (C Smith) 14. 12:44 PM - Re: Re: Full Auto () 15. 06:36 PM - 28v switches in a 12v system? (Chris Johnston) 16. 07:23 PM - Re: 28v switches in a 12v system? (Robert L. Nuckolls, III) 17. 08:05 PM - Re: 28v switches in a 12v system? (Matt Prather) 18. 08:09 PM - Re: P-mags (Robert L. Nuckolls, III) 19. 10:29 PM - Re: P Mags (Speedy11@aol.com) ________________________________ Message 1 _____________________________________ Time: 05:58:54 AM PST US From: "Robert L. Nuckolls, III" Subject: AeroElectric-List: P-mags and the RV-7 Off Field Landing At 01:43 AM 2/21/2007 +0000, you wrote: > >Frank, > >Help me out here, if that isn't a "failure", just what would you call >it? In my book, any mechanical screw up that causes an unplanned landing >sure fits the definition of a failure. No doubt there WAS a SYSTEM failure. But accurate investigation and diagnosis of root cause extends FAR beyond what usually happens when unhappy events in aviation spark public discussions. It's inarguable that the pilot perceived a reason to make an off-field landing. Anecdotally, we understand that the ignition SYSTEM was misbehaving. What do we know about how the pilot reacted to his/her perceptions? What did your instructor tell you to do when the engine is running badly? Were there not words suggesting that turning the mags off one at a time would help you isolate a recalcitrant magneto? Is it not reasonable to expect that a similar investigation would have been useful in this event? What do you think the probability is that both Emagair products became unserviceable on the same tank full of fuel? What do we know about the post flight discovery of facts? I think the major point to be considered here is that the general public is very quick to launch lengthy and heated debate on a variety of non-news items reported in the media. I say "non-news" because while the stories may accurately record a happening, the reporter rarely knows diddly-squat about the simple-ideas that underlie the story. They're prone to rely on the words of others who are probably as ignorant of facts and understanding as the reporter is. In Chapter 17 of the 'Connection I've suggested that the pilot subsystem is subordinate only to the airframe in importance for having a happy ending to an aviation experience. Those of us who have lived and worked in the aviation venue most of our careers are skeptical of the notion that the aircraft featured in this story suffered an ignition system failure that would be expected to force an off-field landing. But lacking more data, the best we can offer is a considered opinion as to PROBABILITY based on our past experience. Opinions not founded in simple-ideas and offered by individuals who cannot teach the significance of those ideas are suspect. This is where the differences between teachers and propagandists become strikingly obvious. So before we get out the big brush and red paint and write ACCIDENT INDUCING FAILURE across E-Magair's reputation, let us take the time on THIS LIST to conduct careful consideration of facts. It's unlikely that you'll get any facts from folks who were not there and did not put their hands on hardware. So no matter what pot is boiling on any other List, let us do the science (and/or rely on others who ARE doing the science) lest we give rise to invariably poor recommendations that arise from equally poor conclusions. Bob . . . ________________________________ Message 2 _____________________________________ Time: 06:00:59 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Stripping Longer Piece of Shielded/Twisted Pair Wire At 10:48 PM 2/20/2007 -0600, you wrote: >I have a few electrical cables (e.g., from nav lights) to my panel that >are shielded/twisted pairs. One of the wires goes to the panel switch and >the other goes to the ground block on the firewall. Is there any easy way >to strip of 2' to 3' of the outer cable jacket so I can reach both the >switch and the ground block without splicing in a piece of wire to run to >the ground block? You have a ground block located adjacent to the switches? Interesting. In answer to your question, try a pair of cuticle scissors, the slim points can be pushed under the jacket and between the twisted wires far enough to allow the shears to cut the jacket away. Obviously, this doesn't work on single conductor cable. Bob . . . ---------------------------------------- ( IF one aspires to be "world class", ) ( what ever you do must be exercised ) ( EVERY day . . . ) ( R. L. Nuckolls III ) ---------------------------------------- ________________________________ Message 3 _____________________________________ Time: 06:50:51 AM PST US Subject: RE: AeroElectric-List: P-mags From: "Hinde, Frank George (Corvallis)" Fair point Harry, I guess my conjecture was that one of the P mags could have been turned off and the engine would have resumed normal operation...I just wish I'd though of it when it happened to me...Of course my engine just ran hot, i.e did not causean engine stoppage. Frank -----Original Message----- From: owner-aeroelectric-list-server@matronics.com [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of HCRV6@comcast.net Sent: Tuesday, February 20, 2007 5:43 PM Subject: RE: AeroElectric-List: P-mags Frank, Help me out here, if that isn't a "failure", just what would you call it? In my book, any mechanical screw up that causes an unplanned landing sure fits the definition of a failure. -- Harry Crosby RV-6 N16CX, 312 hours -------------- Original message ---------------------- From: "Hinde, Frank George (Corvallis)" (Corvallis)" > > > Nope Dual P mags. They did NOT fail. I believe ONE of them went to > very advanced timing. It has the effect of fouling up the timing > completely because once the charge has been lit the second spark > doesn't do anything. > > There is a long discussion on the Vansairforce website about it. > > Frank > RV-7a > > -----Original Message----- > From: owner-aeroelectric-list-server@matronics.com > [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of > John W. Cox > Sent: Tuesday, February 20, 2007 11:54 AM > To: aeroelectric-list@matronics.com > Subject: RE: AeroElectric-List: P-mags > > --> > > I was not aware the four cylinder P mag was yet available for Prime > Time. Could this have been dual E mags? > > John Cox > > > > -----Original Message----- > From: owner-aeroelectric-list-server@matronics.com > [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of > Terry Watson > Sent: Tuesday, February 20, 2007 10:47 AM > To: aeroelectric-list@matronics.com > Subject: AeroElectric-List: P-mags > > > > > This is an excerpt from a message to the Matronics Engines list this > morning, posted by Mike Larkin: > > " As for the P-mag, I recovered an RV-7 from a highway two weekends > ago when Both P-mags failed. Guess what, the electrical system worked > perfectly......" > > Since E-mags and P-mags have been a subject on this list, I thought I > would pass it on. Does anyone know the story? > > Terry > > > > > > > > > > > > > > > > > > > > ________________________________ Message 4 _____________________________________ Time: 06:53:01 AM PST US From: BobsV35B@aol.com Subject: Re: AeroElectric-List: P-mags and the RV-7 Off Field Landing In a message dated 2/21/2007 8:01:18 A.M. Central Standard Time, nuckollsr@cox.net writes: So before we get out the big brush and red paint and write ACCIDENT INDUCING FAILURE across E-Magair's reputation, let us take the time on THIS LIST to conduct careful consideration of facts. It's unlikely that you'll get any facts from folks who were not there and did not put their hands on hardware. So no matter what pot is boiling on any other List, let us do the science (and/or rely on others who ARE doing the science) lest we give rise to invariably poor recommendations that arise from equally poor conclusions. Bob . . . Good Morning 'Lectric Bob, I realize we are not supposed to post Me Too or other confirmation messages, but you have hit the nail so squarely that I just cannot resist. Great post! Do Not Archive! Happy Skies, Old Bob AKA Bob Siegfried Ancient Aviator Stearman N3977A Brookeridge Air Park LL22 Downers Grove, IL 60516 630 985-8503


**************************************
Check out free AOL at http://free.aol.com/thenewaol/index.adp. Most comprehensive set of free safety and security tools, millions of free high-quality videos from across the web, free AOL Mail and much more. ________________________________ Message 5 _____________________________________ Time: 07:15:05 AM PST US Subject: AeroElectric-List: Engine gage wiring From: "Danm" I installed a UMA oil pressure gage, PN 4-210-080 and a oil temp gage, PN 12-200-250f in my Kitfox IV with a Jabiru 2200 engine. When I open the master switch (split rocker), the gages have readings of approximately 25 psi oil pressure and 120 degree oil temp. The engine hasn't been started yet (new aircraft), so there must be something wrong with the wiring or the sending units supplied with the engine. I check the gage wiring and looks to be correct. I suspect either a wiring issue or a sending unit issue. I you can help me out, it would be appreciated. Thanks in advance -------- Dan Mc Intyre Kitfox Model IV, Jab 2200 Read this topic online here: http://forums.matronics.com/viewtopic.php?p'487#96487 ________________________________ Message 6 _____________________________________ Time: 08:06:13 AM PST US From: "Mike" Subject: RE: AeroElectric-List: Engine gage wiring Dan, Check all of your grounds. Make sure the engine is grounded to the airframe. Make sure that the instrument is grounded to the main ground (airframe)or ground bus. Make sure you have a large enough ground from the engine to the airframe. Just my thoughts, Mike Larkin -----Original Message----- From: owner-aeroelectric-list-server@matronics.com [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Danm Sent: Wednesday, February 21, 2007 8:14 AM Subject: AeroElectric-List: Engine gage wiring I installed a UMA oil pressure gage, PN 4-210-080 and a oil temp gage, PN 12-200-250f in my Kitfox IV with a Jabiru 2200 engine. When I open the master switch (split rocker), the gages have readings of approximately 25 psi oil pressure and 120 degree oil temp. The engine hasn't been started yet (new aircraft), so there must be something wrong with the wiring or the sending units supplied with the engine. I check the gage wiring and looks to be correct. I suspect either a wiring issue or a sending unit issue. I you can help me out, it would be appreciated. Thanks in advance -------- Dan Mc Intyre Kitfox Model IV, Jab 2200 Read this topic online here: http://forums.matronics.com/viewtopic.php?p'487#96487 -- 2/8/2007 -- 2/8/2007 ________________________________ Message 7 _____________________________________ Time: 08:30:40 AM PST US From: Kevin Horton Subject: Re: AeroElectric-List: P-mags On 21 Feb 2007, at 09:49, Hinde, Frank George (Corvallis) wrote: > (Corvallis)" > > Fair point Harry, > > I guess my conjecture was that one of the P mags could have been > turned > off and the engine would have resumed normal operation...I just > wish I'd > though of it when it happened to me...Of course my engine just ran > hot, > i.e did not causean engine stoppage. > It is too much to expect for you to suddenly become very bright after the incident occurs, and decide to try turning one ignition off. It is far better to put that step in your Rough Running Engine and Engine Failure checklists now. Then, whenever the problem occurs, the fact that you are familiar with your emergency checklist should hopefully trigger you to try turning one ignition off at a time. Kevin Horton RV-8 (Finishing Kit) Ottawa, Canada http://www.kilohotel.com/rv8 ________________________________ Message 8 _____________________________________ Time: 09:22:50 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Engine gage wiring At 07:14 AM 2/21/2007 -0800, you wrote: > >I installed a UMA oil pressure gage, PN 4-210-080 and a oil temp gage, PN >12-200-250f in my Kitfox IV with a Jabiru 2200 engine. When I open the >master switch (split rocker), the gages have readings of approximately 25 >psi oil pressure and 120 degree oil temp. The engine hasn't been started >yet (new aircraft), so there must be something wrong with the wiring or >the sending units supplied with the engine. I check the gage wiring and >looks to be correct. I suspect either a wiring issue or a sending unit >issue. I you can help me out, it would be appreciated. > >Thanks in advance Without knowing details of the internal workings for these instruments, I'll offer the following hypothesis to explain what you're observing: The earliest PRECISION (meaning stable and repeatable) instruments were crafted from a coil of wire suspended in a magnetic field where a current impressed on the coil would force rotation against a spring and move a pointer upscale. This is known as the D'Arsonval meter movement. http://www.triquartz.co.uk/ammeter.html Similar devices had moving magnets held at "zero" by a spring and suspended in a single fixed coil. Both of these technologies feature a return spring that causes the instrument to assume a familiar and expected "zero" reading when powered down. Modern instruments have worked past some of the manufacturing problems with legacy designs. A very popular, robust and inexpensive design is also moving magnet. But instead of one coil, there are two coils at right angles to each other. When the two coils are energized, the magnet (free to move 360 degrees) will assume alignment with the magnetic field generated by the two coils. This technology allows a designer to produce instruments having very small rotational arcs . . . up to and including 360 continuous degrees without stops. These movements do not have or need return springs. Therefore, the position assumed by the pointer in a powered down condition may be random and unpredictable unless the designer takes special pains with driving circuitry to make the instrument indicate "zero" when powered down. Given the popularity of this technology and the very reasonable cost to manufacture, I'll bet that what you're seeing is the predictable behavior of a 4-quadrant, moving magnet movement during power down. As long as the instrument is reading correctly when powered up, there's no reason to be concerned. Bob . . . For further reading see: http://www.jewellinstruments.com/pmtheory101.htm http://www.jewellinstruments.com/pmglossary.htm ________________________________ Message 9 _____________________________________ Time: 09:54:03 AM PST US Subject: AeroElectric-List: Re: Engine gage wiring From: "Danm" I ment to say that the gages are at zero with no power applied, when I power up thats when the gages go to the 25psi and 120 degree reading, engine not running. What do you think??? Thanks for the help -------- Dan Mc Intyre Kitfox Model IV, Jab 2200 Read this topic online here: http://forums.matronics.com/viewtopic.php?p'519#96519 ________________________________ Message 10 ____________________________________ Time: 09:56:12 AM PST US Subject: AeroElectric-List: Re: Full Auto From: "marcausman" Sam, Take a look at www.verticalpower.com . It will load shed and switch alternators (nearly) automatically, and meet your KISS principles for wiring. Won't be available until August though. Marc -------- Marc Ausman http://www.verticalpower.com RV-7 IO-390 Flying Read this topic online here: http://forums.matronics.com/viewtopic.php?p'520#96520 ________________________________ Message 11 ____________________________________ Time: 10:15:57 AM PST US From: "Dale Ensing" Subject: Re: AeroElectric-List: Re: Engine gage wiring Dan, I remember getting an obviously erronous number on my oil pressure when system was first turn on. Solved the problem by reversing the leads connection at the sending unit. The sending unit had no indication of polarity so initial connection was a 50% guess. Dale Ensing ----- Original Message ----- From: "Danm" Sent: Wednesday, February 21, 2007 12:52 PM Subject: AeroElectric-List: Re: Engine gage wiring > > I ment to say that the gages are at zero with no power applied, when I > power up thats when the gages go to the 25psi and 120 degree reading, > engine not running. What do you think??? Thanks for the help > > -------- > Dan Mc Intyre > Kitfox Model IV, Jab 2200 > > > Read this topic online here: > > http://forums.matronics.com/viewtopic.php?p'519#96519 > > > ________________________________ Message 12 ____________________________________ Time: 10:19:25 AM PST US Subject: RE: AeroElectric-List: Re: Engine gage wiring From: "Hinde, Frank George (Corvallis)" Either the wrong senders for the guages or a bad ground between the sender and the guages. Worng senders happen quite often. Call the supplier and ask them what the resistnace curve looks like, i.e get the resistance for say 55F and measure resistance with your multimeter. Frank -----Original Message----- From: owner-aeroelectric-list-server@matronics.com [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Danm Sent: Wednesday, February 21, 2007 9:53 AM Subject: AeroElectric-List: Re: Engine gage wiring I ment to say that the gages are at zero with no power applied, when I power up thats when the gages go to the 25psi and 120 degree reading, engine not running. What do you think??? Thanks for the help -------- Dan Mc Intyre Kitfox Model IV, Jab 2200 Read this topic online here: http://forums.matronics.com/viewtopic.php?p'519#96519 ________________________________ Message 13 ____________________________________ Time: 12:24:01 PM PST US From: "C Smith" Subject: RE: AeroElectric-List: Strobes -----Original Message----- From: owner-aeroelectric-list-server@matronics.com [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Fergus Kyle Sent: Monday, February 19, 2007 5:05 PM Subject: AeroElectric-List: Strobes >>Craig, I read your latest paragraph regarding lighting and noted that's it's all "I" and no "we". Manoeuvring around an airfield, particularly a busy one, is very much a community thing, not a solitary event.<< (I) speak for my self, therefore (I) don't use the term we. (I) don't see anyone else using "we" when writing about themselves. Silly issue to pick on. >> While you are not bothered by another's strobes on the tarmac, many others are, me included. If you were to sit up at 20 feet in Chicago O'Hare and every aircraft had on strobes, you would appreciate the confusion and wariness that occurred.<< While (I)'m sure people get bothered by lots of things, I can't accommodate everyone's peeve. (I) don't intend to fly into O'Hare and I wouldn't use strobes at a busy controlled airport for taxi. My airport is uncontrolled, and after the events mentioned, (I) determined (I) prefer to be seen. >> Strobes don't quickly indicate speed, turns or direction. That's why we copied ships and used coloured lamps - which do all three. Trying to guess the progress of conflicting traffic between flashes is a mug's game and unsafe. It is unnecessarily distracting and time-wasting when time's in short supply.<< (I) would challenge all of what you have written. The lighting (on aircraft) was adopted long before strobes were in existence, and strobes are used to capture (photography) and simulate motion (the rabbit on instrument approach lighting) all the time. Please cite some professional study for this claim. While observing aircraft (I) have had no trouble discerning their motion with strobes on, and can clearly see their other running lights in spite of the strobes. Against a static background motion is clearly accentuated by stroboscopic effect, giving both direction and speed, the latter most precisely. >> Strobes are designed to be seen many miles away, not several feet.<< (I) beg to differ, the factory in which (I) work employs strobes on all autonomous vehicles that operate there, and (I) believe it is an OSHA requirement. The distances are measured in feet, from where these vehicles operate and people work. The strobes make them virtually unmistakable. So strobes are not distance limited. >> Turning strobes on at Take-off clearance tells everyone who's the primary traffic on the live runway, and the tower that the clearance has been received and acted on.... and it does so without bothering anyone. If the clearance wasn't issued, it draws attention to the tower that danger is building and the take-off stopped if possible.<<< First (I)'ve heard of this connection, it was not taught in my instrument work. Please cite the appropriate FAR/AIM entry. (I) don't find the reasoning for this one as unfounded as the other claims, it actually makes some sense. If this is truly an ATC procedure (I) would like to read that in an official document. >>>"I'm sure the flames will start, and the name calling will follow, but I'd rather be an a*****e than an accident statistic." Safe, co-ordinated airport traffic is not necessarily about what you'd rather be. It's more concerning about what you'd rather not cause.<<< (I)'d love to see an accident report from the NTSB, or the FAA citing "inappropriate or illegal use of strobes" as either a cause or contributing factor of an accident. You will of course send me a link. >> Turning landing lights on descent through 10.000 feet is not about aircraft collisions, it's training bird flocks to avoid aircraft. Ferg Kyle Europa A064 914 Classic PS: I think the argument for rotating beacons has more merit.<< This one escapes me, pardon my misunderstanding. This is tongue in cheek? Or a serious entreaty on use of lights. You are entitled to your opinion, (I) respect your civil and creative discourse, but give me facts, and (I) will then make a considered change of mind. Craig Smith ________________________________ Message 14 ____________________________________ Time: 12:44:51 PM PST US From: Subject: Re: AeroElectric-List: Re: Full Auto Yea, that's a great idea, but I can't until Summer, I hope to fly on the next few weeks! ---- marcausman wrote: > > Sam, Take a look at www.verticalpower.com . It will load shed and switch alternators (nearly) automatically, and meet your KISS principles for wiring. Won't be available until August though. > > Marc > > -------- > Marc Ausman > http://www.verticalpower.com > RV-7 IO-390 Flying > > > > > Read this topic online here: > > http://forums.matronics.com/viewtopic.php?p'520#96520 > > > > > > > > > > ________________________________ Message 15 ____________________________________ Time: 06:36:47 PM PST US Subject: AeroElectric-List: 28v switches in a 12v system? From: "Chris Johnston" Alright smart guys... here's my dumb question of the day... Can I use LED illuminated switches designed for a 28 volt system in a 12 volt system? Why or why not? What would theoretically happen? I imagine that I'm fully displaying my lack of understanding in this area, but try to be gentle. Thanks! cj ________________________________ Message 16 ____________________________________ Time: 07:23:02 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: 28v switches in a 12v system? At 06:32 PM 2/21/2007 -0800, you wrote: > > >Alright smart guys... here's my dumb question of the day... > >Can I use LED illuminated switches designed for a 28 volt system in a 12 >volt system? Why or why not? What would theoretically happen? I >imagine that I'm fully displaying my lack of understanding in this area, >but try to be gentle. Sure, they'll just be dim compared to the 14v illumination level. Better get one, hook it to a battery and see if the illumination level is still satisfactory to your needs. Bob . . . ---------------------------------------- ( IF one aspires to be "world class", ) ( what ever you do must be exercised ) ( EVERY day . . . ) ( R. L. Nuckolls III ) ---------------------------------------- ________________________________ Message 17 ____________________________________ Time: 08:05:57 PM PST US Subject: Re: AeroElectric-List: 28v switches in a 12v system? From: "Matt Prather" It won't hurt anything, but they'll be dimmmer. LED's like most diodes have very non-linear current vs. voltage curves. Below the knee voltage the current is nearly zero. Once the voltage goes above gets above the knee, the current increases rapidly for small increases in voltage. A typicl LED knee voltage is about 1.5V. Changing from 28V to 12V will still keep the voltage applied to the LED above the knee voltage. For the purposes of your question, let's assume that for both 12V and 28V the voltage across the LED is 1.7V - a safe assumption, though not perfectly accurate. Let's also assume that the current through the LED at 28V was 20mA. That says the switch has a dropping resistor with a value given by R = V/I (28V - 1.7V) /20mA = 1315ohm. Next, let's calculate the current through the circuit when running with a 12V supply. I = V/R = (12V - 1.8V) / 1315ohm = 7mA When considering light output, the key is about power. Let's compare. P(28V) = 20mA * 1.7V = 34mW P(12V) = 7mA * 1.7V = 12mW So, I would expect that when running the 28V switches at 12V, the emitted light would be about one third. Maybe less, actually. At the lower current, the voltage drop across the diode is going to be a little less, so the power is going to be a little less too. At 1.5V the power is 10.5mW. Hope that helps.. Regards, Matt- > > > Alright smart guys... here's my dumb question of the day... > > Can I use LED illuminated switches designed for a 28 volt system in a 12 > volt system? Why or why not? What would theoretically happen? I > imagine that I'm fully displaying my lack of understanding in this area, > but try to be gentle. > > Thanks! > cj > > ________________________________ Message 18 ____________________________________ Time: 08:09:45 PM PST US From: "Robert L. Nuckolls, III" Subject: RE: AeroElectric-List: P-mags At 02:49 PM 2/21/2007 +0000, you wrote: > > >Fair point Harry, > >I guess my conjecture was that one of the P mags could have been turned >off and the engine would have resumed normal operation...I just wish I'd >though of it when it happened to me...Of course my engine just ran hot, >i.e did not causean engine stoppage. > >Frank Since this is a failure mode unique to the e/p-mag products, perhaps words to guide the pilot in conducting an in-flight diagnosis and remedy should be added to the POH for any aircraft that carries one or more Emagair products. Bob . . . ________________________________ Message 19 ____________________________________ Time: 10:29:34 PM PST US From: Speedy11@aol.com Subject: AeroElectric-List: Re: P Mags The initial info I have is that one P Mag advanced the timing too far resulting in power loss since the fuel/air mixture was ignited as in entered the cylinder. During a power loss, the pilot should cycle the ignition source to left/right/both to check for any improvement. The P Mags don't revert to the internal generator until electrical power is lost. Since electrical power was available, a P Mag would not revert to the backup mode, so that means when the faulty ignition is turned off, the engine would run normally again. Initial indications are the pilot did not cycle the ignitions through left/right. I will be interesting to see what Brad discovers. Stan Sutterfield Nope Dual P mags. They did NOT fail. I believe ONE of them went to very advanced timing. It has the effect of fouling up the timing completely because once the charge has been lit the second spark doesn't do anything. ------------------------------------------------------------------------------------- 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.