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E-Mag P-Mag Safety info - Referenced msg from Mr. Cotner

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steve(at)tomasara.com
Guest

Posted: Sun Sep 14, 2008 3:21 pm Post subject: E-Mag P-Mag Safety info - Referenced msg from Mr. Cotner

************ Forwarded from Canard Aviators list ****************

Fellow fliers,

I received this from a friend on the Bearhawk owners group.  I have no 

dog in

this fight but feel it is important for everyone to be aware of.



Ric Lee

Sandy, Utah

--------------------------------------------------------------------------------\

--------------------------------------

Received this as a forward to the Bearhawk group.

My name is Gary Cotner  Until

August 11th I had flown my Thorp T-18 N57GC for twenty years and 1500

hours without any problems.  That all changed.  Story to

follow.  I will try to keep it very factual and objective.



To all the people on the list and any of the people that you might know

that fly with E-MAG or P-MAG on their planes. I want every body to

forward this to all concerned. I want this to get out to the aviation

community at large.   I am going to tell what happened to

me.



I bought two P-MAGS from E-MAG and put them on the plane prior to going

to OSH this year.  Flew to OSH and had a good time as usual. 

On the trip home about 45 minutes out the engine started having an

intermittent miss.  Was going to Kirksville, MO  for

fuel,  decided to divert to Iowa City, IA.  Good thing I did I

almost didn't make it.  Had to dead stick land there.



The left P-MAG had failed completely and the right one was

intermittent.  I called the E-MAG people and they sent me an E-MAG

and P-MAG to replace the defective ones.  Put them on and ran the

tests 6 times and all was well.  Full power runs and mag checks went

well.  Took off and at about 800 agl the engine started running so

rough that I wasn't sure it would maintain altitude.  From the past

experience I needed to get the plane back on the ground before the engine

failed completely. Turned back to runway and was way high to land,

slipped and still running out of room to land.  Had to divert to a

closed runway and still short on room got too slow and pancaked in and

totaled the plane.  This all because of the E-MAG failures.



I called these people about the crash and they were very nonchalant about

the problem.  Said they weren't sure that I in fact had this

failure.  Invited them to come to my place and I would run the

Engine for them. to prove the problem.  It has been 8 days since I

asked for an answer and no response.  I am going to call tomorrow

for an answer as to why they haven't answered my call.



The plane is still in good enough condition to run the engine.  I

have since done this and the E-MAG is intermittent and the engine will

back fire when the E-MAG is not firing at its proper time.  When

these units fail they can fire at random and cause the engine to quit.

The stress imposed on the crankshaft is very hard and needs to be

addressed as an issue like a sudden stoppage.



I reference Dave's comments below and highly recommend that you GROUND

YOUR plane until you put an other ignition system on it.  In other

words don't fly it with E-MAGS or P-MAGS on it.  I don't want to see

anyone die because of these units as they have an inherent design

flaw. 



The fix that they describe is not a good one,roll pins are very brittle

and subject shattering. plus drilling a hole in the shaft creates a

stress riser  and can lead to failure of the shaft.



The shaft should not be able to move at all,  the sensor should be

keyed to the shaft.



This item should be removed from the market in it's present design.



 ===============================================================================\

===



All aircraft that are flying with it need to be grounded until they have

a different system on them



I think those of you who are running E-mag products need to be aware

of my experience over the weekend.  I am running dual P-mags on my

plane.  On the return trip from Waco, TX I developed a rough running

engine in cruise at altitude.  At first it was just an occasional

miss or it felt as if the engine was surging slightly.  As time went

on the engine ran progressively rougher.  Carb heat had no

effect.  Mag check, right is fine, engine nearly dies on the

left.  Made a precautionary landing at cape girardeau, engine

running terribly, died on rollout, won't restart.  When I quit

shaking we eventually determined that the left mag had shifted its timing

by nearly 180 degrees.  At the time of the mag check I did not

recognize that the engine would have run fine on the right mag only, I

guess I didn't leave it in that position long enough.  Anyway I sent

both mags to E-mag and this is what happened as I understand it. 

The mag senses the motor position by a magnet soldered to a brass cap or

sleeve that is attached to the drive shaft by a set screw.  Somehow

it loosened up enough that it rotated on the shaft.  This has

happened to a small number of others, they were drafting a letter about

it when I spoke to Brad on Tuesday.  The fix is they are drilling

the shaft and installing a roll pin so it cannot move.  The repair

will be done at no charge.  At this time they were not yet

considering it a mandatory update.



As a side note I can't thank Jarod Callis enough for allowing us to

take his T-18 so that we could make it the last hour on

home.

dalamphere(at)comcast.net
Guest

Posted: Mon Sep 15, 2008 5:01 am Post subject: E-Mag P-Mag Safety info - Referenced msg from Mr. Cotner

Thanks to all those concerned for other builder's safety. That's one of the 

wonderful benefits of subscribing to a group!

Sure am glad none of the pilots were killed as a result of these failures. 

But what a heartache to severely damage a plane that required so much work 

to build! It almost sounds like one ignition failed causing 

kick-backs/pre-detonation/vibration that broke the other side!



I would like to point out that the fix as I understand it that is posted at 

EMag's web-site (and I quote):



"The correction involves 1) replacing the sensor mount with a lighter one 

(now only 4 grams), 2) adding a key way to the shaft and the sensor mount, 

and 3) drilling and roll-pinning the assembly in place."



It was mentioned in one of the posts that drilling a hole through the shaft 

was not acceptable and would create a stress concentration. Please note that 

the end of the shaft is necked down in diameter and has a keyway slot milled 

out - that sounds to me like a major stress concentration area also - but is 

commonly used on magnetos and not a problem to my understanding.



What wasn't said at the EMag site was if they still were using epoxy alone 

to hold the magnet into it's mount. If there's some mechanical shape 

involved that adds to the integrity of it - good.



In the meantime, as I approach finishing of my plane, I'll probably be 

taking the advice of a good friend and go with one conventional magneto and 

one (hopefully) fixed EMag product.



Also, is this an issue with O-360's and not others? (O-320, O-235,O-200)



Dave

tim2542(at)sbcglobal.net
Guest

Posted: Mon Sep 15, 2008 8:14 am Post subject: E-Mag P-Mag Safety info - Referenced msg from Mr. Cotner

Dave, if you read Marc Z's account of his problems carefully, you will note

that he was UNABLE to turn off the EMAG in flight. If he had been able to

turn it off he could have continued on without damaging the engine.

Just so you know, it may not be just a matter of turning off the failed Emag

and flying safely on one mag.

Tim Andres



Dave wrote:

Thanks to all those concerned for other builder's safety. That's one of the 

wonderful benefits of subscribing to a group!

In the meantime, as I approach finishing of my plane, I'll probably be 

taking the advice of a good friend and go with one conventional magneto and 

one (hopefully) fixed EMag product.



Also, is this an issue with O-360's and not others? (O-320, O-235,O-200)



Dave

dalamphere(at)comcast.net
Guest

Posted: Mon Sep 15, 2008 8:58 am Post subject: E-Mag P-Mag Safety info - Referenced msg from Mr. Cotner

I appreciate your concern. .. but ..



I do not believe that the ignition not shutting off is related to the timing 

magnet loosening.

Either the "P" Lead circuit from his ignition switch was broken, the 

ignition switch malfunctioning or miswired, or did not switch to running 

ignition.



Think about it..



I know it's a VERY emotional issue to have someting that you trust fail, but 

let's not give mechanisms sinister minds of their own.. 



Regards,



Dave



---

ftyoder(at)yoderbuilt.com
Guest

Posted: Mon Sep 15, 2008 9:03 am Post subject: E-Mag P-Mag Safety info - Referenced msg from Mr. Cotner

FYI



I installed a Light speed Engineering, Plasma III on my Cont. IO-240 two

years ago and have had NO problems. They have been selling units for over 20

yrs.



I left one mag on just for safety sake and you still get almost all of the

benefits of electronic ignition and save money too.



Great report by Marc and forwarded by Steve.



Thanks, Tim

---

michele.delsol(at)microsi
Guest

Posted: Mon Sep 15, 2008 9:06 am Post subject: E-Mag P-Mag Safety info - Referenced msg from Mr. Cotner

To all,



The issues on PMags are a concern as I have planned for 2 of them on a

TMX-IO360. 



As for shutting down the PMags in flight (it seems that Mark Z had a PMag,

not an Emag), you can't shut it down by just turning the power off because

it will continue generating its own power (above 900 RPM). It does however

have a Plead as regular mags have, which will shut it down by grounding. But

the Plead has to be connected just as on regular mags. Question, did Marc Z

connect his Pleads in such a way that he could shut the PMags down ?



In my set up, I have a regular keyed ignition switch just like regular

magnetos, connecting the Pleads, plus two breaker switches which feed power

to the PMags and LEDS which when lit indicate that the PMags are indeed

getting 12 volts.



Michèle

RV8 - trying to get it finished

-----Message d'origine-----

De : owner-aeroelectric-list-server(at)matronics.com

[mailto:owner-aeroelectric-list-server(at)matronics.com] De la part de Tim

Andres

Envoyé : lundi 15 septembre 2008 18:13

À : aeroelectric-list(at)matronics.com

Objet : RE: E-Mag P-Mag Safety info - Referenced msg from

Mr. Cotner




<tim2542(at)sbcglobal.net>



Dave, if you read Marc Z's account of his problems carefully, you will note

that he was UNABLE to turn off the EMAG in flight. If he had been able to

turn it off he could have continued on without damaging the engine.

Just so you know, it may not be just a matter of turning off the failed Emag

and flying safely on one mag.

Tim Andres



Dave wrote:

Thanks to all those concerned for other builder's safety. That's one of the 

wonderful benefits of subscribing to a group!

In the meantime, as I approach finishing of my plane, I'll probably be 

taking the advice of a good friend and go with one conventional magneto and 

one (hopefully) fixed EMag product.



Also, is this an issue with O-360's and not others? (O-320, O-235,O-200)



Dave

tim2542(at)sbcglobal.net
Guest

Posted: Mon Sep 15, 2008 11:47 am Post subject: E-Mag P-Mag Safety info - Referenced msg from Mr. Cotner

FWIW, a misfiring PMAG/EMAG or plain vanilla mag can break a ring in a

second, and hole a piston in little more time than it takes to read this.

Can you turn it off that quick? Whether it was wired correctly or not is not

the real issue. If it losses time (and it's been well documented that they

do) it can do major damage very quickly. 

Tim Andres



--

jpx(at)Qenesis.com
Guest

Posted: Tue Sep 16, 2008 7:10 am Post subject: E-Mag P-Mag Safety info - Referenced msg from Mr. Cotner

Any possibility that grounding the P-Lead would have no effect if the  

microcontroller was way too busy handling strangely timed interrupts  

due to the timing sensor bouncing around ?  That would depend on  

whether the P-Lead is a standard input read by the microcontroller, or  

goes directly to some circuitry that shuts off the spark outputs.   

Anyone know how the circuirty is designed ?



Jeff Page

Dream Aircraft Tundra #10



 	  Quote: 	
		   As for shutting down the PMags in flight (it seems that Mark Z had a PMag,

 not an Emag), you can't shut it down by just turning the power off because

 it will continue generating its own power (above 900 RPM). It does however

 have a Plead as regular mags have, which will shut it down by grounding. But

 the Plead has to be connected just as on regular mags. Question, did Marc Z

 connect his Pleads in such a way that he could shut the PMags down ?

mlas(at)cox.net
Guest

Posted: Tue Sep 16, 2008 7:37 am Post subject: E-Mag P-Mag Safety info - Referenced msg from Mr. Cotner

Tim,



You bring up the most important issue of unstable timing.  If you time

advances at high power it reduces you detonation margin.  Their are some

important issues here, one you may not recognize detonation, two you

may/will damage internal components of your engine, and three permanent

damage and/or engine can occur.  



I have personally rescued a pilot who landed out on a highway in the

high country of Arizona.  He was very lucky that he found a place to

land and no cars were on the road at the time.  This could have been a

life altering experience.  The recap of the failure mode was attributed

to heat on the emag/pmags.  I'm not sure if that was a correct

assessment.



I have been running the Lightspeed Plasma III in a dual configuration

for over 300 hours.  I have had one hard failure with one ignition unite

at about 60 hours.  Since that repair and upgrade (cooling ports for the

hot AZ summers) both unites have worked perfectly.



I can assure you that if I ever have a problem with maintaining proper

timing that I WILL BECOME A MAGNETO CUSTOMER.  Maintaining proper timing

is the difference between being a glider and an airplane.  An extreme

example of improper timing is shown by watching a Top Fuel dragster or

funny car go off time.  Off timing makes for the BIGGEST explosions in

these cars.  Check out You Tube.



Mike Larkin



31 years flying

30 wrenching

8 years professional wrenching

15 years avionics

5 years professional avionics

21 years professional flying

24 years homebuilding

I'm an airplane guy and safety is no. 1

NO COMPROMISING



--

simon(at)synchronousdesig
Guest

Posted: Tue Sep 16, 2008 8:22 am Post subject: E-Mag P-Mag Safety info - Referenced msg from Mr. Cotner

Jeff, although a good point to bring up, I highly doubt that such an

important function would go to the microprocessor, except as a status input.

Surely it would go to a hard wired shut off circuit outside the micro to

guarantee outside control without software being involved.  If it didn't, it

would be a major design error.  However, all of these details are most

likely proprietary data, and only Emagair would know.



Simon

Do Not Archive

Copyright C 2008



--

Marc Zeitlin

Joined: 16 Sep 2008
Posts: 1
Location: Tehachapi, CA

Posted: Tue Sep 16, 2008 9:22 am Post subject: Re: E-Mag P-Mag Safety info - Referenced msg from Mr. Cotner

I joined the matronics lists to be able to respond to a few of the comments posted here, but don't expect to be a regular.



At any rate:



 	  dalamphere(at)comcast.net wrote: 	
		  Either the "P" Lead circuit from his ignition switch was broken, the ignition switch malfunctioning or miswired, or did not switch to running ignition. 	
The Emagair products I had on my engine (one Pmag and one Emag) were both wired with "P" leads, just as the manual explains, and both ignitions were tested with "mag checks" before every flight, including the one in question.  In fact, you CAN turn off a Pmag, even with the RPM's above the cutoff of the generator kick-in, with a "P-lead" grounding event, and it had always worked before.



The switch worked correctly for 6.5 years prior to and all tests after the failure event, indicating that the switch and wiring were/are working fine. While in the air, I attempted to run off of one EI, then the other EI, then Both EI's, and saw minor differences in operation in the three cases.  After landing and UNPLUGGING the power from the failed EI, the engine ran perfectly on the single remaining EI.



 	  dalamphere(at)comcast.net wrote: 	
		  I do not believe that the ignition not shutting off is related to the timing magnet loosening. 	
I don't know what the firmware in the EI assumes, or how it works, and I don't know what the hardware is doing either.  All I can tell you is that when the EI failed due to the magnet slippage and the HUGE change in timing, in this one case the EI would NOT shut itself off via "P-lead" grounding.  In all other cases of Emagair product failures that I've had (and it's been a substantial number), they've always shut themselves off when grounded, but in this case, it did not.



Believe what you will - I'm certainly more than familiar with believing what I WANT to believe, no matter what the facts of the matter are - just review my usage history with the Emagair products to see that.  But the facts are what the facts are.

_________________
Marc J. Zeitlin
marc_zeitlin@alum.mit.edu
http://www.cozybuilders.org/
http://www.mdzeitlin.com/Marc/

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