Today's Message Index:
----------------------
1. 11:21 AM - Re: Toggle Switches with Fast-On TabsToggle Switches with Fast-On TabsToggle Switches with Fast-On Tabs (Joe)
2. 01:59 PM - Re: Toggle Switches with Fast-On TabsToggle Switches with Fast-On TabsToggle Switches with Fast-On Tabs (Vernon Little)
3. 04:00 PM - Re: Toggle Switches with Fast-On TabsToggle Switches with Fast-On TabsToggle Switches with Fast-On Tabs (B Tomm)
4. 04:10 PM - P-Mag and E-Mag safety info from canard-aviators list... (Steve Stearns)
5. 04:12 PM - Part 2 forwarded P-Mag E-Mag Safety info... (Steve Stearns)
6. 04:13 PM - Part 3 P-Mag E-Mag Safety info.... (Steve Stearns)
7. 04:14 PM - Part 4 P-Mag E-Mag Safety info.... (Steve Stearns)
8. 04:21 PM - E-Mag P-Mag Safety info - Referenced msg from Mr. Cotner (Steve Stearns)
Message 1
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Subject: | Re: Toggle Switches with Fast-On TabsToggle Switches |
with Fast-On TabsToggle Switches with Fast-On Tabs
Vern,
That was a good idea to measure the voltage across the switch. By
measuring from terminal to terminal, do you mean between the switch
terminals and not between the fast-on connectors? Is it possible to
measure voltage between the rivet and switch terminal? Just curious.
Do you live in a high humidity environment? Whether you do or not,
the switches are probably failing because of corrosion. Microswitch
makes a military grade sealed switch, the TW Series. It might be
expensive but could save you aggravation and failure at critical times.
But you have already purchased new switches, maybe next time. Here is
another suggestion for next time: buy double-pole switches and connect
the two halves in parallel. If one side of the switch fails, the other
side will keep you flying. Any heat developed in a double-pole switch
will be dissipated over a larger area and thus reduce the temperature
rise and slow down the corrosion process.
Checking voltage drop across switches could be added to the list of
things to do at the annual condition inspection. Many planes could be
flying with switches that get warm. The pilot is unaware until there is
smoke or until something quits working.
Joe
Message 2
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Subject: | Toggle Switches with Fast-On TabsToggle Switches |
with Fast-On TabsToggle Switches with Fast-On Tabs
Hi Joe.
I measured between switch terminals, but wasn't able to measure the
voltage
between the terminal and rivet.
My aircraft is about 10 miles from the west coast, but there are no
signs of
corrosion anywhere. Not only is it hangared, but I keep a
heater/blower in
the cockpit at all times when not flying.
I've considered the double-pole idea, but the wiring is a bit of a pain,
and
without understanding the root cause, I'm not sure I'd go to the effort.
Although I had no smoke in the cockpit, my panel was warm. Then, I did
the
finger test on the switches to see what was up. I think the finger test
is
just as good as a voltage drop test if access is limited.
I hope that a lot of you are out there now poking at switches to see if
they
have the same symptoms!
Vern
-----Original Message-----
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Joe
Sent: September 14, 2008 11:20 AM
Subject: Re: AeroElectric-List: Toggle Switches with Fast-On TabsToggle
Switches with Fast-On TabsToggle Switches with Fast-On Tabs
Vern,
That was a good idea to measure the voltage across the switch. By
measuring
from terminal to terminal, do you mean between the switch terminals and
not
between the fast-on connectors? Is it possible to measure voltage
between
the rivet and switch terminal? Just curious.
Do you live in a high humidity environment? Whether you do or not,
the
switches are probably failing because of corrosion. Microswitch makes a
military grade sealed switch, the TW Series. It might be expensive but
could save you aggravation and failure at critical times. But you have
already purchased new switches, maybe next time. Here is another
suggestion
for next time: buy double-pole switches and connect the two halves in
parallel. If one side of the switch fails, the other side will keep you
flying. Any heat developed in a double-pole switch will be dissipated
over
a larger area and thus reduce the temperature rise and slow down the
corrosion process.
Checking voltage drop across switches could be added to the list of
things to do at the annual condition inspection. Many planes could be
flying with switches that get warm. The pilot is unaware until there is
smoke or until something quits working.
Joe
Message 3
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Subject: | Toggle Switches with Fast-On TabsToggle Switches |
with Fast-On TabsToggle Switches with Fast-On Tabs
Vern,
My RV is no where close to flying yet but I have already purchased Carling
toggle switches too. So I will be watching this thread closely and thank
you for posting here. I hope that you positively find the root cause and
all can benefit.
I'm sure Bob will chime in on this but I'm not sure about the theory of
using a double pole switch to "spread" the load. A double pole switch may
delay the symptom, but it could still occur eventually and possibly very
soon after the first set of contacts fail. I guess it depends on what the
actual cause of the failure is. Poor crimps, over current heat damage,
corrosion, determination due to contact arcing etc.
To truly have a secondary (backup) switch, I would think that it would need
to be a separate switch that is not used until the primary one fails and is
turned off. My opinions only. Your mileage may vary. I hope this failure
is positively identified.
Bevan
_____
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Vernon
Little
Sent: Sunday, September 14, 2008 1:55 PM
Subject: RE: AeroElectric-List: Toggle Switches with Fast-On TabsToggle
Switches with Fast-On TabsToggle Switches with Fast-On Tabs
Hi Joe.
I measured between switch terminals, but wasn't able to measure the voltage
between the terminal and rivet.
My aircraft is about 10 miles from the west coast, but there are no signs of
corrosion anywhere. Not only is it hangared, but I keep a heater/blower in
the cockpit at all times when not flying.
I've considered the double-pole idea, but the wiring is a bit of a pain, and
without understanding the root cause, I'm not sure I'd go to the effort.
Although I had no smoke in the cockpit, my panel was warm. Then, I did the
finger test on the switches to see what was up. I think the finger test is
just as good as a voltage drop test if access is limited.
I hope that a lot of you are out there now poking at switches to see if they
have the same symptoms!
Vern
-----Original Message-----
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Joe
Sent: September 14, 2008 11:20 AM
Subject: Re: AeroElectric-List: Toggle Switches with Fast-On TabsToggle
Switches with Fast-On TabsToggle Switches with Fast-On Tabs
Vern,
That was a good idea to measure the voltage across the switch. By measuring
from terminal to terminal, do you mean between the switch terminals and not
between the fast-on connectors? Is it possible to measure voltage between
the rivet and switch terminal? Just curious.
Do you live in a high humidity environment? Whether you do or not, the
switches are probably failing because of corrosion. Microswitch makes a
military grade sealed switch, the TW Series. It might be expensive but
could save you aggravation and failure at critical times. But you have
already purchased new switches, maybe next time. Here is another suggestion
for next time: buy double-pole switches and connect the two halves in
parallel. If one side of the switch fails, the other side will keep you
flying. Any heat developed in a double-pole switch will be dissipated over
a larger area and thus reduce the temperature rise and slow down the
corrosion process.
Checking voltage drop across switches could be added to the list of
things to do at the annual condition inspection. Many planes could be
flying with switches that get warm. The pilot is unaware until there is
smoke or until something quits working.
Joe
href="http://www.matronics.com/Navigator?AeroElectric-List">http://www.matro
nics.com/Navigator?AeroElectric-List
href="http://forums.matronics.com">http://forums.matronics.com
href="http://www.matronics.com/contribution">http://www.matronics.com/c
Message 4
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Subject: | P-Mag and E-Mag safety info from canard-aviators list... |
What follows is some critical safety information published by others
with a request to please distribute. From my experiences on the
canard-aviators listed I believe Marc Z. to be a particularly credible
source. My exposure to the other two authors is too limited to have an
informed opinion.
Steve Stearns
Boulder/Longmont, Colorado
CSA,EAA,IAC,AOPA,PE,ARRL,BARC (but ignorant none-the-less)
Restoring (since 1/07): N45FC O235 Longeze Cothern/Friling CF1 (~1000 Hrs)
Flying (since 9/86): N43732 A65 Taylorcraft BC12D
********** Messages from the Canard-aviators list follow ************
5.
Emagair Emag/Pmag Electronic Ignition warning - Part 1
Posted by: "Marc J. Zeitlin" marc_zeitlin@alum.mit.edu zeitlinm
Sun Sep 14, 2008 5:14 am (PDT)
Folks:
While I had planned on writing a description and warning of the issues
that I had on my trip east in July/August with my electronic ignitions
from Emagair (Pmag/Emag), the message that was forwarded to the
canard-aviators list by Ric Lee, With a write-up by Gary Cotner
describing his crash of his Thorp T-18 due to Emag/Pmag failures has
prompted me to accelerate the writing of this warning. So here it is.
History (short - a search of the COZY mailing list archives will turn
up all my previous posts on this subject):
In August of 2004 I purchased a Pmag from Emagair to replace one of my
magnetos. During operation over the next months, I had numerous
issues with intermittent missing. Brad and Tom at Emagair were
extremely good at customer service and replaced my units numerous
times whenever I had an issue. Obviously, I was not happy about the
problems, but I truly wanted them to succeed - the idea for the units
is a great one. By the summer of 2005, after having problems with a
unit during my Instrument Instruction, and further problems with
replacement units, I threw in the towel, sent the unit back, and got a
refund. While replacing the unit with a rebuilt magneto with Ken
Miller, we discovered some anomalous wear on the Emagair soft drive
gear - Ken was very concerned about this, and I'll get to that issue
later.
Fast forward to February, 2007. I figured they had had more than
enough time (1.5 years) to fix any issues that they had, so I wanted
to give Emagair another try. I know that many of you thought that I
was insane, and given the rest of this story, you may have very well
been correct. But I wanted them to succeed and put Slick/Bendix out
of business... At any rate, I got a new generation 3 unit (version
113) and installed it. Within the first month, I had issues with
mis-timing, and worked with Emagair to replace the unit. After
problems with a second unit, I had been able to run for over a year
and 120 hours with no issues whatsoever on the third version 113 unit
that I had installed in the spring of 2007. I finally felt like they
had the issues licked.
After having a magneto failure (reported on list) back in early June
of this year (2008), I decided that since I had been having good luck
with the Pmag, that I'd get an Emag to go along with it to replace the
magneto that had failed. Emagair offered to upgrade my existing Pmag
from the version 113 that I had to a version 114 at the same time that
they were sending me a new version 114 Emag. Hey - something for
nothing - take it, right?
I installed both units and flew locally for about 10 hours, taking
friends for rides, going places for lunch, etc. No problems at all -
engine was running like a top.
To Be Continued....
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Subject: | Part 2 forwarded P-Mag E-Mag Safety info... |
************** From Canard Aviators ****************
--
Marc J. Zeitlin mailto:marc_zeitlin@alum.mit.edu
http://www.cozybuilders.org/
Copyright (c) 2008 http://www.mdzeitlin.com/Marc/
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6.
Emagair Emag/Pmag Electronic Ignition warning - Part 2
Posted by: "Marc J. Zeitlin" marc_zeitlin@alum.mit.edu zeitlinm
Sun Sep 14, 2008 5:14 am (PDT)
Continued from Part 1:
In mid July, 2008, I headed east at the crack of dawn for a two week
trip that would take me to Provincetown, MA for a week vacation, a few
days in NJ with my mother and sisters for my father's footstone
dedication, and then to OSHKOSH with my wife for the obvious reasons
and to give the COZY and Canard fora. I took off at 5:30 AM, just as
the sun was rising, and headed east. After about an hour and a half,
near Kingman, AZ, the engine started running a TINY bit differently -
a mag check seemed clean - it was running OK on either EI, but the
CHT's had gone up about 10-20 degrees and the power was down a bit. I
continued the flight for another 4.5 hours with no issues, landing in
Clinton, OK for gas, oil and a bathroom break.
Upon runup, I found that one EI was NOT working at all, but I was in
the middle of nowhere and had places to be. I'll be writing another
story about all of the poor decisions I made on this 36.5 hour trip,
and won't address them here, but I'll just describe the events because
that's what's germane to the warning.
I decided to take off on one EI to get to Ohio, where I'd be staying
overnight with Bill Kastenholz. I took off on one EI, climbed over
the airport to cruising level, and headed off. About 10 minutes after
takeoff, the second EI kicked in and the engine continued running as
it had for the previous 4.5 hours - CHT's a little elevated (but not
dangerous), power a bit down from normal. 5.5 hours later I landed in
Ohio.
The next morning, after refueling, I took off (again on one EI - the
bad one seemed to not work when cold and work when hot) and flew
towards MA. On the way I stopped at Westerly, RI to visit Don
Ponciroli but we didn't connect and I called Emagair to talk to them
about the issues I was having with the 114 units. I then flew to
Norwood, MA to visit Jose Velez, and after a couple of hours on to
Provincetown, MA. Each time, I took off on one EI, and each time, the
second one kicked in after 10 minutes of warming up. It was apparent
that there was a problem with timing, but since it didn't run on the
ground when cold, I couldn't adjust it.
Emagair sent me a replacement unit in P'town and I replaced it. A
test runup indicated that it was running fine, along with the other
one. On Friday of that week, I flew down to Brookhaven airport on
Long-Island with my son and nephew to bring my nephew home after the
vacation week. There was no issue on that flight, and no issue on
runup. However, about 7 minutes after taking off from Brookhaven,
just about over Orient Point, the engine suddenly started running like
crap - RPM's dropped off, CHT's shot through the roof on two
cylinders, and power decreased substantially. I brought the power
back and made a precautionary landing with my son at Easthaven.
On the ground, I called Ken Miller (whom I had spoken to for a few
minutes on the ground at Brookhaven), described the symptoms, and he
gave me a few things to look for. It turned out that one of the EI's
had failed catastrophically, with the timing shifting by a huge amount
(no wonder the CHT's were through the roof - it was firing on the
intake stroke). Retiming it twice did nothing - it wouldn't hold a
timing set. The one that had failed was NOT the replacement unit - it
was the second unit that had worked OK on the whole flight east. The
replacement unit was working OK. I had to completely unplug the power
from the unit in order to get it to stop firing, but once I did, the
engine ran OK on the one EI (the replacement unit) that was left.
My son and I took off from Easthaven on the one EI and flew
uneventfully back to Provincetown. I called Emagair to let them know,
and they agreed to send another replacement to NJ, where I would be
the next day. I sent my wife to NJ via car instead of having her fly
with me, and we made arrangements for her to fly commercial to OSH
rather than with me in the plane - I would pick her up when I got
there in Appleton.
To Be Continued...
--
Marc J. Zeitlin mailto:marc_zeitlin@alum.mit.edu
http://www.cozybuilders.org/
Copyright (c) 2008 http://www.mdzeitlin.com/Marc/
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Message 6
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Subject: | Part 3 P-Mag E-Mag Safety info.... |
*************** Message forwarded from Canard Aviators list follows
************************
7.
Emagair Emag/Pmag Electronic Ignition warning - Part 3
Posted by: "Marc J. Zeitlin" marc_zeitlin@alum.mit.edu zeitlinm
Sun Sep 14, 2008 5:15 am (PDT)
Continued from Part 2:
In NJ, I received another replacement unit, went out to Caldwell
airport and installed it. Checks of both EI's indicated that they
were working.
The next day I took off and headed to OSH. About 1.5 hours out, over
Pennsylvania, one of the EI's started acting up with the same symptoms
as the first bad EI - slightly elevated CHT's, timing off a bit,
slightly lower power. I navigated from airport to airport, staying as
high as was necessary for glide distance, and made it to OSH in 6.5
hours - about 5 after the EI failure. At OSH, I removed the bad EI
and took it, along with the other two failed units, to the Emagair
booth at OSH. We disassembled the units and found that all three had
had catastrophic mechanical failures inside that caused them to not be
able to hold timing to any extent at all.
Emagair stated that they had not had any failures other than mine of
this type, but agreed that this was a design failure. They attributed
the failure to excessive vibration caused in some way by my engine,
and this plays back to the wear on the removed EI drive gears that Ken
Miller and I had seen two years previously. Emagair believed that
there was some strange thing going on in my engine that was causing
excessive vibration, which beat up the gears and which caused the
catastrophic failure of the sensor magnet holder that I had occur
three times.
I told them that I just needed to fly 11.5 hours more to get home to
Tehachapi, and that the plane would be grounded (which it is) for an
engine teardown. They did a temporary repair on two of the EI's,
which, along with the one in the plane that was still working, gave me
three to use for the 11.5 hour flight(s). When I left OSH a couple of
days later, I determined that I would also change my flight
characteristics to see if I could lessen the stress on the EI's - I
never let the RPM's exceed 2500, either in climb or cruise, and I
climbed at 140 mph to ensure excessive cooling to the EI. Since the
examination of the failed units had pointed to heat and vibration as
being the cause of the failures (mechanical - NOT electrical), I
wanted to change the heat and vibration signatures of my flying.
I was able to fly from OSH to TSP, with one stop in Tucumcari, NM,
without any further failures. The plane is grounded and is coming
apart; the EI's have been removed and returned, and I've got my refund.
Next, I'll describe the issues, the warning, and my recommendations.
To Be Continued:
--
Marc J. Zeitlin mailto:marc_zeitlin@alum.mit.edu
http://www.cozybuilders.org/
Copyright (c) 2008 http://www.mdzeitlin.com/Marc/
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Message 7
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Subject: | Part 4 P-Mag E-Mag Safety info.... |
************ Following message forwarded from Canard Aviators List
*******************
8.
Emagair Emag/Pmag Electronic Ignition warning - Part 4
Posted by: "Marc J. Zeitlin" marc_zeitlin@alum.mit.edu zeitlinm
Sun Sep 14, 2008 5:16 am (PDT)
Continued from Part 3:
So what's happening here? As Mr. Cottner and Mr. Read have stated,
the Pmag/Emag units lose timing information, firing at arbitrary and
sometimes random times. Clearly, this screws up the workings of the
engine, sometimes to the point of having no power whatsoever. Mr.
Cottner had four failures and lost his airplane because of this
failure mode - Mr. Read had to make a precautionary landing, and I had
three failures and one precautionary landing.
Emagair has issued a SB on both the 113 and 114 units. If you recall,
I had timing issues with my 113 units as well. They have instituted a
"fix" for the issue, notwithstanding that the 114 mechanical redesign
was in part already a "fix" for the problems with the 113 versions.
The Emagair units use a small magnet and a hall effect sensor to
determine crankshaft position. It's an ingenious solution, because it
uses a sensor that can determine crank position within 1 degree, not
just when at TDC or within 10 - 30 degrees, as some other EI's do.
However, the mounting of the sensor magnet has been flawed from
version 113 onward. In version 113, the magnet was epoxied into a
metal cup at the end of a shaft. The other end of the shaft had the
magneto gear on it and was in intimate contact with the accessory case
gears inside the engine, along with the engine oil. This guaranteed
that the shaft would get just about as hot as the oil in the accessory
case - about 200 F, if not more.
Due to the very thin bond line of the epoxy holding the magnet in the
cup and the differential CTE's (coefficients of thermal expansion) of
the magnet and cup, the thermal stresses in the epoxy can be very
large, cracking the epoxy. This would allow the magnet to rotate,
thereby losing positional accuracy and timing.
After having this failure mode pointed out to them (by me) a year and
a half ago, and after having refused my offers to assist them in
redesigning the mechanical portion of the units gratis (I am a
mechanical engineer with 27 years of experience), Emagair, with an EE
but no ME on staff, redesigned the magnet holding portion of the units
for the version 114's. They soldered the magnet into a large brass
holder, and then glued the holder onto the same shaft that the cup had
previously been attached to. They then added two locktited set screws
to the holder which applied force to the shaft. There was no flat on
the shaft where the set screws touched it.
This "fix" was far worse than the disease it was attempting to solve,
and is the root cause of the horrible performance of the version 114's
under heat and vibration loading. Now that the mass of the brass
holder has been made much larger than the mass of the magnet alone,
the stresses in the glued bond-line are far higher than previously,
and under heat and vibration is guaranteed to fail eventually. The
set screws do absolutely nothing, since the CTE of brass is much
higher than the CTE of the steel shaft, so as the system gets hot, the
set screws don't even touch the shaft. Failure of the glue bond line
is sufficient to cause the holder to be able to rotate, with the same
mis-timing issues as with a magnet disbond in the version 113 units.
Although Emagair has issued an SB, describing a "fix", I do not have
ANY confidence in this "fix"'s actually working in the long term. As
with Mr. Cotner's warning, I don't believe that the keyway and
roll-pin are anything resembling an adequate solution to the magnet
mounting problem, which is obviously NOT specific to my engine and/or
installation. As more hours are put on these units (I fly 120
hours/year - more than twice the homebuilt average), more will fail,
and I have no confidence that this fix will substantially change this
situation.
Recommendations:
My recommendations, based on my opinions and my examination of MANY
Emagair unit disassemblies are these:
1) If you are flying with a version 113 or 114 product from Emagair,
ground your plane immediately and remove the units. Do NOT fly with
them, or with the "fix" described in the SB. It will work for a
while, but for how long?
2) If you have a unit that you have purchased but haven't used yet,
return it for a refund - do NOT put it on your aircraft and fly it.
3) If you were considering Emagair products for your engine, consider
something else - do NOT purchase one and put in on your aircraft.
When Emagair have hired a competent mechanical engineering firm to
redesign their systems, have FULLY tested the units under O-360 type
vibration loads for thousands of hours, and publicly published the
results, THEN in may be appropriate to consider these units. Until
then, it is not.
If Mr. Cotner, Mr. Read, and my experiences with these units put
Emagair out of business, and it costs some of you the opportunity to
get a refund on your units, I'm sorry for that, but Mr. Cotner was
lucky, and relying on luck to keep people alive is not acceptable.
Everything that I have written here is either my personal experience,
my opinion, or my recommendation based on my opinion.
I know that many of you are saying (to yourselves or to others) "I
told you so", and you're right - you told me so, but my desire for
Emagair to succeed overrode what should have been enough evidence to
the contrary. Feel free to write me with "I told you so" messages, if
it makes you feel better.
I'm happy to address any issues, comments, or questions that anyone
may have. Since Emagair never responded to my entreaties to sign an
non-disclosure agreement with them, I do not have any responsibility
not to explain the inner workings of the units or the problems therein.
PLEASE, PLEASE, PLEASE - distribute these messages (and Mr. Cotner's
and Mr. Read's) to any and all aviation related mailing lists, fora,
and printed newsletters.
--
Marc J. Zeitlin mailto:marc_zeitlin@alum.mit.edu
http://www.cozybuilders.org/
Copyright (c) 2008 http://www.mdzeitlin.com/Marc/
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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.
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