ANOTHER P-Mag failure!

tkatc · #1 08-15-2012, 05:35 PM

Flying the other day I was leaning out the mixture and noticed exceptionally high EGTs. So I fed in more gas and she cooled down into the green. Leaned again and again, high EGTs. Tried it a 3rd time and it was normal. This puzzled me. I also felt a surge of power once while taking off. Wasn't real sure about that either. I landed and before departing did a routine mag check. The engine died on the left mag.

Uncowled and looked for obvious problems. None found. Started it up the next day to troubleshoot. This time the routine mag check worked fine but the engine died while checking the left p-mag's "internal" power. I removed the left P-mag and discovered the drive gear was "crunchy" when rotated. I just went through this with the right p-mag about 20 hours ago so I am sure the magnet has once again dislodged and partially disintegrated. We'll see if I have to pay for new circuit boards again! The P-mag is on its way to EMAGair....

guccidude1 · #2 08-15-2012, 05:43 PM

Sorry I may have missed an earlier post, is this a 114 model? Dan

SmilingJack · #3 08-15-2012, 05:45 PM

TK,

How old are they and how many hours?

tkatc · #4 08-15-2012, 06:32 PM

They are 113s. Approx 360 hours. First went into service in 2006. They DID have the SB done regarding the magnet attachment.

SmilingJack · #5 08-15-2012, 06:49 PM

Thanks Tk for the update.

Mine are P114L's. As you know, they only have about 135 hours on them and until I get to the "Vlad" level

I can't comment on how reliable they are.

Knock on Wood, Metal and Composite propellers.....mine have been running well.

Good luck,

Ironflight · #6 08-15-2012, 06:53 PM

Quote:

Originally Posted by tkatc

They are 113s. Approx 360 hours. First went into service in 2006. They DID have the SB done regarding the magnet attachment.

Lots of changes since 2006 if I recall following the development here through the years. I suspect that you will find that with identical vintage equipment, you will have had a very similar failure - engineering works that way.

I have watched the development of most of the EI systems out there, and have hepled rescue friends by flying parts and mags to those with pretty much every system out there - inlcuding Slick mags (and Bendix mags).

I stayed away from the development years of P-Mags myself, but there are now lots and lots of folks flying without failures (with th late-model units).

Paul

RV8R999 · #7 08-15-2012, 07:10 PM

Quote:

Originally Posted by tobinbasford

TK,

My sincere recommendation is to go with Light Speed. With no moving parts, malfunctions are very, very rare. LSE has a long history having been around since the 80s and is very proven. Here is there website: http://www.lightspeedengineering.com/. There are thousands of airplanes flying with LSE. I'm not bashing Emag/PMAG because I've never flown with them, but I can't count how many times I've read about their failures on this forum over the years. Just my .02. I know some folks swear by Emag/PMAG.

different perspective:
Light Speed Plasma III complete failure on take-off in my BD-4... Klaus was a complete "something I'm not allowed to say here" and blamed my installation - even though it worked the two previous hours. Turned out to be a failed mother board. Klaus then explained the significance of infant mortality and acceptable probabilities of electronic components and that failures should be expected...thats great for a 21st century toaster but not ok for an aircraft ignition 2hrs old! Eventually received a total refund but not without a struggle. This was 2006/7

Kyle Boatright · #8 08-15-2012, 07:54 PM

Quote:

Originally Posted by Ironflight

I have watched the development of most of the EI systems out there, and have hepled rescue friends by flying parts and mags to those with pretty much every system out there - inlcuding Slick mags (and Bendix mags).

I think this is a key point. I've seen EI and mag failures over the years, both first and second hand, and have read about plenty of failures in these forums and on the Matronics board. EI failures are often more frustrating than mag failures because their complexity makes them harder to troubleshoot. Also, EI's tend to cost 2x what magnetos do, and people expect equivalent or better reliability for 2x the price.

That said, I suspect a pair of Slicks (or Bendixes) would be more reliable than a system with one or more EI's. Aircraft mag's have been refined for 100+ years. EI's for a fraction of that.

tkatc · #9 08-15-2012, 07:55 PM

Quote:

Originally Posted by Ironflight

Lots of changes since 2006 if I recall following the development here through the years. I suspect that you will find that with identical vintage equipment, you will have had a very similar failure - engineering works that way.

I stayed away from the development years of P-Mags myself, but there are now lots and lots of folks flying without failures (with th late-model units).

Paul

What is considered "late models"? And if these "early models" are so failure prone, why have these 2 p-mags been repaired twice at the factory and sent back into service?

Ironflight · #10 08-15-2012, 08:29 PM

Quote:

Originally Posted by Kyle Boatright

That said, I suspect a pair of Slicks (or Bendixes) would be more reliable than a system with one or more EI's. Aircraft mag's have been refined for 100+ years. EI's for a fraction of that.

That is probably true. But, like everything, unless your ONLY goal is reliability, you have to make trades. EI's have some significant performance advantages over Mags. The question is not if the EI (or mag) of your choice is the MOST reliable ignition available, it is rather if it has reached a sufficient level of reliability to be considered for use.

Paul