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-   -   Dual P-MAG Reliability in 2017 (https://vansairforce.net/community/showthread.php?t=154003)

N941WR 07-24-2018 08:25 AM

Hans, I am sorry to hear about your friend.

That is an interesting report.

I have never spoken with anyone who's P-mags would not self power above ~800 RPM.

This is also one reason why the internal generators should be tested before each flight.

I had one generator fail in flight and did not know it until the next preflight. Even then, the ship's electrical system powered the ignition without even a stumble.

If your P-mags are not self powering above ~800 RPM's, then you need to have a discussion with Emag. They are designed to to provide power when the prop is turning slowly on final.

GalinHdz 07-24-2018 08:34 AM

I am very sorry to hear about your friend. It still hurts but unfortunately, if you are in aviation long enough you will eventually loose a friend.

I don't know all the details of this case but, with any airplane safety of flight system, redundancy is critical. In my case I have the engine driven alternator, the airplane battery and the P-Mag(s) internal generators (triple redundant) for ignition power. I also know, and have on my emergency action checklist, never to go below1,000rpm(s) in flight if I even suspect an electrical failure to the ignition. I check the 1,000rpm number during every engine run-up portion of the pre-flight check. Without a similar installation/procedure then you really need to re-think the basic installation design. No matter what, things will fail so minimize the posibility and consequence(s) of ALL critical equipment failures.

Just my 2 cents.

:cool:

N941WR 07-24-2018 08:46 AM

Hans, I am sorry to hear about your friend.

That is an interesting report.

I have never spoken with anyone who's P-mags would not self power above ~800 RPM.

This is also one reason why the internal generators should be tested before each flight.

I had one generator fail in flight and did not know it until the next preflight. Even then, the ship's electrical system powered the ignition without even a stumble.

If your P-mags are not self powering above ~800 RPM's, then you need to have a discussion with Emag. They are designed to to provide power when the prop is turning slowly on final.

Lufthans 07-24-2018 12:14 PM

Thanks guys. In all fairness, he was not a close friend. Nevertheless, I received RV flying pics from him from all over the place, all the way up to Mali and some other places deep down in Africa. I guess he figured that if he could land an Air France 747 there, he might as well do the same with his RV. Sad that he met his Waterloo in his own back yard...

Anyway, back to the PMAGs. We too check ours before flight. They were wired with just CBs when we purchased the plane, and we've added switches so that we can cut battery power to check for proper operation. Ours cut off somewhere between 800 and 900 rpm.

As for flying - I tend to come in high and fast and use sir Isaac Newton as my main propulsion during final, ideally bleeding my speed off in the last few hundred yards. In my Jodel with a huge constant speed prop this is easy. As in my Fly Baby with tons of exposed rigging wires. More of a challenge in a fixed pitch -4.

I like to believe that I would be ok even if the engine would quit on me on final. Still, good to keep this aspect of the PMAGs in mind, and mention it in a PMAG reliability topic such as this...

Be safe!

Hans

N941WR 07-25-2018 05:22 AM

Hans, next time you fly, do a couple of landings and note your RPM's on final. If you are like me you normally don't look at it but I typically find mine to be around 1,000. Now I was messing with my idle last month and with my lightweight prop had it set so low the engine would stop on final, even with the P-mags firing. My engine is now set to idle right at 600 RPM's when warm.

My style of flying is much like yours. I try to make my landing spot without touching the throttle after I close it on downwind.

jfisher 04-30-2019 09:22 PM

Quote:

Originally Posted by rv6ejguy (Post 1210962)
"Lost Timing" events would certainly worry me.

You can do all the analysis you want but in the end, the system either works properly all the time or it doesn't which means it's either well designed and tested or it isn't.

Nigel's independent testing uncovered several things about the product that people may not have known before. Information is good.

We don't worry about lost timing events or programming changes which don't take hold with SDS because they never happen. Change the timing on CPI and it's instant and accurate to within 1 degree. Shut off the unit or lose power while the engine is turning and it re-initializes and verifies crank position before starting the spark train again when power is restored. Anything else is not acceptable in our view.


...And THIS sums up why I'm ordering the new CPI2 along with a Slick mag for my Thunderbolt 390.

Thanks to everyone for their transparency. I really do get alot of information from a forum like this.

Bavafa 04-30-2019 11:17 PM

Quote:

Originally Posted by rv6ejguy (Post 1210962)
You can do all the analysis you want but in the end, the system either works properly all the time or it doesn't which means it's either well designed and tested or it isn't.

With that, perhaps we should never trust or use a Lycoming engine and render it poor design since there has been a few failures on those engine.

rv6ejguy 05-01-2019 06:21 AM

Quote:

Originally Posted by Bavafa (Post 1343500)
With that, perhaps we should never trust or use a Lycoming engine and render it poor design since there has been a few failures on those engine.

How do you stretch my comment to Lycoming engines? We're talking EIs here. Anything can fail, mechanical or electronic. My comment was about specific design aspects on one EI which affected operation for years.

In my occupation, I get to hear all the bad stuff/ failures about not only our products, but also competitor's products from people using them in the field.

Do you believe "lost timing" and starting kickback events are acceptable on EI systems?

Brantel 05-01-2019 06:26 AM

Quote:

Originally Posted by rv6ejguy (Post 1343522)
Do you believe "lost timing" and starting kickback events are acceptable on EI systems?

Ross,

I am interested in your products for my RV10 and will be considering them when I get to that point but both of these issues have been resolved for some time with the P-Mags. Many of these reports of failures leave out critical information and in many cases turn out to be installation issues or failure to update to the latest hardware/firmware or just plain old operator error.

My biggest beef with the P-Mag is the aggressive advance curve. As I reported six years ago, it is too aggressive. http://www.vansairforce.com/communit...ighlight=curve

I use the limited programmability of the P-Mag to keep the advance under control.

rdrcrmatt 05-01-2019 07:43 AM

Quote:

Originally Posted by Brantel (Post 1343523)
Ross,

I am interested in your products for my RV10 and will be considering them when I get to that point but both of these issues have been resolved for some time with the P-Mags. Many of these reports of failures leave out critical information and in many cases turn out to be installation issues or failure to update to the latest hardware/firmware or just plain old operator error.

My biggest beef with the P-Mag is the aggressive advance curve. As I reported six years ago, it is too aggressive. http://www.vansairforce.com/communit...ighlight=curve

I use the limited programmability of the P-Mag to keep the advance under control.

Except that the 6-cyl PMag is still pretty much vaporware.

Brantel 05-01-2019 08:51 AM

Quote:

Originally Posted by rdrcrmatt (Post 1343540)
Except that the 6-cyl PMag is still pretty much vaporware.

My RV7 has dual Pmags. I am not holding my breath on the 6cyd. model.

Bavafa 05-01-2019 08:52 AM

Quote:

Originally Posted by rv6ejguy (Post 1343522)
How do you stretch my comment to Lycoming engines? We're talking EIs here. Anything can fail, mechanical or electronic. My comment was about specific design aspects on one EI which affected operation for years.

In my occupation, I get to hear all the bad stuff/ failures about not only our products, but also competitor's products from people using them in the field.

Do you believe "lost timing" and starting kickback events are acceptable on EI systems?

Ross,
I believe Brantel covered it really well.
Such comment from a well knowledgeable person such as yourself on the subject matter will sound like he is trying to misrepresent the situation especially if he is a competitor

PMAG has had its fair share of issues and no one will know if there are still some undiscovered issues, much like any other product. But their simplicity in installation and the self-powering makes it a tough competition for any EI. But that is not to say that this is the product for everyone.

sailvi767 05-01-2019 09:02 AM

I am sorry for the loss of your friend. Reading the report however suggests this was not a PMag issue. The mechanic who did the install had never done one before. He incorrectly wired the Pmags to a common power source and after installation all RPM indications were lost. In addition it appears extensive work was done on the alternator and that it was inop for the flight and flights before. He was flying on battery only with no RPM indications on PMags. Not a good combination especially when known before flying.
G

rv6ejguy 05-01-2019 06:51 PM

Quote:

Originally Posted by Bavafa (Post 1343559)
Ross,
I believe Brantel covered it really well.
Such comment from a well knowledgeable person such as yourself on the subject matter will sound like he is trying to misrepresent the situation especially if he is a competitor

PMAG has had its fair share of issues and no one will know if there are still some undiscovered issues, much like any other product. But their simplicity in installation and the self-powering makes it a tough competition for any EI. But that is not to say that this is the product for everyone.

I didn't dredge up this 2017 thread and nobody disputes that Pmags are about the easiest EI to install on Lycomings and that lots of folks like them. They are probably currently the top selling EI for 4 cyl. Experimental Lycomings on the planet. I'd also say that things change in 2 years. What might have been valid in 2017 may no longer be...

There are numerous choices of EIs these days and people can buy whichever one they like.


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