Emergency Landing Aftermath

Lance F

Lance F

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Lance F
The field repair made to get me out of Virginia after my in-flight engine stoppage was the replacement of both sets of contacts in my dual Bendix mag. Since the contact gap had been checked during annual only a couple of weeks previously, I was concerned as to the cause of the rapid wear (contact point gap from .016" to 0" on BOTH sets in less than 5 hours!). So we checked mag capacitors (within spec but replaced anyway), continuity of P-leads to ground (OK), and reset timing. Yesterday, did a series of runups on the ramps and everything checked out. We put the cowlings back on, taxied out to the hold short line, did a run up and the plug on #4 left mag wasn't firing (I love my engine analyzer). Pulled cowling, checked plug (top of cylinder) and it was not fouled.

Very frustrating. Could be something deeper in the mag; could be the wiring harness; could even be the plug. But I'm getting very tired of the time and expense of swapping parts. Plus I need 100% confidence in this engine to fly IMC, night, long xcountries, over mountainous areas and water (not necessarily all at the same time, though).

So this situation plus various aggravating oil leaks have driven me to consider having this whole engine rebuilt with less than 1500 hours SMOH even though it is strong and has high compressions.

Advice on such a rebuild are welcome.
 
Lance, good to hear from you. Glad you are making the decision you want to make.

(I've gotten through about 1/2 of your interview on the Pilotcast)

Also--what model engine analyzer do you have? Some of the JPI's are really good! :yes:

Gee, really oddball problems you've been havin' with the plane. I hope all gets well real soon and keep posting! This is valuable knowledge to the rest of us :cheerswine:

Jason
http://pilotcast.com
 
HPNPilot1200 said:
Also--what model engine analyzer do you have? Some of the JPI's are really good! :yes:
Jason
Click to expand...
I have an EDM 800 which give me fuel flow and fuel totalizer (very accurate) as well as all the engine info.

For whatever reason when I downloaded the analyzer after my engine stoppage, I got a message that the file is bad, so I can't see the data from this event :( .
 
Lance F said:
I have an EDM 800 which give me fuel flow and fuel totalizer (very accurate) as well as all the engine info.

For whatever reason when I downloaded the analyzer after my engine stoppage, I got a message that the file is bad, so I can't see the data from this event :( .
Click to expand...

Arggg, that stinks.. My grandfathers has a JPI EDM800 as well and it really saved him when he experienced Pre-ignition in #5 and later prompted him to swap engines for a rebuilt.

http://www.avweb.com/news/columns/184108-1.html
 
Lance F said:
The field repair made to get me out of Virginia after my in-flight engine stoppage was the replacement of both sets of contacts in my dual Bendix mag. Since the contact gap had been checked during annual only a couple of weeks previously, I was concerned as to the cause of the rapid wear (contact point gap from .016" to 0" on BOTH sets in less than 5 hours!). So we checked mag capacitors (within spec but replaced anyway), continuity of P-leads to ground (OK), and reset timing. Yesterday, did a series of runups on the ramps and everything checked out. We put the cowlings back on, taxied out to the hold short line, did a run up and the plug on #4 left mag wasn't firing (I love my engine analyzer). Pulled cowling, checked plug (top of cylinder) and it was not fouled.

Very frustrating. Could be something deeper in the mag; could be the wiring harness; could even be the plug. But I'm getting very tired of the time and expense of swapping parts. Plus I need 100% confidence in this engine to fly IMC, night, long xcountries, over mountainous areas and water (not necessarily all at the same time, though).

So this situation plus various aggravating oil leaks have driven me to consider having this whole engine rebuilt with less than 1500 hours SMOH even though it is strong and has high compressions.

Advice on such a rebuild are welcome.
Click to expand...

I have nothing useful to contribute - but I have to say that you made me smile trying to imagine flying over mountains and water simultaneously.
 
I wouldn't replace the whole engine if all you need is a new ignition system, Lance!
 
Let'sgoflying! said:
I wouldn't replace the whole engine if all you need is a new ignition system, Lance!
Click to expand...

Roger...how many hours on the mags....for some reason 500 hours between overhauld or replacement sticks in my head.

Len
 
Are you confident in the guys doing the work? Confident in the parts. Unfortunately, they can make a substantial difference. On the Bonanza Board, one benefit is a frank discussion of each of these.

I had two Prestolite Alternators retire early. Went to another rebuilder and have not had another issue. The Bendix Mags on my plane through a much stronger spark if you measure it than the competitor's mags.

Even if you rebuild the engine, what parts will you use for the ignition?

BTW, on more than one occassion, a new plug has failed when I've done a LOP mag. check--brand new, out of the box.

Best,

Dave
 
Lance F said:
The field repair made to get me out of Virginia after my in-flight engine stoppage was the replacement of both sets of contacts in my dual Bendix mag. Since the contact gap had been checked during annual only a couple of weeks previously, I was concerned as to the cause of the rapid wear (contact point gap from .016" to 0" on BOTH sets in less than 5 hours!). So we checked mag capacitors (within spec but replaced anyway), continuity of P-leads to ground (OK), and reset timing. Yesterday, did a series of runups on the ramps and everything checked out. We put the cowlings back on, taxied out to the hold short line, did a run up and the plug on #4 left mag wasn't firing (I love my engine analyzer). Pulled cowling, checked plug (top of cylinder) and it was not fouled.

Very frustrating. Could be something deeper in the mag; could be the wiring harness; could even be the plug. But I'm getting very tired of the time and expense of swapping parts. Plus I need 100% confidence in this engine to fly IMC, night, long xcountries, over mountainous areas and water (not necessarily all at the same time, though).

So this situation plus various aggravating oil leaks have driven me to consider having this whole engine rebuilt with less than 1500 hours SMOH even though it is strong and has high compressions.

Advice on such a rebuild are welcome.
Click to expand...

I'd keep running the engine for a while yet if i were you. oil leaks and ignition problems just aren't something worth rebuilding an engine for IMO.

WRT the ignition problem, have you checked the internal magneto timing?
 
The dual Bendix mag (D3000) was rebuilt 350 hours ago. I guess changing the plug and trying it is worth a shot, but the fact that it worked fine on a 2.75 hour flight, worked fine on a mag check after carefully checking point gap, replacing capacitors, and dialing in engine timing...and then didn't fire 5 minutes later doesn't make sense. Likely culprit is the wiring harness, since it doesn't "look" so good.

I'm not sure about checking the mag internal timing. My mechanic bought the full Bendix service manual ($150) just to support me, and it's a pretty impressive book. Is the internal timing something you just check or does it involve further disassembly of the unit?

Maybe looking at a rebuild is a bit over reaction. Thanks for the comments. Does anybody know if I get a new ignition wire set for this dual mag, does that include a new cap with the wires already installed in it?
 
Lance F said:
I'm not sure about checking the mag internal timing. My mechanic bought the full Bendix service manual ($150) just to support me, and it's a pretty impressive book. Is the internal timing something you just check or does it involve further disassembly of the unit?
Click to expand...

I believe it can be checked without disassembly, but I don't know about making the adjustment. Internal timing is about the relationship between the camshaft angle the the points open and where the magnet passes the coil's pole gap. If it's wrong, the spark will be weaker than it's supposed to be and then it doesn't take much for a plug to fail.
 
If the wires looked old, anytime you mess with them (as was probably done when they worked on the mag) you can 'push them over the edge'.

I once helped a pal with his spark plugs. I mentioned the wires were frayed & nasty, needed replacing. Sure enough, even gentle handling of the wires managed to break the insulation and one was shorting out on first run-up. It looked much nicer with those nice new wires too!
I bet you can get a complete harness with mag cap, I have not heard of anyone making up their own anymore.

lancefisher said:
I believe it can be checked without disassembly, but I don't know about making the adjustment. Internal timing is about the relationship between the camshaft angle the the points open and where the magnet passes the coil's pole gap. If it's wrong, the spark will be weaker than it's supposed to be and then it doesn't take much for a plug to fail.
Click to expand...

Here is a file that tells all about timing the D3000

Well it wont take it, its an exe file.
You can dl and view it here
http://www.sacskyranch.com/timingbendixslick.htm
 
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Dave Siciliano said:
Are you confident in the guys doing the work? Confident in the parts. Unfortunately, they can make a substantial difference. On the Bonanza Board, one benefit is a frank discussion of each of these.
Dave
Click to expand...
The mag was rebuilt in late 2002 about 350 flight hours ago by Executive Accessories in Ft. Lauderdale before I bought this plane. The parts we've put in (contacts and capacitors) are PMA Bendix parts out of sealed bags.

The more I think about it the more I lean towards the wiring harness, at least for some of the issues. The problem is, I thought I had the root cause figured out before...and I was wrong:dunno: .
 
Happens to all of us. We all know all mechanics and all parts aren't created equal. Life would sure be easier as plane owners if we knew who these folks were to begin with!!

Dave
 
NickDBrennan said:
I have nothing useful to contribute - but I have to say that you made me smile trying to imagine flying over mountains and water simultaneously.
Click to expand...

It's possible

"The Mid-Ocean Ridge is Earth's longest mountain range. The ridge circles the globe from the Arctic Ocean to the Atlantic Ocean passing into the Indian Ocean and crossing into the Pacific Ocean. This range is four times longer than the Andes, Rocky and Himalaya Mountains combined."

:D :D :D
 
Lance F said:
The field repair made to get me out of Virginia after my in-flight engine stoppage was the replacement of both sets of contacts in my dual Bendix mag. Since the contact gap had been checked during annual only a couple of weeks previously, I was concerned as to the cause of the rapid wear (contact point gap from .016" to 0" on BOTH sets in less than 5 hours!). So we checked mag capacitors (within spec but replaced anyway), continuity of P-leads to ground (OK), and reset timing. Yesterday, did a series of runups on the ramps and everything checked out. We put the cowlings back on, taxied out to the hold short line, did a run up and the plug on #4 left mag wasn't firing (I love my engine analyzer). Pulled cowling, checked plug (top of cylinder) and it was not fouled.

Very frustrating. Could be something deeper in the mag; could be the wiring harness; could even be the plug. But I'm getting very tired of the time and expense of swapping parts. Plus I need 100% confidence in this engine to fly IMC, night, long xcountries, over mountainous areas and water (not necessarily all at the same time, though).

So this situation plus various aggravating oil leaks have driven me to consider having this whole engine rebuilt with less than 1500 hours SMOH even though it is strong and has high compressions.

Advice on such a rebuild are welcome.
Click to expand...


Bite the bullet, throw the mags away, and buy new. Might be cheaper in the long run even.
 
The analyzer gives you vertical columns showing EGT for all 4 cylinders. On the left mag only check the temp dropped way low on #4 (and of course the engine ran rough). so I knew the culprit was the plug on #4 fired by the left mag.

In flight (at least in LOP operation) if you lose one plug, the EGT on that cylinder will shoot up.
 
Henning said:
Bite the bullet, throw the mags away, and buy new. Might be cheaper in the long run even.
Click to expand...


Might be a good idea but I would troubleshoot more - shame to spend 2K on a d-mag when it might be a $300 harness.
 
At annual this year, we found a bad connector on the mag block. I don't know whether it would have been discovered or not as I had the impulse coupling AD done at the same time.

At the time Bendix was quoting 45-60 days for an overhaul (and $1500). Ouch. We replaced the affected parts, reset, and retimed it.

I have the dual mag system also.
 
Let'sgoflying! said:
Might be a good idea but I would troubleshoot more - shame to spend 2K on a d-mag when it might be a $300 harness.
Click to expand...

True, but with the new mag you get the harness as well. It's just that a bad harness won't eat points the way he experienced, and I've seen plenty of problems with those units, and more money wasted in diagnostics (not to mention time and loss of use) and ending up in..... you guessed it, throwing them out and putting in new ones. My comment comes from those experiences with the dual mag units. I saw it nearly bankrupt a 135 carrier with a Chieftain once, not just the $15k he spent changing fuel controllers and prop governors and... (surging at high loads), but missed flights on a contract.
 
Lance F said:
The analyzer gives you vertical columns showing EGT for all 4 cylinders. On the left mag only check the temp dropped way low on #4 (and of course the engine ran rough). so I knew the culprit was the plug on #4 fired by the left mag.

In flight (at least in LOP operation) if you lose one plug, the EGT on that cylinder will shoot up.
Click to expand...

I have a 1981 201 with an EI analyzer. On a trip Sat. I was getting a low EGT reading on #3 during climb out. Once I reached cruise and leaned it was still 20-30 degress lower than normal. It jumped up and down 20-30 degress for about 2 hours. It never got up to normal (stablized) until after about 2 hours. The engine seemed to be running just fine. I thought maybe I had a bad probe? Now I'm not sure. Any ideas?

I have had this plane for about 75 hours. I had problems with the mags when I first bought the plane and I got stranded the second time. Once I got the plane home I replaced the dual mag and it's been fine since. I pay close attention during the mag check.
 
Henning said:
True, but with the new mag you get the harness as well.
Click to expand...

That's not what I understand. If you buy a reman. or new mag you just get the mag body. The mag cap comes with the ignition harness installed and is sold separately.


The link to www.2aps.com had prices of about $165 for the wiring harness (with a core charge until they got your old cap back) and $635 for a reman mag (also plus core charge.) Doing both would be less than a grand. Granted that's a whole lot less than a rebuild for the whole motor. I and my bank account thank everyone for calming me down.

and Dave, we completely complied with the SB shown in the other link you provided. thanks
 
Lance F said:
The link to www.2aps.com had prices of about $165 for the wiring harness (with a core charge until they got your old cap back) and $635 for a reman mag (also plus core charge.) Doing both would be less than a grand. Granted that's a whole lot less than a rebuild for the whole motor. I and my bank account thank everyone for calming me down.
Click to expand...

I would go for it, that would be the fastest and best long term fix, that is a great price. You have too many doubts about the system and this would settle it.
 
"We put the cowlings back on, taxied out to the hold short line, did a run up and the plug on #4 left mag wasn't firing (I love my engine analyzer). Pulled cowling, checked plug (top of cylinder) and it was not fouled.'

Lance I'm not the sharpest GA mechanic but my Lycoming operator's manual diagram for a dual mag shows the LH mag firing the bottom plug in #4 cyclinder not the top. Might want to just swap top and bottom plugs and see if it follows. Just a thought.
Ron
 
L10MAN said:
"We put the cowlings back on, taxied out to the hold short line, did a run up and the plug on #4 left mag wasn't firing (I love my engine analyzer). Pulled cowling, checked plug (top of cylinder) and it was not fouled.'

Lance I'm not the sharpest GA mechanic but my Lycoming operator's manual diagram for a dual mag shows the LH mag firing the bottom plug in #4 cyclinder not the top. Might want to just swap top and bottom plugs and see if it follows. Just a thought.
Ron
Click to expand...
IME, it's not all that unusual to find plugs wired different than what the service manual shows as well as the P leads swapped (L vs R). Don't just assume that everything is by the book.
 
Lance F said:
The field repair made to get me out of Virginia after my in-flight engine stoppage was the replacement of both sets of contacts in my dual Bendix mag. Since the contact gap had been checked during annual only a couple of weeks previously, I was concerned as to the cause of the rapid wear (contact point gap from .016" to 0" on BOTH sets in less than 5 hours!). So we checked mag capacitors (within spec but replaced anyway), continuity of P-leads to ground (OK), and reset timing. Yesterday, did a series of runups on the ramps and everything checked out. We put the cowlings back on, taxied out to the hold short line, did a run up and the plug on #4 left mag wasn't firing (I love my engine analyzer). Pulled cowling, checked plug (top of cylinder) and it was not fouled.

Very frustrating. Could be something deeper in the mag; could be the wiring harness; could even be the plug. But I'm getting very tired of the time and expense of swapping parts. Plus I need 100% confidence in this engine to fly IMC, night, long xcountries, over mountainous areas and water (not necessarily all at the same time, though).

So this situation plus various aggravating oil leaks have driven me to consider having this whole engine rebuilt with less than 1500 hours SMOH even though it is strong and has high compressions.

Advice on such a rebuild are welcome.
Click to expand...


no advice other than ugh, I feel for you. what an expense.

is there any chance the gas was fouled?
 
I'd recommend a new Slick harness. It comes with the cap installed. "Street price" ought to be about $265. If you need a mag I have an Electrosystems O/H that I'd like to say goodbye to. I doubt if your problem is the mag itself. My rule of thumb on the Siamese mag is that it should be have an IRAN at 500 hours by someone VERY familiar with it. Overhaul at 1,000. Charlie Melot Zephyr Aircraft Engines
 
zephyr said:
I'd recommend a new Slick harness. It comes with the cap installed. "Street price" ought to be about $265. If you need a mag I have an Electrosystems O/H that I'd like to say goodbye to. I doubt if your problem is the mag itself. My rule of thumb on the Siamese mag is that it should be have an IRAN at 500 hours by someone VERY familiar with it. Overhaul at 1,000. Charlie Melot Zephyr Aircraft Engines
Click to expand...

Charlie,
A Skytronics harness with cap installed is $165. What could Slick be doing that's so much better?
If I still have issues after putting in a new harness, I'll call about the mag you have.
What does IRAN mean?
Last question (sorry for my curiosity this morning) If you do a rebuild and the owner has very recently (say within the last year and 100 hours) replaced with new or rebuilt some of the accessory things that are normally replaced at rebuild, like a wiring harness, starter, oil/fuel hoses, and/or mags, would you still require that they be redone again? Or would your rebuild price be less to reflect that these don't need to be redone?
Thanks
 
Lance F said:
Last question (sorry for my curiosity this morning) If you do a rebuild and the owner has very recently (say within the last year and 100 hours) replaced with new or rebuilt some of the accessory things that are normally replaced at rebuild, like a wiring harness, starter, oil/fuel hoses, and/or mags, would you still require that they be redone again? Or would your rebuild price be less to reflect that these don't need to be redone?
Thanks
Click to expand...

Not Charlie by a long shot but some items are required to be overhauled or replaced when the engine is overhauled. I don't think the magnetos are in that category, but I could be wrong. As long as it's not, I would expect an overhauler to be willing to inspect your magneto (for a small fee) and re-install it if that was your desire. Of course you shouldn't expect warranty coverage on the magneto then.
 
Lance F said:
That's not what I understand. If you buy a reman. or new mag you just get the mag body. The mag cap comes with the ignition harness installed and is sold separately.


The link to www.2aps.com had prices of about $165 for the wiring harness (with a core charge until they got your old cap back) and $635 for a reman mag (also plus core charge.) Doing both would be less than a grand. Granted that's a whole lot less than a rebuild for the whole motor. I and my bank account thank everyone for calming me down.

and Dave, we completely complied with the SB shown in the other link you provided. thanks
Click to expand...

Sorry I wasn't clear on that, I meant you get them both, not that they both come together. Make sure that reman includes new coils.
 
lancefisher said:
Not Charlie by a long shot but some items are required to be overhauled or replaced when the engine is overhauled. I don't think the magnetos are in that category, but I could be wrong. As long as it's not, I would expect an overhauler to be willing to inspect your magneto (for a small fee) and re-install it if that was your desire. Of course you shouldn't expect warranty coverage on the magneto then.
Click to expand...

When had my overhaul done the mags only had 300 hrs since new. Engine shop had no problem inspecting and re-installing them. Big shop or factory might be different.
 
E-mail JPI and they may be able to repair your bad file from your flight. I have had problems with bad files from one of our club planes, and they are working with me on fixing the problem.

Laura Herrmann
Maintenance Director
Twin City Cloud Seven Flying Club
 
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