First Declared Emergency

Old Geek said:
Ted did do a fine job. I'm wondering where I would have given anyone the idea that I thought otherwise.

My issue has nothing to do with his decision. My issue is that it looks like an aircraft engine has been designed that doesn't run worth a damn on one set of plugs. And nobody else seems to feel that this is an issue. Well, I did say I'm a newbee. Live and learn.
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Don't read too much into it. I thought your post was a great question. Sometimes its very hard to gauge tone on a web board, no one was questioning you or if they did they didn't understand the "tone" of your question ( can't read faces here best we can do is the emoticons)

Anyway, I guess I'd say the redundancy is there to save your ass rather than to complete you mission.
 
A little more insight on the extra mag question posed by Old Geek...

Having the dual ignition systems isn't entirely redundancy. Like a second engine, there is a power loss that's expected, and the goal is not to get home necessarily, rather back to an airport. Certified aircraft are allowed to lose up to 15% from maximum available power when a magneto fails. It is NOT intended to allow you to complete your flight. In a single, losing a mag is a real emergency. I have had two magnetos on the same plane fail within 5 minutes of eachother at one point in time. This was on a twin (and on separate engines). On a single, that would mean the fan stops turning. The twin gave us extra options to fly a few extra miles to the next airport without much concern for making it.

This testing of magneto failures is done in a lab on a dynamometer, with a new engine that has all of its parts working as they should. Ignition timing is correct, the engine is receiving sufficient cooling (if not more than sufficient), spark plugs are new, ignition harnesses are new.

The engines on the 310 have 2100 hours (400 past TBO). The spark plugs are new. We discovered with installation of the new mag that the good mag on the plane was retarded 4 degrees (set at 18 vs. 22). Cooling was sufficient. But it certainly wasn't as ideal a situation as Continental tested this engine to some years ago. The goal is not to get home safely with your second mag, just like you wouldn't continue flying to your destination with only one engine. The goal is to get you safely back to the earth (at an airport) and give you options besides "Land in the nearest available field. Oh wait, there's only mountains. This is going to hurt..."

As to the roughness question: When a cylinder stopped running, it wasn't actually terribly rough. I noticed it mostly on the JPI. The roughness was very abrupt and harsh, which is part of what concerned me. I'm not completely sure what it was. Perhaps the ignition was firing terrible out of time, or some other abnormality caused by the situation.

And there's only one person on this forum who gets to see me without pants. ;)
 
Ted DuPuis said:
And there's only one person on this forum who gets to see me without pants. ;)
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Yeah, everybody knows about you and Danos.:rofl:

Re. mag redundancy, I'm guessing that many pilots know of a number of trips that concluded with a bad mag of which the pilot was blissfully unaware until the flight was concluded, and which provided no indication of problem while in flight. I've had more than one such instance.
 
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wabower said:
Yeah, everybody knows about you and Danos.:rofl:

Re. mag redundancy, I'm guessing that many pilots know of a number of trips that concluded with a bad mag of which the pilot was blissfully unaware until the flight was concluded, and which provided no indication of problem while in flight. I've had more than one such instance.
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The Free Bird blew a mag as I was flying it home from Oshkosh. I honestly didn't notice.
 
Nice teamwork, Ted and Laurie!

So, when they asked for fuel and souls on boards, was your answer to the latter 2, or 27?! Would have loved to hear Center's response to 27 souls in a 310....
 
Now I'm sorta new also...so my question is shouldn't each engine have 2 mags so each engine has redundant spark ? If i missed this or read it wrong my apologies in advance !... But either way i understand that when 1 goes, get it on the ground. Good job.
 
Areal, each engine does have two mags. But, as we've learned, when one mag fails that doesn't mean the engine will still run smoothly, depending on the failure mode.
 
wabower said:
Yeah, everybody knows about you and Danos.:rofl:
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Well, we did spend 30 hours out of a 48 hour period in the Aztec... ;)

Re. mag redundancy, I'm guessing that many pilots know of a number of trips that concluded with a bad mag of which the pilot was blissfully unaware until the flight was concluded, and which provided no indication of problem while in flight. I've had more than one such instance.
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Correct. I have had several mag failures in the Aztec that would have gone unnoticed were it not for the engine monitor to tell me the EGTs on that engine had increased. For some reason, the parallel valve IO-540s seem to not really care much. The IO-520-Es in the 310 do seem to care quite a bit more. At least, mine do. It'll be interesting to see what happens when we get the engines overhauled, if anything changes. I'm hoping the change being that I stop having little problems like this.

TangoWhiskey said:
Nice teamwork, Ted and Laurie!

So, when they asked for fuel and souls on boards, was your answer to the latter 2, or 27?! Would have loved to hear Center's response to 27 souls in a 310....
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"2 humans and 25 dogs"

I think they ignored the dogs.

arealrider said:
Now I'm sorta new also...so my question is shouldn't each engine have 2 mags so each engine has redundant spark ? If i missed this or read it wrong my apologies in advance !... But either way i understand that when 1 goes, get it on the ground. Good job.
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Check post 42 for more detail.

I think that many people confuse "redundancy" in aviation somewhat. It doesn't necessarily mean that you will be operating at 100% capacity in the event of a failure. What it means is that, when something breaks, you still have a backup that gives you more options. A magneto is a good example, and one that varies significantly from engine to engine as to the impact of a magneto failure.

True redundancy means no diminished capacity in the event of a failure. So for example, if you had an electrical system that had a maximum draw of 75A and you had two 100A alternators, your charging system would be redundant. However, most aren't that way. If I lose an alternator in the 310, for instance, and try to operate the heater, avionics, pitot heat, prop heat, and nav/strobe lights, I'll start to notice a voltage drop. So now I need to decide what to shut off to run on the one alternator. If I'm in an icing condition, pitot heat and prop heat are on the bottom of the list...
 
Alright people, we can stop focusing on my pants now. :)
 
Alright people, we can stop focusing on my pants now.
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PantspantspantspantspantsTed's!!pantspantspantspantspantspantspantspantspantspantspantspantspantspantspantspantspantspants!!!!!!!
haha!
 
It's easy to Monday morning quarterback, but the true test of handling an in flight emergency is the outcome. You can't beat a safe landing and an unwrinkled airplane. Congratulations.
 
FWIW -- IME -- the larger six cylinder Continentals are very noticeable when you're running on one mag (alarmingly so). OTOH -- a 4 cylinder Lycoming O-360 .. not so much.
 
Thanks, Ted, for a very useful post. I know that posting something on this board can sometimes be pretty discouraging when the "experts" start piling on. I have learned a lot from this thread and want to let you know. And for anyone else who is hesitating to share something that might become controversial, we learn a lot from this kind of honest reporting.

PS. I think you did everything right.
 
I was happy about the lack of Monday morning quarterbacking here, and it seems like the intent was realized - a useful thread to provoke thought and question.

And if people are being jerks (rather than providing constructive questions or comments), my skin is thick. :)
 
jesse said:
FWIW -- IME -- the larger six cylinder Continentals are very noticeable when you're running on one mag (alarmingly so). OTOH -- a 4 cylinder Lycoming O-360 .. not so much.
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Maybe not "all"... ?

I've done in-flight mag checks on my O-470 and other than the reduction in power, there was nothing alarming. Probably wouldn't climb worth a crap on one up here... but it doesn't vibrate, cough, or behave badly at all.

If the bad mag were doing naughty things, it'd probably rattle my teeth out though. It's smooth if the failure is symmetric and all the plugs on that mag are truly dead.

Get asymmetric with it and then it'll shake like hell. When the plug wire cap broke off on the ground on one cylinder at KLBF last summer, that was one heck of a shaky run-up as I tried to "burn off" what I thought might have been a fouled plug. Eyeball shaker. Two short "burn off attempts" was enough for me.

I also should'a known since you saw me religiously ground-lean it, that wasn't a fouled plug. No JPI so there's not much to "see".

I can attest that an O-470 firing full on five cylinders and half on one cylinder will shake the crap out of everything aboard though. My plastic bottle of Diet Coke tried to explode on the ramp after we got out and went looking for a mechanic. ;)
 
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