Didn't do mag check, and then trouble

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bahama flier

Pre-takeoff checklist
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bahama flier
I topped off fuel at N. Eleuthera, flew to Berry Island, next day flew to Ft. Pierce for customs

I had some trouble getting my airplane out of the tie down area, no designated tie down areas and was blocked in. I was tired and aggravated with the mess, so when I got clear, I cranked up and left.

I noticed my clime was slow, and when I went to adjust my prop speed, the motor would almost stop, my EGT was where I would normally adjust it to, but I had not touched it.

I got to Freeport and noticed I was really sucking down the fuel, considered landing, but Ft. Pierce was an Hour away, plane still flying ok, just sucking down fuel.

Got to Ft.Pierce, a normal 35 gal stop was near 60 gallons. After I cleared Customs, did my mag check and found one dead. I rented a car and drove home.

I survived this dumb ass mistake, and lived. I don't have that many more years till my final time, but I am going to be much more careful not to push it, and to do my proper checks. I now know it works today, not always tomorrow.

Just admitting I let myself do something stupid and it was my fault, and I know better
 
wow! Thanks for sharing. coming from a student pilot I appreciate the story, makes me think even more about checklists.
 
Thank you for sharing this, and I'm glad everything worked out alright, and just cost you some additional fuel.
It's fantastic that we have redundancies in the aircraft with certain things, and maybe that allows mistakes like that to be less painful.

The good thing is, that it will only happen once, and it's already behind you. :)
 
Thanks for sharing. Single engine over that much water is bad enough; doing it one only one good mag is even worse. Getthereitis can be hard to overcome.

Don't be afraid to do an inflight mag check if you suspect something is wrong. Why was the fuel burn increased? That's nearly double the normal rate. I suppose the EGTs were higher than normal since the fuel was still burning on the way out of the cylinder. Do you lean to peak and then richen to 50° rich of peak? Or do you just lean to a EGT value (not typically recommended).

Also, what turned out to be wrong with the mag? Was it easily repairable?
 
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You are to be commended for sharing a situation we all can learn from.

BTW, I check the mags in the air also. ;)
 
muleywannabe said:
wow! Thanks for sharing. coming from a student pilot I appreciate the story, makes me think even more about checklists.
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Yep. I ditto this comment as well. We're always told that those checklists are there for a reason. While we know that to be true as students, stories and real-world scenarios like this really drive the point home. Who knows, your sharing might have saved one of our butts in the future.

Thanks again!
 
Brad Z said:
Thanks for sharing. Single engine over that much water is bad enough; doing it one only one good mag is even worse. Getthereitis can be hard to overcome.

Don't be afraid to do an inflight mag check if you suspect something is wrong. Why was the fuel burn increased? That's nearly double the normal rate. I suppose the EGTs were higher than normal since the fuel was still burning on the way out of the cylinder. Do you lean to peak and then richen to 50° rich of peak? Or do you just lean to a EGT value (not typically recommended).

Also, what turned out to be wrong with the mag? Was it easily repairable?
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If he had done an in-flight mag check in this case, isn't there at least a 50/50 chance he would have killed the engine? Over water?

I think if I suspect a dead mag I'd rather make a landing ASAP to check it than risk a potential engine out emergency.
 
Only if you can't turn the good mag back on.

I'd only do that if there was a decent emergency landing spot around, but it's a whole lot less than 50/50.
 
MAKG1 said:
Only if you can't turn the good mag back on.
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Well, it's at least 50/50 that the engine will quit. (If you turn off the good mag first, engine quits, if you turn off the bad mag first and see no drop, you might not touch the other mag).

What the chances of a restart are, nobody can say. Which is why I'll stand by my statement: Get on the ground to check it.
 
bullwinkle said:
Well, it's at least 50/50 that the engine will quit. (If you turn off the good mag first, engine quits, if you turn off the bad mag first and see no drop, you might not touch the other mag).

What the chances of a restart are, nobody can say. Which is why I'll stand by my statement: Get on the ground to check it.
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I have checked a bad mag in the air, found it dead, and the engine resumes operation just fine when I go back to Both. The prop doesn't stop instantly, especially in flight, and in fact takes some effort to stop it altogether.

The mag switch isn't there just to check the mags on the runup. Mags have been known to go rogue when the distributor gears wear and start slipping and sending the spark to the wrong cylinders at the wrong times. That can kill the engine even if the other mag is fine. You need some means of shutting off a rogue mag, and the mag switch is there for that.

The OP's bigger issue is possibly a lack of 500-hour mag inspections. Too many airplanes get flown until a magneto quits.

Dan
 
bullwinkle said:
Well, it's at least 50/50 that the engine will quit. (If you turn off the good mag first, engine quits, if you turn off the bad mag first and see no drop, you might not touch the other mag).

What the chances of a restart are, nobody can say. Which is why I'll stand by my statement: Get on the ground to check it.
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In some cases such as a timing issue, you're better of on just the good mag rather than both. You won't know that without doing a mag check. The OP mentioned he noticed an issue on climbout so the airport was nearby. Either way, and I'm sure the OP knows this, it's not wise to fly with a bad mag, particulaily if you don't know the cause.

Regarding in air mag checks...yes if one mag is dead the engine will cease to continue producing power...but the prop is still turning. If you want to avoid the pop of igniting raw fuel leaving the engine bring the mixture to idle cutoff before switching to the good mag. One switched, return mixture to rich and lean as necessary. EGTs will be higher on one mag as fuel will still be burning as it leaves the cylinder with only one spark source.
 
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You know, I did consider doing a mag check in the air, but I was afraid of an engine loss all together, plane was flying, all gauges were ok, so I continued on.

The mag failure was because the screws backed out of the mag, and it came apart. The mag was rebuilt, and other was tested, all is well now.

Yes after hours I became complacent in my duties as a pilot, yes I am a dumb ass, but smarter now.
 
Thanks for telling us the story OP.

An old pilot taught me to do a mag check before you fly and before shut down for the day. As he put it "you don't want to stable a sick horse"

Usually, a mag does not just go bad when it's sitting. It goes bad when it's in operation. So checking them before you shut down is a good idea. That way you can get it fixed instead of finding out before the next flight.
 
I guess there are still people out there flying without an engine monitor...even over open water. We'll have to drag you kicking and screaming into the 1980's.
Jon
 
bahama flier said:
You know, I did consider doing a mag check in the air, but I was afraid of an engine loss all together, plane was flying, all gauges were ok, so I continued on.

The mag failure was because the screws backed out of the mag, and it came apart. The mag was rebuilt, and other was tested, all is well now.

Yes after hours I became complacent in my duties as a pilot, yes I am a dumb ass, but smarter now.
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I'm curious: What screws backed out of what part of the mag?

I've experienced a complete mag failure (detected on the ground, during run-up) and it was like a light switch. One day it worked, then it didn't -- poof.

But there were no screws that "backed out".
 
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Its been a long time since I have flown single engine (on purpose) but doesn't the loss of power in flight checklist suggest checking the mags to see if one has failed? It happened to me flying a C-207 in Alaska one time, suddenly lost a lot of power, lots of back firing so did the memory items including checking the mags while in flight. And one had failed, turned it off and returned to base without any more problems. The mechanic found a sheared pin in the drive gear.
 
Thanks for sharing. One mag completely failed on me and I found it during the normal engine run up. That made an impression on me. Stories like yours drive home the point that every item on a checklist is there for a reason.
 
When you do an inflight mag check and turn it to the bad mag, the engine will stop. When you turn it back to the good mag, the engine is very likely to backfire, bigtime, and restart. The backfire may do some damage. If you can figure out that it is PROBABLY a bad mag (decrease in power) it may actually be better to just carry on without a mag check and land at the first possible opportunity. Then do a mag check on the ground. I know there is a temptation to do the mag check to verify your theory that it IS a mag, but.....
 
coloradobluesky said:
When you do an inflight mag check and turn it to the bad mag, the engine will stop. When you turn it back to the good mag, the engine is very likely to backfire, bigtime, and restart. The backfire may do some damage. If you can figure out that it is PROBABLY a bad mag (decrease in power) it may actually be better to just carry on without a mag check and land at the first possible opportunity. Then do a mag check on the ground. I know there is a temptation to do the mag check to verify your theory that it IS a mag, but.....
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See my post #13. Technically it's not a backfire as there is no inginition within the induction system, but it can be harmful to the muffler and exhaust system. Cut off fuel before going to the good mag to restart.

Many folks aren't too interested in doing a mag check in flight for fear of concerning their passengers with a rough running engine. If that's the case, get the plane back on the ground ASAP and do your check there. With only one operating mag, you've lost redundancy, and you have no certainty that whatever caused the first mag to fail won't effect the remaining one too.
 
After all these years of teaching students and doing many thousands of runups, and having the occasional student accidentally turn the mag switch to the "off" position during the mag check, followed by the loud backfire when he immediately turns it back on, I developed this technique:
When you put your left hand on the mag switch, put your right hand on the throttle..
If you accidentally turn off the switch (or encounter a dead mag), immediately pull the throttle to idle, then turn the switch back on. The prop will keep the engine turning.
I have them practice this procedure a few times til it becomes smooth and automatic.
 
nosehair said:
After all these years of teaching students and doing many thousands of runups, and having the occasional student accidentally turn the mag switch to the "off" position during the mag check, followed by the loud backfire when he immediately turns it back on, I developed this technique:
When you put your left hand on the mag switch, put your right hand on the throttle..
Click to expand...
Yep. Standard for me as well.

Although it's not only the occasional student who does it :hairraise:
 
Here's one from the "It's funny what we take for granted" department:

When we bought our RV, I thought it was odd to have two toggle switches for the mags -- one for left, one for right. I vowed to "fix that", with a standard key switch when we redid the panel.

Guess what? After flying with it for a hundred hours or so, I discovered that it was a better arrangement than the key switch, with no possibility of accidentally turning off both mags by turning the key too far. When we redid the panel in February, I left it exactly the way it was.

Sent from my Samsung Galaxy S3...
 
nosehair said:
After all these years of teaching students and doing many thousands of runups, and having the occasional student accidentally turn the mag switch to the "off" position during the mag check, followed by the loud backfire when he immediately turns it back on, I developed this technique:
When you put your left hand on the mag switch, put your right hand on the throttle..
If you accidentally turn off the switch (or encounter a dead mag), immediately pull the throttle to idle, then turn the switch back on. The prop will keep the engine turning.
I have them practice this procedure a few times til it becomes smooth and automatic.
Click to expand...


Some good flying advice in your post.

Backfires are considered not good on something up there in the squirrel cage most every time that's for sure.

If you can learn to cut the throttle before engaging the good mag, that's a good practice. :yesnod:
 
midlifeflyer said:
Yep. Standard for me as well.

Although it's not only the occasional student who does it :hairraise:
Click to expand...

A student is anyone who is always learning.

All of my flights have been training flights to prepare me for the next one.
 
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