AOG What a Day!

[gmascelli]

What an Adventure today. The initial plan was to meet up with friends for breakfast in Ocean City, NJ. Mary and I were in the air by 7:30 and arrived just after 8am.

On rollout I pulled back the throttle and 3 Tango Charlie shut down, just short of the taxiway to clear the runway. I had two friends in the pattern behind me so they orbited while I tried to hot start. No luck, she would not start. I tugged clear and then a few locals and the terminal man helped me get the plane to the ramp.

After breakfast she started right up but I felt she was not running normal. Once I had oil temps I did a run up. Right mag was really tough and even backfired, left and both were smooth as could be and made good power.

I shut down and canceled my hop home. Luckily we were surrounded by friends and got a flight home. My girl is on the ramp, away from home and not in a hangar. I am making a 3.5 hour drive with my bride including a ferry ride across the Delaware bay to get my girl covered tomorrow. What a birthday present to
me.

I hope to have a mechanic replace or rebuild my right mag so I can bring my plane home by the end of the week.

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[alim]

What did the mag check look like before take-off when you departed ?
What i don't understand is why the engine would die - your operating left mag should be enough to keep her ticking. And you should ideally have only caught this on a mag check and not because the engine died. Were you full rich on rollout ?

Good call on leaving it there and not flying on a single mag. What was your destination airport ?

Finally - do you have an engine monitor on board ? When you did get it running later and it was running rough - do you know which cylinders were firing and which ones not ? i.e. how do you know its a bad right Mag and not some fouled spark plugs.

 

[gmascelli]

Mag check on departure from ocean city md (KOXB) was perfect, numbers looked great. Made full power, ran as she usually does, smooth and strong.

As I turned off the taxiway at the destination, ocean city NJ (26N), it died. I had just started to lean. I could not restart and had to clear the runway, two planes, who I advised I was dead on the runway, remained in orbit until I cleared. Thankfully both were friends meeting us for breakfast.

I wasn’t flying anywhere on one mag, there is nowhere I have to be that bad. Besides we had three planes available to get us home. I wouldn't do it and would never put my bride in that position.

I do have a monitor and honestly it ran so rough on the right mag I just wanted to shut down. I wasn’t going to restart until I have it looked at. Hindsight, I should have left it on left or both and analyzed what the monitor was showing.

It very very well could be a fouled plug, but there isn’t a shop at 26N and I didn’t have tools to pull any plugs. I hope that’s all it is, I’ll know more when the mechanic fly’s in.

 

[alim]

Well the data is still there on the monitor (not sure which type you have). You can download it and analyze it still

 

[Jaybird]

When I do runup and check each mag, besides the convention of listening for an rpm drop I look at the engine monitor and make sure each cylinder has a EGT temp increase (bump-up on each bar) to ensure each cylinder is firing off that single spark plug. If not, I know i might have a weak or completely non-firing plug.

Second, if I ever have a lousy running mag during runup, then during the mag check at high rpm with only the suspect mag switched on by itself still (left or right), I pull back on the mixture and lean up the engine to heat up the cylinders. Watch the EDM for EGT and CHT increased temperatures while doing so to determine how far to lean. The increased cylinder temp has worked to burn off soot/deposits and more often than not restores the mag to good steady running. Shouldn't take more than 30 seconds.

I have never had to do it with my Commander but in other planes I have done this successfully. Of course I only run full rich for three things: 1. first 10 seconds of a cold start, 2. Take-Off, 3. Go around.

 

[alim]

Mag check on departure from ocean city md (KOXB) was perfect, numbers looked great. Made full power, ran as she usually does, smooth and strong.

As I turned off the taxiway at the destination, ocean city NJ (26N), it died. I had just started to lean. I could not restart and had to clear the runway, two planes, who I advised I was dead on the runway, remained in orbit until I cleared. Thankfully both were friends meeting us for breakfast.

So you went full rich on landing then. I know this is drilled into most students - but that mixture knobs needs to stay leaned on landing.
Only on go-around does the mixture come in , alongside throttle. Else you'd be over-rich on all landings. This sounds more like fouling than a mag right now.

I presume you know which mag, which plug for your engine ?


e.g. TO-360 Left/Right MAGs and Spark plug leads ..

 

[sshore]

The backfire and dying on one mag sounds like an issue with the mag. Could very well be the plastic lobe on the points that rides on the cam lobe has gone bad - very common on these types of mags and they basically make the engine way out of time and "unrunable" on that one bad mag.

Now, the above being said, it should not have died on roll out after landing, so your other mag may be weak as well. I would check both of them.

I would bet that your mag is going to be shown to be timed correctly (in other words not "slipped" on the case) and those points may be the issue.

 

[sr30sb]

Gary, so glad this ended differently than your last engine issue.

 

[gmascelli]

The backfire and dying on one mag sounds like an issue with the mag. Could very well be the plastic lobe on the points that rides on the cam lobe has gone bad - very common on these types of mags and they basically make the engine way out of time and "unrunable" on that one bad mag.

Now, the above being said, it should not have died on roll out after landing, so your other mag may be weak as well. I would check both of them.

I would bet that your mag is going to be shown to be timed correctly (in other words not "slipped" on the case) and those points may be the issue.

First report in, right mag toast. Opening up the left mag and they will report back. Pretty much on the same page Stephen, weak left mag. They both have @400 hours. I said any issues replace the left, I rather two new then rebuild.

 

[gmascelli]

gary, so glad this ended differently than your last engine issue.

me too!!

 

[gmascelli]

So you went full rich on landing then. I know this is drilled into most students - but that mixture knobs needs to stay leaned on landing.
Only on go-around does the mixture come in , alongside throttle. Else you'd be over-rich on all landings. This sounds more like fouling than a mag right now.

I presume you know which mag, which plug for your engine.

I have always landed full rich unless higher elevation dictates leaning for best power. Yes, familiar with mag/plug mapping. I like your attachment, adding that to my binder I keep in the plane. So much easier then bringing up the Lycoming manual online

I did go back and watch my video. The plane went quiet before I touched the mixture or throttle. I should know more tomorrow when I talk to the shop. I hope to have our plane home Thursday.

 

[Jaybird]

Are your mags Bendix or Slick Gary?

 

[sshore]

If you have Slick mags, 400 hours is a little early to have problems, but unfortunately not unheard of. Those mags as are junk in my opinion. And lots of problems with points lately (past 1-3 years) according to the guy that re-builds mine.

One reason I went with an Electroaire on one mag bank (among several other reasons).

On my Sundowner, I had the Slick mag go out (caught it on a mag check on run up) and the airplane backfired and ultimately died when checking that mag. When I went and checked the side with the Electroaire, there was zero RPM drop and no noticeable difference in how the airplane ran on the one "mag" (Electroaire).

 

[gmascelli]

Are your mags Bendix or Slick Gary?

Slick

 

[gmores]

Gary - since you have to rebuild/replace a mag anyway, perhaps a good time to think about an Electroair system?

 

[gmascelli]

Gary - since you have to rebuild/replace a mag anyway, perhaps a good time to think about an Electroair system?

3 Tango Charlie has the Slick Start STC. I may consider that upgrade in the future if the left mag needs replacing. The crew doing the repairs called and my plane is ready to go. She needed a right mag only, the left side checked out fine.

If I have any hot start issues moving forward I am going to have that left mag checked again along with the coupler. Maybe then I’ll invest in the Electroair.

 

[alim]

gary - it would be nice to have downloaded engine monitor data.
Ideally shared - so we can learn and see what the data was showing during and before the failure - i.e. was there a way this could be predicted or it went kaput suddenly.

thx

 

[gmascelli]

gary - it would be nice and downloaded the engine monitor data.
Ideally shared - so we can learn and see what the data was showing during and before the failure - i.e. was there a way this could be predicted or it went kaput suddenly.

thx

I’ll work on downloading that info and posting.

I flew our plane home today. The right mag was replaced with a new Slick 4370, the left checked out good and the timing was checked and set on both. 3Tango Charlie made good power and was an easy start. It was good to get the plane home so I don’t have to take the ferry across the Delaware Bay again.

 

[plight]

Good to hear that you found the source of the problem. When it's time to overhaul the other Mag, you might want to consider a Solid State Mag.