In-flight LOP Mag Check (video)

[Martin Pauly]

Periodically, I see questions on the forums about in-flight lean-of-peak (LOP) mag checks. This video is an attempt to explain what they are, why you want to do one, and how exactly to do that.

 

[EdFred]

So what happens (like it did to me on a fail mag) when you do the mag check in flight, and the engine quits? Yes, it can happen with certain mags. Not all stay hot. Resuming the spark with an exhaust full of fuel vapors is not a good recipe.

 

[Rcmutz]

What if I can’t fly LOP? My engine is carbureted. Is there still value in doing a leaned mixture in flight mag check? Or should mixture be full rich?

 

[Martin Pauly]

So what happens (like it did to me on a fail mag) when you do the mag check in flight, and the engine quits? Yes, it can happen with certain mags. Not all stay hot. Resuming the spark with an exhaust full of fuel vapors is not a good recipe.

I have to ask, did you watch the video? Half of it addresses exactly that problem, and demonstrates a solution that will avoid combustion in the exhaust.

- Martin

 

[Martin Pauly]

What if I can’t fly LOP? My engine is carbureted. Is there still value in doing a leaned mixture in flight mag check? Or should mixture be full rich?

I would do the check with the same mixture setting you use in cruise flight then, which I assume is somewhat leaned but still on the rich side of peak. That will still give you a better (earlier) indication of a problem than the typical ground check.

- Martin

 

[EdFred]

I have to ask, did you watch the video? Half of it addresses exactly that problem, and demonstrates a solution that will avoid combustion in the exhaust.

- Martin

I will admit that I did not watch the video before posting that question.

 

[Stephen Shore]

Great video as usual. I will try this this week while over the airport at altitude. I need to practice steep spirals anyway - been awhile.

Keep up the good videos Martin!