The in-flight Lean-Of-Peak Magneto Check explained

We check the magnetos on the ground during the run-up, before take-off, right? Well... there is a better way to check your airplane's ignition system, a way which is more likely to highlight small problems before they become big enough to ground the airplane. In this video, Martin explains how an inflight LOP mag check works, what makes it better than the ground check all pilots learn to do in flight training, and - very important - the recovery procedure should the test fail.

0:00 Case for change
1:22 LOP mag check demonstration
2:49 What if there is a problem?
4:15 Recovery procedure
6:14 Conclusion
6:58 Outtakes

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[matte]

Thank you for not posting this yesterday. I wouldn't have known how to interpret it.

[wwm]

Martin - I noticed that your % HP was at 70% while you were running LOP - sometime I thought it was better to run LOP at 65% or lower - I have used the LOP mag check in flight but was never aware of how to recover from the possible accumulation of fuel with a dead spark plug - thank for the very simple but clear methods. V35B with IO520 here

[wyflyguy]

Great info. I had never heard of this.

[johnfitzpatrick]

Hello Martin from Sydney, Australia.
Firstly, thank you for this explanation. I now have a better understanding of the ignition system and piston combustion engine used in small planes.
Continential and Lycoming specifications.
With LCD screen and measurements from the sensor, the PIC can identify beyond carburettor icing.
* you said operating lean of peak may take a stronger spark. Do you suggest better plugs, leads or Bendix v Slicks magnetos?
* Considering the power arch statistical graph (Savvy Aviation), each side for rich to lean of peak: air/fuel ratio, exceeding 400 °f and photos show, more pitting is done to piston, cylinder heads, and valve seals which (after a borescope inspection) could lead to a top overhaul: the last thing... a plane owner wants. Simply that's time and money.
🤔👨‍🍳 Happy Easter Captain.

[frontagulus]

Is there a risk of thermal shock doing this in cruise, going from cruise power to no power and with cruise speed air cooling flowing through the engine nacelle

[donalddepew]

This guy is dangerous! Oblivious to the world while talking to the camera during taxi and flying. First of all running lean of peak is like begging for burnt exhaust valves. The only time you should check your mag in flight is when you’re troubleshooting engine trouble. Just because clowney boy here is wearing a Bonanza Society shirt, doesn’t mean he knows S—t. Just another internet hero acting like he knows more than us old boys who have thousands of hours running recips. I wouldn’t fly with him if I were you.