If you’ve been flying for much time at all, you’ve probably noticed that a significant portion of flight training is dedicated to handling deviations from the norm (or the “abnorm” as I have coined it).  A classic example is when your instructor pulls the throttle out while in cruise flight, simulating an engine failure. “You’ve just lost your engine. Now what?” And while there are checklists for a whole bunch of emergency procedures, troubleshooting a problem often requires an understanding of how a system works. For example, understanding how a carburetor works might help you link a slow decline in RPM to carb icing. For all of the normal, regular things you do in the cockpit, a good question to ask yourself is “how would I handle this if it doesn’t happen like I’m used to it happening.” Let’s look at a few examples to gain a deeper understanding of what “out of the norm” looks like.

Control Surfaces
During preflight, we get into the habit of checking for the same things each time around the airplane. And that’s a good thing. That means that everything is in working order. Such repetition without any occurrence, though, can lead to cutting corners and paying less attention if you aren’t careful. As a student pilot, I always wondered what a control surface looks like that doesn’t check out. It’s important to look carefully and to know exactly what to look for on your particular airplane. Details like the cables and cotter pins being in place take some extra observation – sometimes crouching low or getting on the ground to properly see them. Take a look at this picture of a pin starting to work its way out of an aileron.

Cessna Aileron Pin Loose

Photo contributed by Scott Wilson of Aloha Skies Aviation


Fuel Sump
Of the many things required to make a flight successful, fuel is fundamental. It’s not good enough just to ensure you have fuel in the tanks, though. Not having the right fuel, or the even the right fuel being contaminated, can cause big problems for the flight. Since day one, I’ve obtained a little sample of fuel, held it up against something white to see it’s light blue color, smelled it to make sure it smelled like avgas (which I love – is that just me?) and checked the bottom of the container for any debris or water. I’ve been fortunate not to have any fuel problems, but that means I can’t tell you exactly what to look for in the fuel sample, other than what I’ve been told. Take a look at this picture of some water in a fuel sample.  Water sinks, and this is an example of a whole lot of water, but it could just be little beads at the bottom to look for.  There are stories where the plane runs fine until just after takeoff, where the water in the fuel gets into the engine and causes it to quit.  Engines don’t like water.  They prefer the hard stuff.

Gats Jar With Water

Photo contributed by Ty Smith


Mag Check
“Checking left mag. Drop in RPM. Back to both. Checking right mag. Drop in RPM. Back to both.” Checking each magneto during the runup becomes a very routine procedure. On the checklist, its common to look for a 50-100 RPM drop when switching to each mag, with no more than 100RPM difference between them. We learn to do that, but what happens if one doesn’t drop RPM? What happens if the difference in drop is more than 100RPM? I listen to Max Trescott’s Aviation News Talk Podcast. Max is an experienced, award winning flight instructor and shares general aviation news and helpful tips on each podcast. On a recent podcast, Max did a fantastic job talking about hot props and magnetos, hitting the “why” behind many different angles of the magnetos. Take a few minutes and listen to it here (episode 13; this topic starts around 11 minutes in). This podcast is one of my regular listens each time it comes out.  The point is to learn the systems deeper to adapt when the norm becomes the abnorm.

Cessna Ignition

Do you ever stop to think exactly WHY you check each mag?


As pilots, we have never fully learned anything. We learn a lot, and can gain proficiency – even mastery – over much of aviation, but there is always a deeper level of learning for any topic. Don’t get complacent with any phase of your flying, whether it’s preflight or in the air. If you feel like you have gained proficiency in an area, or like you are going through the motions, seek out a deeper understanding. Seek out what could go wrong, what deviations could look like, and what more about a system you can learn.  Explore the abnorm so that there’s a better chance that it makes sense like the norm.

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