FLYING Magazine

Work rounds in Dallas complete before the summer sunrise, I was headed for the hills to meet up with my family. They were already there, in the western Rockies near Angel Fire, New Mexico.

My birthday eve had started perfectly. I beat the Redbird tower operators to work, so while taxiing my seasoned but beautiful 1961 Beech Baron A55 to the departure end of the runway, only the pre-takeoff checklist and a quick turn separated me from my family and birthday bliss. 


The run-up was good and the August sun was about to pounce, so I turned the Baron in a circle to check for traffic. There was none, but I noticed the left oil pressure needle dipped, no, plunged, to almost red line while the right needle remained steady. I’d never seen that before, but I had never done a clearing turn on the ground in the Baron before either. On completion, the left needle crept sheepishly back through yellow into green.

The perfect morning was no more. As a teen, my initial flight instructors all had admonished me to listen to and trust your instruments. I couldn’t ignore them now. Surely the same pirouette in the opposite direction would put it on the right engine, I reasoned. “Must have done it wrong the first time,” I justified. The repeat left needle dip dipped me too. My left engine was whispering to me.

Analog engine monitors (aka steam gauges) provide more information than just digits, so I kept them. They live next to my awesome digital JPI EGT monitors. The side-by-side analog needles offer a beautiful visual control—left versus right—though I know digits are more precise. In-the-green and matched needles are welcome signs of locomotion health while wiggling, sagging, or even just diverging needles are harbingers of bad. The newly sagging left engine needle was not good.

So I returned to base.

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Adding a half gallon of oil to the left engine corrected nothing. Then the weekend mechanic helper performed a full oil change: “No metal seen, sir.” But that only made the needle sag on turning seem worse. The simple fix was no fix, so neither flag nor light was needed to prescribe the next step. I scrubbed the flight. If Plan B is unappetizing, Plan C, D, or E is even less so. This characteristic makes acknowledging and addressing a problem midstream harder still. A consultation was obtained. Alfred “Lucky” Loque has been an A&P since 1969, NTSB accident investigator, FAA A&P seminar leader, and earned the 2009 FAA Technician of the Year and 2022 FAA Charles Taylor Master awards. Most fortunately he is my friend and, on this occasion, my consultant.

Loque listened to my story politely and interactively. The needle dip upon clearing turn—either way—piqued his interest. Then I recalled that two new cylinders were installed two years ago. With resolve, he declared, “You’re grounded! There’s got to be some metal in that oil at least partially obstructing the circulation.” When Lucky grounds you, you’re grounded. I phoned my family. No one was surprised.

Safety is tedious, redundant, and usually boring. Safety mucks up your plans and then the plans of others too. That makes you the opposite of cool. The last part gets a lot of us pilots in trouble, so heeding the inconvenient signs of an unsafe airplane is painful but paramount.

Pulling the trigger on pulling the engine was easy, however. Ten days later and a few bucks lighter, I was happily back in business with a new less-old engine and a fresh prop overhaul.

Lucky later invited me to view the IO-470 autopsy. I hardly slept the night before. In his dissection suite, the fall Texas sunshine showed me plainly the previously obscured metal filings. I was truly surprised, but that belied my mechanical ignorance. He then showed me the means of failure, a beautifully straight groove in the recently installed cylinders. I still didn’t really understand, so he handed me a corresponding piston to demonstrate the rings’ malposition. They were all lined up on the groove.

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While I had recognized warning flags in a blink on the morning of my canceled flight, now I could see the root of it all. Correct installation of the cylinder rings would have put their gaps at different positions to reduce wear. The errantly installed rings had hewn lines of irregular mayhem inside my cylinders in just a few years.

It’s a boring story but it matters. I saw something outside the box on a routine check that made me uncomfortable—and I acted. Furthermore, I believe a digital representation could have easily been ascribed (by me) to some kind of “interference.” With the emphatic needle dip during the turn, I acted.

How we recognize and treat data incongruity is important. We spend lots of time building our experience of normal flight operations so that when something is not normal, we can recognize it. Checklists are an important part of that practice. Running checklists is a form of forced recognition, but an effective checklist requires not only the recognition but a notion of what “normal” is. In addition, iterative problems or emergency checklists explicitly map out what should be done in specific responses or cases. We are good at running these on certain emergencies and abnormal findings, but we are not quite as good at managing things abnormal and outside our mental algorithms.

In his book Human Error, James Reason divided most of what we know as errors into slips, lapses, and true errors. In addition to this characterization, Reason made the point that when a mental problem-solving algorithm has been run even twice without yielding a solution, then our ability to correct the issue regresses to that of a novice. Examples are all around, the bobbled double-play ball at shortstop, looking for your lost billfold in the same drawer again, and shooting the same approach three times. Novice-level performance.

In the book Blink: The Power of Thinking Without Thinking, Malcolm Gladwell addresses how we quickly become biased during activities that ostensibly involve methodical or boring thinking. Gladwell illustrated how that bias—most often from outside signals—can lead us, for better or worse, to action. I submit that an unstable approach or run-up with unusual sounds may be a paradigm that fits Gladwell’s model of bias then action.

Analog gauge needles lend themselves to subtle human interpretation in a blink, even without a warning light. Their great advantage is that they depict information through shapes, angles, and movement that we need not mentally reconstruct to understand. I say this while also ascribing to the great utility of digitized data for detailed analysis, but often ex post facto.

In my boring story, the mismatched needle movement caught my eye. The finding was peripheral to what I was doing, but I stopped because something just wasn’t right. That reaction isn’t in the AIM or POH, but it is critical to safe operation. My instructors drilled into me that when “the instruments talk to you, you must listen,” and they were whispering to me.

Lucky said I was lucky—and he was right. I was lucky to have a job and family that afforded me the opportunity to have an airplane and go to the mountains. I was lucky to incidentally observe an unusual sign on a clearing turn that I’d never performed before. Then I was lucky to have had the insight to stop.

But was it luck? I think that it isn’t luck at all. It is good, deliberate training and experience. So train, train, and then train some more. Repetition is good. You play how you practice, and experience counts.

The gauges are talking. You should listen to them.

Baron Hamman is a 1,000-hour private pilot with instrument and multiengine ratings who learned to fly through the Boy Scouts in Kentucky.

This column first appeared in the March 2024/Issue 946 of FLYING’s print edition.

The post When the Gauges Are Talking, You Should Listen to Them appeared first on FLYING Magazine.

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