dead reckoning
It’s always a good feeling when you can correct the teacher.
I was only in my mid-20s, but I was already considerably farther along than the other students. There were a handful that matched my age, but most were still pimply-faced teenagers, straight out of high school, and didn’t have my life experience, or more significantly, my mechanical experience—both practical AND theoretical. I’d simply steeped myself in the knowledge of the inner workings of aircraft (and cars) for most of my life, and had actually rolled up my sleeves and gotten to know cars in particular in a hands-on way for the better part of the previous decade. So obviously, the more technically focused sections of the private pilot’s license curriculum weren’t that much of a challenge for me (learning to fly by feel was—but that’s a post for another day). At the end of the first semester, we took the written part of our license evaluation, and Mr Hahn promised a steak dinner to anyone who received a perfect score. I was crushed that I only missed one question. So close.
The practical test—the checkride—came at the end of the second semester. Prior to the checkride, we’d have one final evaluation with the lead instructor, Mr Kelly: The dreaded final stage check. I say “dreaded” because the entire purpose of the exercise was for Mr Kelly to nitpick every little misstep and discrepancy in our technique, with the idea that the checkride itself would be less stringent in comparison, and so the stage check would take the edge off, as it were. How that worked out in general practice, I’m not sure, but I do remember being equally nervous for both…
In any event, for the stage check, the day was crisp and perfectly clear. The little Cessna 172 was fueled up, waiting on the ramp. Mr Kelly, clipboard in hand, gestured me over to the plane, and I completed the preflight by the book. I hadn’t flown with him before, but he had a reputation as a gruff, demanding instructor who tolerated little deviation by his students, but produced highly competent pilots. I was intimidated, but went through my checklists, started the plane, and taxied to the runway. So far, so good. The wind was northerly, so the plan was to take off on runway 2, over the 50-foot trees just north of the threshold, fly to the practice area, and do whatever exercises he told me to do with the aircraft (presumably some slow flight, stalls, turns around a point, flying on instruments, and so on). I back-taxied down the runway, swung the plane around, made the appropriate radio calls, and gunned the engine. The little Lycoming roared, and we were on our way, hurtling down the runway and up into the air. On instrument panel, there were a whole host of switches and knobs, and two that controlled the engine: The throttle and mixture knobs. For takeoff, per procedure, I had set the mixture knob to full rich (all the way in), when I advanced the throttle (also all the way in). Standard protocol dictated leaving the mixture on full rich all the way up to cruising altitude, which, on that day, would likely have been somewhere between three and four thousand feet. At that height, the air density is less than at sea level—not much less, but a measurable amount. I knew, from my mechanical experience, that an internal combustion engine runs best at a certain air/fuel ratio: Typically 14.7 (air) to 1 (fuel), or a little leaner (less fuel). So, as the plane climbed, and the air thinned ever so slightly, I instinctively reached for the mixture knob and backed off the fuel a little bit, just to help maintain the right ratio for optimal engine performance.
“What are you doing that for?” barked Mr Kelly.
“Just leaning out the mixture a little since we’re going up in altitude,” I stammered.
Silence.
“Push that knob all the way in and keep it there.” Mr Kelly finally retorted.
I complied, and remained focused on my instruments and the task at hand, but from the tone of his voice, if I had had the capacity to be able to glance over at his face, I have a feeling I would have caught a smile.
And I did pass the stage check.