Swiss cheese. Swiss cheese got me in trouble. This isn’t flatulence-related, I promise. The Swiss-Cheese Model is a theory of accident causality often used in studies of aviation accidents. The short version: systems (like aviation) have multiple layers of defense against risk, like slices of cheese. Small errors make holes in those slices (hence Swiss cheese, now, follow along). Each of those individual errors (holes) may not be enough to break the system or cause an accident. But when those holes line up, the result is not good. When NTSB accident investigators submit their final report, the cause is almost never one huge thing, but instead a series of small errors or omissions that led to the accident.
First, let’s go over precisely what happened. Like I discussed previously, an uncoordinated power-on secondary stall was to blame. Don’t I sound fancy using big words to explain how I f*cked up? It went like this:
- We practiced slow flight.
- During slow flight, I trimmed the airplane so I could fly it hands-off in slow flight, perfectly stabilized. This is something I hadn’t really done before; it was a technique recommended by my CFI on my previous lesson. The premise being: why work harder than you have to? Set the airplane up so it flies perfectly in the configuration you need. I never did it in previous lessons, because we were only in slow flight for a few minutes and I didn’t want to have to re-trim afterward.
- We went from slow flight straight into practicing power-off stalls. I did not re-trim.
- We practiced a stall, once the stall occurred, I lowered the nose and applied full power.
- The airplane, being trimmed for nose-up slow flight, not full-power level (or slight climbing) flight, required HUGE amounts of forward pressure on the yoke to hold the nose down. I was not at all prepared for this, as it had never happened before.
- Because I was surprised, I didn’t apply enough forward pressure, the nose immediately rose again, and now we were approaching a power-on stall. At the same time, the wings rolled into slight right bank.
- #4-6 occurred within about 1 second, and my brain never got past a startled/confused state. I was trying to hold the nose down but couldn’t, and was also instinctively correcting the bank with aileron (a big no-no when close to a stall). My aileron corrections to the left were was causing the left wing to stall, and at the same time, the airplane was yawing to the left, which I didn’t notice or correct. The stalled left wing, uncoordinated flight with left-yaw, and the left-turning tendency of the engine at full power, were all too much for the poor little Cessna, and over we went into the beginnings of a left spin.
- My instructor reached over, pulled the power to idle, and took the controls to recover the airplane.
- My instructor shook his head, and I was very sad. 🙁
Check out the video here:
P.S. It looks less startling and scary than it was in real life.
Let’s look at the holes in my cheese (worst pickup line ever):
Lack of Experience
Hey, I earned those 50+ hours. But 50 hours is a drop in the bucket in terms of understanding aviation. The old adage that your pilot’s license is “a license to learn” could not be more true. I know I am ready for this checkride. I know I can handle myself in an airplane. Do I still have the healthiest of respect for the airplane and the air and weather and ATC and other air traffic? You’re damn right. Every single flight I’ve taken, I’ve learned something new. That won’t stop once I get my license, which means I still have a lot to learn.
Checklists are a way of life in aviation. Checklists save lives. But there is clearly a difference between knowing you have to do something, and knowing why you are doing it. The private pilot syllabus, and Practical Test Standards, are designed (ostensibly) to teach a pilot how to control an aircraft in all phases of flight. Sometimes, however, the grind of flight lessons results in the student losing track of the why. Or, at least, it results in too much focus on one characteristic of flight. I was in rote learning mode, instead of practical learning mode. I was thinking about the steps to set up for slow flight, and the steps to set up for a power-off stall, without thinking of the aircraft as a whole, and what was happening to it thanks to all the changes I had made. Specifically, all that trim that I had never used before.
The Book vs. The World
This could also be filed under “Lack of Experience”, I suppose; memorizing something from a book, and experiencing it in the real world are two vastly different things. I knew my acronym for spin recovery: PARE. Power – off, Ailerons – Neutral, Rudder – Opposite to the spin, Elevator – Forward. Did that pop into my mind when the airplane started to spin? Absolutely not. The only thing that would have burned those actions, not just the words, but the actions into my brain would be experience. So, spin training is definitely on my short list of things to get done once I get back into the air.
It reminds me of car brakes in the pre-anti-lock-brake era. Everyone knew, if you locked your wheels and started to skid, you needed to pump the brakes to get the wheels turning again so the brakes would be effective. I once came really close to hitting the car in front of me at a red light. I knew about brake-pumping, but at the time my brain just said “BRAKES = STOP. WE NEED MORE STOP. WE NEED MORE BRAKE.” The tires were locked and skidding, but I just pressed harder on the brake pedal. I literally stood up out of my seat, pulling on the wheel and standing on the brake.
A quick aside here: my instructor knew exactly what was happening. He is a great instructor because he lets me make mistakes, and waits for me to realize it and correct it. If I don’t correct it, only then will he step in to make the correction to keep us safe. He watched this situation develop, knowing exactly what would happen, and waited for me to (hopefully) realize it, and fix it. When I didn’t, he stopped it before it became so terrifying that I might have been too scarred to come back and finish my training.
- I need to think critically about all characteristics of the aircraft in every configuration and all portions of flight. What is the status of all of the control surfaces, what are my power and trim settings, what is the wind doing?
- I need spin training.
- I need to work on my rudder and coordination skills, during all phases of flight.
- I need to do everything I can to break those reflex reactions. I used aileron to correct a bank when I definitely shouldn’t have. But my brain said “we’re banking left” and my arms said “OK, I will bank us right”.
- There are an infinite number of possible scenarios for each flight. Never assume everything will be like it was last time.
I’m being overly hard on myself here, but I want to squeeze every possible lesson out of this. I was incredibly disappointed with myself when it happened. I was so close to finally realizing my dream of having a pilot’s license, and whoosh, it slipped right through my fingers. Now that I have some distance from it, I am supremely grateful it happened during a lesson, and that I have video to debrief with.
Now, I’m going to go make myself a grilled cheese.