Instructor report: Student fatigue

In some ways, the brain is like a muscle; it can tire out from intense exertion. Learning to fly is essentially two complete strangers trapped in a small box in an environment that presents one of them with so many new sensations and demands that his or her brain often is stretched to the limit trying to cope. The challenge to the CFI is to determine a student’s “tells” that will let the instructor know when mental fatigue is setting in.

Many flight schools and instructors aim for a standardized one-hour flight lesson. However, because of student differences, one hour might be too much. Or it might not be enough, and another 0.1 hour or so would let that student progress further. However, some students are good for only 0.7 or 0.8 before fatigue starts to degrade their ability to learn. So, it’s important to both the student and the instructor to determine at the beginning where this student falls in the still-able-to-learn curve that is determined by their fatigue characteristics. Knowing how to determine a given student’s fatigue state can become especially useful when immersed in high-demand hops such as serious crosswinds or when it’s hot and turbulent. The more demanding the flight environment, the faster fatigue builds.

Learning to fly presents students with so many new sensations and demands that his or her brain often is stretched to the limit.Signs of fatigue may appear gradually or all at once. In the extreme, pilot fatigue shows in two different ways. One extreme is that the student is trucking along just fine and the ability to do a single task suddenly disappears. Maybe airspeed control becomes a problem, or the student can no longer hold an altitude. The other extreme is that, without warning, all of the off-flags pop up everywhere in the student’s skill package and he or she can do absolutely nothing right.

For most people, the factors that tell the instructor that this student is entering the Fatigue Zone are less obvious. For that reason, for the first two or three hours of flight time the instructor has to monitor the student very closely, looking for signs that indicate mental saturation is taking place. Equally important is making sure that frustration at not being able to perform isn’t becoming a problem.

As instructors, we don’t want to keep students in the air so long that they are no longer learning. Frustration will cause them to try harder, which too often sends students into a mental graveyard spiral: The harder they try, the worse they do, and the more intense their frustration becomes. This kind of cycle repeated through a number of lessons can drive an aspiring aviator out of aviation altogether. No one wants to spend that much time and money only to end each lesson hating themselves. That’s not fun. We should always try to end an hour on an up note, not a down note, even if it means stopping well short of an hour after a particularly good landing or session. Let students savor the experience as they’re climbing out of the airplane. A way to guarantee stopping on an up is to avoid keeping the student in the air until they’re worn out. Unfortunately, shortening hops is difficult for both flight instructors and flight schools.

Making a living as a flight instructor or running a flight school is, to put it mildly, difficult. Any business or endeavor that has nothing to sell but time is based on direct labor-hour utilization ratio. Businesses have to look at the number of labor-hours available in a day (potential flying hours in this case) and how many of them are actually being used to generate revenue. In flight training, a small addition of 0.1 hour/flight can make a big difference to the bottom line and fatten up instructors’ logbooks faster. However, there are some students (far from the majority) who simply can’t continue to learn past a certain point, say, 0.8 hour. Tacking on an additional 0.2 hour to bring it up to an even 60 minutes does more harm than good.

Students almost never know when mental fatigue is setting in because physically, they feel fine. They don’t know that a tired brain is causing them problems. Only the instructor knows that, and it’s up to us to adhere to the cliché that, sometimes, “less is more.”