Tuesday, July 5, 2011
When we’re our own worst enemy
The subtle differences that are encountered when transitioning from a high-wing to a low-wing, or vice versa, will challenge our muscle memory, which in turn affects how we control the airplane.
New Airplanes: Wow, This Is different!
When checking out in new airplanes, our experience (or lack thereof) can work for us or against us.
When we're students, we know flight only as interpreted by the airplane in which we're learning. Every little thing our instructor pounds into us is specific to this single flying machine. Although, airplane to airplane, the concepts of control are basically the same, it's not until we get ready to fly our first new airplane after earning our PPL when we realize that the nuances of controlling that specific airplane have become ingrained in our subconscious thought patterns.
When checking out in a new airplane, that muscle memory is usually so strong that it takes conscious effort to overcome it and not let our hands automatically make motions that may not be suited to the new bird.
All of us remember our first high-wing to low-wing, or vice versa, transition. The stage is initially set by the overall strangeness of having the wing located where it isn't supposed to be. Intuitively, we know new scenarios are about to unfold. What we don't know is that some differences represented by the new scenarios won't be procedural but will be in the form of perceived differences in the way the airplane feels and how it reacts. And these subtle differences challenge our muscle memory.
If we learned in a Cherokee, for instance, and are transitioning to a 172, the small difference in wing loading between the two makes itself felt. Even though we don't actually know what's causing the difference, we definitely feel it, and it affects how we control it. Initially, we feel as if we're transitioning from a rock-solid airplane (the more heavily wing-loaded Cherokee) that plows through the air, to one that floats on the air, courtesy of the Cessna's lighter wing loading and higher aspect ratio. When we move our hands, we get a subtly different result. It sometimes takes several hours before we overcome the muscle memory that makes us expect one kind of result, when we get another.
One of our biggest surprises during that kind of transition comes when we turn final and drop full flaps. Piper-trained pilots are almost always caught unaware by the much larger pitch change the Fowler flaps on the Cessna produce. They're also surprised when they make the first full-flap approach and find that Cessna flaps really do work: During the flare, they have to be careful not to let their hands automatically pull the nose up at the same rate they would a Piper and cause the airplane to balloon. At the same time, with full flaps, it's all they can do to get the nose up for a main-gear touchdown. Conversely, Cessna-trained pilots wonder if the flaps on the Cherokee even went down, as they habitually start to move the yoke and reach for the trim, then realize a) the trim isn't where they reached and b) they don't need nearly as much trim anyway.
Repetition gives our muscles internal routines that can work against us in new situations.Our muscle memory can cause us heartburn while doing even basic tasks, like making a simple, garden-variety turn in a new airplane. If by some stroke of luck, the newly minted pilot learned in an Aeronca Champ or something similar, he's going to find turning a Cherokee or a C-172 to be an exercise in restraint. The Champ taught him to "lead" slightly with the rudder, so a fair amount of rudder went in more quickly than the ailerons. This helps keep the overabundance of adverse yaw under control. His Champ instructor drilled this into him from day one, but his 172 instructor will have to drill it out of him. And that kind of tiny muscle memory is very difficult to unlearn.
Oddly enough, newbie pilots may transition to a new airplane easier than those with more experience in a given type, because a new pilot's habits aren't as deeply ingrained. Having 100 hours in a Cherokee and then transitioning to a Cessna while still a very malleable, low-time pilot is one thing. Having 500 hours in the same airplane and transitioning can be something entirely different.
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