Safety Publications/Articles


Show and tell

A good demonstration explains not just how, but why

An airplane is on final approach. Inside the flight school lounge, the armchair critics gather at the window, sensing an opportunity for commentary and judgment. But at flare height, instead of landing, the aircraft begins slow-flying a few feet above the runway, left wing held slightly low to correct for a crosswind from that direction. Suddenly the wing rises, and the airplane begins to drift downwind. Then the wing dips slightly again as corrective inputs are made, and the airplane wobbles its way back to its position above the centerline. The end of the runway is now approaching, and the sound of an engine revving to takeoff power fills the office. The would-be commentators shake their heads.

On the next pass, when the airplane reaches flare height, it proceeds to complete the landing. The wheels touch, first the left and then the right main, and a few seconds later, the nosewheel. But then something strange happens. As the airplane rolls down the runway, the nose rises again. For the next few hundred feet, the airplane is rolling only on its two main wheels. Slowly, the nosewheel descends again, and by the time the airplane decelerates to taxi speed, it is rolling on all three wheels.

"Bad technique," one of the witnesses in the window announces. No, he probably couldn't make up his mind whether to stop or do a touch and go, speculates another. Somebody like that should not be out there without supervision, complains the third judge. The fourth analyst poses a question: Does his instructor know he flies like that? No, the instructor couldn't possibly know. Otherwise he'd never let this student pilot fly alone.

So it is with some surprise that this perennial panel of perturbed pilots sees that, when the airplane returns to the parking area, two figures emerge. What's more, they are smiling. The student and instructor burst through the office door in animated discussion. "That was great," the student is enthusing. "Thanks for showing me what happens if I don't hold those crosswind corrections. I never really understood what was going on there. And I promise you this, I'll never again let the nosewheel bang down on the runway after I land. I'll keep that control yoke hauled back until the nosewheel comes down on its own. Amazing how much more promptly the airplane slows down when I do that!" The two never notice the blank stares coming from across the room.

The agenda for this flight lesson, although not to be found on a syllabus-and perhaps not even the subject of a lesson plan until opportunity knocked in the form of the right weather conditions-was nonetheless critical to this student pilot's advancement. The presolo student, confused by the multiple tasks required to land an airplane correctly in a crosswind, needed to see more than just how to do it right. She needed to see the effects of doing it wrong so that the corrective inputs would be meaningful rather than rote adjustments to her flying. In the meantime she had also developed a bad habit of letting the nosewheel thump onto the runway after touchdown, instead of holding the yoke back and letting aerodynamics bring the third wheel down. Her CFI thought that today's moderate crosswind provided a good opportunity to tackle both issues in a single session.

When flight instructors discuss demonstrating maneuvers to pilots, the talk usually focuses on how to perform introductory demonstrations, and then (all CFIs agree) the student should do as much flying as possible. But for demonstration of a maneuver or technique to be comprehensive it must include two elements: showing what happens when the maneuver is flown properly, and what may result if it isn't. How carefully you present any aeronautical subject will be the biggest influence on how well it is understood. A simple, vivid example: Instructors train student pilots to take a fuel sample and inspect it for water or contamination. But how many instructors hand their students a fuel sampler full of watery gas to see if they can recognize the problem? That's not to say it is a good idea to intentionally perform a maneuver badly for illustrative purposes, although on occasion the "This is how I do it, and this is how you are doing it" method of illustration can be constructive if used judiciously.

Flying the final approach in a crosswind using the wing-low method, or the crab-and-switch technique, is a case where trial and error can be valuable. The multiple control requirements involved, the counterintuitive requirement to intentionally cross-control throughout the approach and landing, and then touch down one wheel at a time-upwind main wheel first, then downwind main, then nosewheel-beg for detailed illustration. This is a situation in which a long runway with a brightly painted centerline and five to 10 knots of crosswind can make for a very educational session.

While the critics in the office watched that first approach, a lot of learning was taking place inside the trainer. The student pilot had completed a turn from base leg to final and was stabilizing the approach in the left crosswind. Rolling out wings level, it soon became apparent that the airplane was drifting right of the centerline. The student corrected, with some minor assistance, and continued the sideslipped approach with some right-seat coaching to keep the left wing slightly low, and to maintain a bit of right rudder pressure to prevent the nose from swinging toward the lowered wing. (The phrase top rudder is not recommended.)

The landing wasn't the important thing; the sideslipped approach was. So when the airplane entered ground effect, the student was coached to increase rpm slightly and continue flying down the runway to work the crosswind. "Roll the wings level and watch what happens," suggested the flight instructor. "See how we are drifting to the right of the center line? Notice how quickly the drift stops when you restore the bank angle? But observe that you need to keep the nose pinned over the centerline with right rudder, or it will swing toward the lowered wing. Here's how it looks when you use rudder correctly; here's what happens if you don't."

The instructor had another teaching point up his sleeve, but he had not mentioned it yet. The CFI knew that the student, working intently to master the crosswind approach and showing new confidence and skill, would probably let the nosewheel bang to the ground prematurely after touchdown. But one thing at a time; the student was focused on crosswind corrections at the moment, and as the Aviation Instructors Handbook (AIH) points out in its discussion of the demonstration-performance teaching method: "As little extraneous activity as possible should be included in the demonstration" if it is to be clearly understood. For now it was more important that the student remember to maintain the bank angle and rudder pressure all the way down, and after touchdown to keep the ailerons deflected into the wind.

So when the nose did drop prematurely, the alert CFI simply eased back on the yoke just enough to elevate the nose without leaving the ground, and coached the student to hold it there until deceleration allowed it to come down on its own. As an added bonus, the CFI was able to point out that the student unconsciously was applying correct crosswind corrections during this second flare!

Flying is a learn-by-doing business, as the AIH points out. Countless piloting skills lend themselves to demonstration, and there are times when the demo should include learning the difference between right and wrong. Do not assume that correct performance means that your student would recognize an incorrect execution.

Take coordinated flight. Can a student feel sideslip when making uncoordinated control inputs, or does he merely recognize its absence by a centered slip-skid ball on the panel? A good time to find out is while performing slow flight, where the effects of adverse yaw are magnified. An educational demonstration is to gently bank the airplane to the right in an uncoordinated fashion (no rudder) to show how the heading will change to the left when rudder is not used to offset the tendency to yaw from aileron drag. While doing this, point out that you can feel the sideslipping effect of the induced aileron drag, and observe the compromised control effectiveness of flight at a high angle of attack.

Another example is trimming for a given flight profile: How deep is the student's understanding of this fundamental element of pilot technique? Does he merely use the trim wheel as a cruise-control device, or does he grasp the idea that the airplane will maintain the airspeed for which it is trimmed until a change in configuration is made? Here the appropriate demonstration is to vary power settings after trimming. Show that an airplane trimmed for level flight at 2,200 rpm will climb at higher power settings, and descend at lower power, and will resume level flight at 2,200 rpm if the trim is not adjusted again (or the flap setting changed). Speed will remain the same except for minor oscillations which will soon dissipate. Show this and save your student the many frustrating hours spent by others chasing speed oscillations and making unnecessary trim changes.

Often a student pilot's question is your cue to provide a more complete demonstration of a skill. Such questions frequently take the form "Why do I have to..." suggesting knowledge of the need to perform a task, but confusion about what problem it actually solves. If today is a good time to go out and nail down the issue in question, set aside any previously derived lesson plan for as long as it takes, and seize the chance to relieve your student of a burden of confusion.

Such was the case at the airport this day. While the crowd in the office was comparing notes on the inadequacies of modern-day aviation training, inside the airplane a new pilot had learned to discern right from wrong, and taken a nice leap ahead in learning to fly.

Dan Namowitz is an aviation writer and flight instructor. A pilot for 19 years and an instructor for 13, he resides in Maine.

By Dan Namowitz

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