Simple cures for common problems
Performing a normal takeoff (as opposed to a crosswind, short-field, or soft-field takeoff) is generally a simple task. After all, the takeoff is just another maneuver, like steep turns or slow flight, but with its own specific objectives and performance standards. However, as with other maneuvers, you may find you're having some difficulties teaching certain elements of the takeoff. Recognizing, analyzing, and correcting these common difficulties is your job as an instructor. If you're a new CFI, rest assured that your student is not the first to encounter these struggles, and certainly won't be the last. To gain some insight into these challenges, let's go over some of the common problems students have with takeoffs as well as some solutions and helpful suggestions.
Students frequently tend to apply takeoff power either too quickly or too slowly. They figure that an aircraft engine is just like the computer-controlled, fuel-injected marvel in their car, and they gun it when they are cleared for takeoff. Unfortunately, the reality is that most training aircraft carburetors and fuel injection systems are extremely old designs. They can't handle "pedal to the metal" acceleration. The power must be applied gradually enough that the engine doesn't cough or hesitate. A good rule of thumb is to advance the throttle from idle to full power in about two to four seconds.
Another common problem students may have is maintaining directional control while on the takeoff roll. Invariably the aircraft starts off on the centerline but then drifts slowly toward the left or right side of the runway. Sometimes the aircraft swerves as you try to get it back toward the centerline.
First, your student must be able to discern where the nosewheel is in relation to the centerline. This takes some practice in most side-by-side trainers, because you're not sitting on the centerline of the aircraft. To recognize this difference, have the student lean over the center of the aircraft as you're taxiing. He'll probably see a whole new perspective. Help him by calling out how far you think the nosewheel is from the yellow taxi line. That might help the student to make adjustments appropriately.
Don't accept substandard performance while taxiing. Discipline your students to always taxi at a safe speed and on centerline. Remember, if you accept sloppiness during taxi, you are asking for directional control problems at the higher takeoff and landing speeds.
Watch for overcontrol of the rudder pedals on the takeoff run. Because a takeoff involves high speeds, it is normal to feel a "rush" during the takeoff run. Everything seems to be happening at once. This sense of urgency can cause overcontrolling of the rudder pedals. The student should try to relax and realize that as the aircraft gathers speed, progressively smaller rudder pedal inputs will be required to keep the aircraft tracking the centerline. If the aircraft gets off the centerline on a wide runway, don¿t insist that he steer back toward it. At the high speeds of the takeoff run this can be unsafe. Instead, concentrate on just paralleling the centerline from your current lateral position. This will result in a safer and smoother takeoff run.
Another common problem with maintaining directional control is that students don't look far enough ahead of the aircraft. Specifically, at higher speeds, your vision must be focused farther down the runway in order to have time to react. If you find your student reacting to the aircraft rather than controlling it, he is probably not looking far enough ahead and his rudder corrections are too late. Try focusing anywhere from 20 to 100 yards in front of the aircraft (depending on speed) so that smooth, timely corrections can be made.
Sometimes high-speed taxi practice is helpful. Ask the tower controller for a high-speed taxi, or at a nontowered airport, ensure the runway is clear. Accelerate the airplane to just below rotation speed while tracking the centerline. Hold this speed as long as practical, let the student practice making timely rudder corrections, and plan your deceleration to leave ample runway remaining.
Another element many students have problems with is rotation. They either rotate too early or too late, and/or they over- or under-rotate. A proper rotation is important for safety reasons and minimizing takeoff distance. For example, rotate too early and drag increases, increasing the takeoff distance. Rotate too late and the airplane could skitter down the runway with the nosewheel on terra firma and the main gear in the air, in a condition commonly called wheelbarrowing.
A proper rotation is easy if you keep in mind these simple points. First, when you line up on the runway, verify that your pitch trim is set to the takeoff position. Second, you must know the published rotation speed for your aircraft. To help build airspeed awareness on the takeoff run, you should make it a habit to call out "airspeed alive" when the airspeed indicator needle moves off its peg, and "rotate" when rotation speed is reached.
The student must be able to recognize what the target pitch attitude looks like from the cockpit. One description is to raise the pitch attitude until the front cowling appears to cover up the runway ahead. Another is to raise the end of the cowling to the horizon. Your demonstration can be worth a thousand words here. Each combination of aircraft and student will result in a slightly different picture. However, once this picture or "snapshot" is established, the nose should be rotated into that position on every takeoff. Once the aircraft is rotated and placed into the takeoff attitude, the student should hold that attitude until the aircraft reaches flying speed and lifts off the runway by itself, usually a few knots above rotation speed. A common misconception many students have is that rotation means liftoff. In most cases this is not true for small general aviation trainers. So, when the aircraft doesn't lift off when they rotate, they continue applying backpressure until it does. This results in overrotation.
Probably the most frustrating and by far the most challenging problem for all students is maintaining a proper ground track during climbout. And that ground track is important. A straight upwind is crucial for traffic separation at airports with simultaneous departures off parallel runways.
Students have trouble determining their aircraft's ground track during the climb, because their normal visual references are obscured by the nose. If there is not much crosswind, just keeping the wings level will maintain a fairly straight upwind track. Since the horizon is obscured by the nose-high attitude, you'll have to use your peripheral vision to keep zero bank. If you still can't see well, then by all means use your attitude indicator to maintain wings level.
Another good method is to use the heading indicator to maintain the runway heading. But remember, heading only equals track in a no-wind condition. Therefore, frequent glances behind the aircraft allow you to see if you are maintaining the desired ground track. If not, the heading must be adjusted left or right to correct for wind drift. In order for this method to work well, the pilot must hold heading very closely by keeping the wings level. Also, make sure your student is holding enough right rudder pressure to compensate for p-factor. Relaxing this pressure can cause drift to the left.
The normal takeoff is a reasonably simple maneuver, but it involves more elements and details than most students and instructors realize. Don't let your student become discouraged. Sometimes there are no easy solutions. Good takeoffs require an ounce of knowledge, a pound of skill, and tons of practice, patience, and perseverance.
Christopher L. Parker is a CFI and an aviation author, speaker, and FAA remedial training specialist. He is captain of a Canadair Challenger for a private operator based in Ontario, California.
More takeoff help
A new AOPA Air Safety Foundation safety seminar, "The Ups and Downs of Takeoffs and Landings," is now touring the country. With real-life video of hapless pilots attempting to get it right, this seminar is must-see education for any pilot. All ASF seminars are open to all pilots without charge. A schedule of ASF seminars
is on page 13 of this issue, and a short streaming video clip from "Ups and Downs" is available online.
By Christopher L. Parker