Training Tip: A slipping scenario

About a mile from the threshold, descending, the student pilot senses that the aircraft is too high. After verifying that the airspeed is within the white arc, he extends partial flaps in two quick applications, planning to hold off on using full flaps until very short final.

Unfortunately, the headwind component is stronger than the student anticipated. Now he faces a dilemma, and must increase engine power to keep the descent rate manageable. (He already knows from some pre-solo learning experiences that retracting the flaps would be a bad idea; likely destabilizing sink rate and airspeed control at a critically low altitude. Raising the nose to try to “stretch the glide” would be even worse.)

Was there a better way to fly the approach?

Indeed there was. This is the kind of scenario that is tailor-made for using a forward slip (see Area of Operation IV, Task M, Private Pilot—Airplane Airman Certification Standards) to get onto the proper glide path. Then, when stability has been restored, he could discontinue the slip and reconfigure with flaps as desired to complete the landing.

The forward slip works by inducing drag via the judicious, intentional crossing of the controls.

“A forward slip is one in which the airplane’s direction of motion continues the same as before the slip was begun. Assuming the airplane is originally in straight flight, the wing on the side toward which the slip is to be made should be lowered by use of the ailerons. Simultaneously, the airplane’s nose must be yawed in the opposite direction by applying opposite rudder so that the airplane’s longitudinal axis is at an angle to its original flightpath,” according to a description of the maneuver on page 8-10 of the Airplane Flying Handbook.

Note that this is a different maneuver, with a different intent, than a sideslip—although it is possible to combine the two if conditions warrant. Also, be aware of potential airspeed errors when performing a forward slip.

With practice, the maneuver will give you a reliable resource for controlling the glide path, or for losing altitude without increasing airspeed or extending flaps during a simulated (or real) emergency landing.