Reading list: To land in an emergency, or on to a field with obstructions, there is a maneuvering technique that allows a sharp descent angle without an increase in airspeed: a slip. (Note that the AFH says, "A pilot should not use a slip to lose altitude because of poor planning" p. 7-8) There are two kinds of slip: a forward slip, and a sideslip. We use sideslips normally counter the wind during a crosswind landing, putting one main wheel down before the other. The forward slip looks different, as you will see.