To summarize, there are four control measures that can be used to control the airplane on the ground. They are rudder, brakes, ailerons, and throttle.
During the after landing roll, the pilot can maintain directional control by using varying degrees of rudder, brake, and/or throttle. Whether they are used in any sequence, or all simultaneously, depends on the nature of the landing problem. It is very important that control be maintained through the landing roll. If the airplane turns excessively the pilot should not try to realign it with the runway immediately. Instead it should be held straight until the airplane is under full control, then it should be gradually realigned with the runway. A number of accidents occur because the pilot over controls while attempting to realign the airplane. Keep the wings level by maintaining direction and using the ailerons.
If the airplane has attained a landing attitude and is still well above the ground, a stall or rapid rate of sink must not be allowed to develop. Add power, or EXECUTE A GO-AROUND and plan another approach.
Any time the airplane approaches a stalling condition, whether after ballooning or contacting the ground and bouncing, apply full power, adjust the pitch attitude, and go around. It is unsafe to continue the landing.
During the after landing roll, if a wing starts down, use aileron to raise it and, if necessary, use throttle to increase its effectiveness. Note that as the forward speed of the aircraft decreases, the ailerons become less effective.
Throttle increases both the thrust and lift of the airplane by increasing the relative wind over the wings and the slipstream over the tail surfaces. This causes these surfaces to be more sensitive and effective. During turns or swerves, adding throttle will pull the airplane forward and resist the turning of the airplane, but it will also increase torque. When large amounts of throttle are used, torque must be anticipated and corrected. As a safety rule remember, if used in time, the throttle will get the pilot out of almost any difficulty.