Expert: Marc Ebelini - 2/4/2011

Question
Marc,I know that in air the plane moves left/right by its rudder and wings but i want to know that when the plane is on land how does it turns left/right.The joystick in the plane is for moving the wings not the tyres so,what thing turns the tyres of the plane.

Answer
There are two main types of aircraft landing gear, tricycle and what are called tail draggers. The tricycle system is the common type used today where airplane has a nose wheel. In light aircraft the nose wheel is control buy the rudder pedals so that steering is accomplished with the pilots feet. In commercial aircraft the nose wheel is hydraulically controlled with a small steering wheel on the left side of the captains station. Tail draggers or tail wheel airplanes have a small wheel at the tail below the rudder. Here to there are two methods of control. Some are controlled by rudder pedals that are linked to the tail wheel with springs to absorb any shock. Older airplanes simply used the brakes attached to the rudder pedals so that braking one wheel would cause the tail wheel to pivot turning the plane in the direction of the braked wheel.
Some airplanes had tail wheel locks to keep the tail wheel straight while taxing in strong crosswinds. This was possible because as I mentioned previously the rudder pedals were linked to the tail with springs. This allowed the rudder pedals to move without moving the tail wheel when locked. May I add that while the airplane is controlled as stated on the ground the control wheel or joy stick plays an important part too. Some examples; While taxing a tail dragger in a strong tailwind the control must be forward to keep the elevator in a nose down condition. If the elevator is in the nose up position the wind could lift the tail up and nose the plane over. The ailerons too must be positioned properly. Example; In a tricycle plane taxing with a strong tailwind. If the wind is coming from the starboard side then the aileron on that side should be down so that the wind cannot get under it and lift the ring wing and flip it over. Of course this applies mostly to light aircraft. Using a model airplane can help visualize this. Taxing a light aircraft in strong winds is not like driving a car under the same conditions.