Airplane wheels, also known as landing gear, are the hardest-working equipment on any airplane. They bear the full weight of a passenger aircraft, its cargo, and passengers; endure extreme heat and stress; and are subject to sudden spin-ups during takeoff, aggressive stops at high velocities, and constant contact with runway surfaces. Airplane wheels must be able to handle all of this while being designed to distribute the weight evenly across the landing gear assembly and avoid damage to the runway surface.
To the casual observer, commercial airliners seem to have a standard tire configuration: two wheels in the nose and two under each wing. This arrangement can be seen on planes ranging from the turboprop Saab 340 to the Boeing 777 and beyond. But this isn’t the only way for manufacturers to arrange airplane wheels. In fact, the number of tires on a given plane can vary significantly from one model to the next.
The number of airplane wheels depends on the size and purpose of an airplane, with smaller private aircraft generally having fewer than larger corporate or military planes. The biggest commercial airliners and most cargo jets have between two and eight wheels in the main landing gear. Military and private planes usually have three to five wheels, with the number of wheels in a specific aircraft often being proportional to its weight and intended use.