What is the main purpose of landing gear in an aircraft?

The main purpose of landing gear in an aircraft is to support the aircraft while it is on the ground. This includes bearing the weight of the aircraft during various ground operations such as taxiing, takeoff, and landing. The landing gear allows for safe landings by absorbing the stresses and forces experienced when the aircraft touches down. It also provides stability while the aircraft is stationary or moving on the ground, ensuring that it remains level and balanced.

While stabilizing the aircraft in flight and assisting in maneuvering on the flight deck are important considerations for an aircraft's overall design and operation, they do not directly relate to the primary function of landing gear. Additionally, landing gear does not provide a mounting point for engines, as engines are typically mounted on the wings or fuselage. Thus, the correct answer accurately reflects the essential role of landing gear in supporting the aircraft when it is not in the air.