What supports the plane's weight when it is on the ground?

The main landing gear is specifically designed to support the weight of the aircraft when it is on the ground. This system consists of wheels, struts, and supporting structures that distribute the aircraft's weight uniformly, allowing for safe ground operations such as taxiing, takeoff, and landing. The main landing gear must be robust enough to withstand the significant forces experienced during these operations, ensuring the aircraft's stability and integrity while stationary.

The other components mentioned have different functions. Flight spoilers are primarily used to reduce lift and increase drag during descent and landing, contributing to better control and stopping distances rather than supporting weight. Leading edge slats are designed to improve aerodynamic performance by increasing lift at lower speeds, particularly during takeoff and landing phases, and do not participate in weight support. Trim tabs are control surfaces that assist in stabilizing the aircraft in flight and are not involved in supporting the aircraft on the ground.