What is the primary purpose of using pushback vehicles?

The primary purpose of using pushback vehicles is to ensure a safe departure from the gate. These vehicles are designed to push an aircraft away from its parking position without requiring the aircraft's engines to be operated during this initial phase. This is especially important for safety, as it helps prevent potential collisions with ground equipment or other aircraft in the congested airport environment. Additionally, pushback vehicles provide precise control of the aircraft's position as it begins to taxi, allowing ground personnel to manage the movement efficiently and safely.

While other options involve important functions within airport operations, they do not align with the specific role of pushback vehicles. Cleaning the ramp area, assisting passengers boarding, and providing maintenance support are all critical activities at the airport but are performed by different teams and equipment. Thus, pushback vehicles are fundamentally geared towards facilitating a secure and orderly departure from the gate.