What is the primary purpose of a tug vehicle in aviation?

The primary purpose of a tug vehicle in aviation is to push the aircraft away from the gate. Tugs are designed to maneuver aircraft on the ground, especially during pushback from the terminal. By connecting to the aircraft's nose gear, tugs can either push the aircraft backward or tow it to different locations on the tarmac. This process is crucial for safely repositioning aircraft before takeoff or after landing, as it allows for efficient ground operations without the need for the aircraft to use its own engine power, which is more efficient and helps minimize ground congestion.

In contrast, options related to increasing flight speed, assisting in flight navigation, or transporting luggage address different functions that do not fall under the operation of tug vehicles. Flight speed pertains to the aircraft’s performance in the air, navigation is managed by pilots with the help of onboard systems, and luggage transportation is handled by ground crews using different vehicles designed for that specific purpose.