An aircraft tug is a ground vehicle that moves aircraft around an airport surface such as an apron or taxiway. Tugs have an internal power source (commonly an internal combustion engine or a battery-powered electric motor) which is used to propel both vehicles when under tow. They may be driven by humans or remotely operated, and are manufactured in a wide range of sizes depending on the mass and type of aircraft they are intended to handle.
Design
editTugs are built in a wide range of sizes and types, reflecting of the extreme variety of aircraft they are made to handle. Small aircraft (like many reciprocating engine-powered general aviation airplanes) are commonly manipulated with manual hand-tools called towbars, though powered variants are also common. Mid-sized airplanes are often paired with tractor-style utility vehicles, and larger transport category aircraft such as airliners and cargo jets may be handled with large, purpose-built "super-tugs."
Interface
editOne of the most significant design elements of a tug is its method of attachment to an aircraft's landing gear, which itself is generally classified in two configurations: tailwheel or tricycle landing gear. Attachment is commonly achieved by a towbar linking the tug's hitch with an attachment lug on the landing gear, or by simply lifting one or more landing gear off the ground entirely.