Airport Pushback Tractor

Overview

An aircraft pushback tractor is a ground-support vehicle whose single job is to move a parked airliner that cannot reverse under its own power. Because jet engines provide no reverse thrust on the ground, the aircraft is pushed back from the gate by a tractor coupled to its nose landing gear. Two things distinguish the machine: it is extremely low, so it fits under a fuselage and presents a small profile against the aircraft, and it is heavily ballasted, because pushing a fully loaded widebody demands enough mass and tyre grip to avoid simply spinning its wheels. Conventional tractors connect through a towbar; towbarless designs scoop the nose-gear tyres into a cradle and lift them, putting that weight onto the tractor for even more traction.

How it works

The machine is built around a Low Chassis, a low and very heavy welded frame. A turbocharged Diesel Engine drives a Hydrostatic Drive of the hydrostatic type: an engine-driven variable pump feeds hydraulic motors at the axles, so the operator gets full torque from a standstill and fine creep control when nudging a multi-hundred-tonne aircraft. Each heavy Heavy Axle carries the load through a final-drive differential, and bolt-on Ballast weights add the mass that turns engine torque into push without wheelspin.

The aircraft interface is the Coupling Hitch: a towbar coupling for conventional work, or a powered cradle that clamps and lifts the nose-gear wheels for towbarless pushbacks. Those motions, along with steering, come from the Hydraulic System power pack and its valve block. The Brakes hold the tractor firmly against the aircraft's load, and the operator works from a low, fully glazed Cab with sight lines to the gear and wingtips. A 24 V Electrical System system runs the beacons, controls, and lighting that apron operation requires.