Immediately after a plane lands, passengers disembark, and luggage is removed, a small tractor moves on the runway, ready to tow it away.
That special vehicle is an aircraft pushback tractor, towing tractor or airport tractor. The powerful vehicle is characterised by a low-profile design and large wheels to move an aeroplane between different locations.
A pushback tractor is essential in aviation as most aeroplanes cannot reverse themselves from the aircraft stand.
A towing hook similar to that used in vehicles is attached to the plane, and then the driver of the tractor receives a signal from the pilot before the pushback operations begin.
The tractor then pushes a plane back and steers it in the correct position on the taxiway, a pathway between the aircraft stand and the runway.
After fixing it in its correct position, the pilot issues a disengaging signal to unhook the towing bar from the plane.
Why a Plane Cannot Reverse Itself
Most planes cannot reverse themselves due to a lack of reverse thrust mechanisms.
According to Aviation Learnings, a US academic programme, aircraft engines produce thrust by expelling high-temperature and high-velocity air behind them.
The high-velocity air allows a plane to move forward. It operates on Newton's law of action and reaction(for every action force in nature, there is an equal and opposite reaction).
With airport architectural designs, allowing a plane to reverse would destroy airport buildings and other facilities, such as the passenger boarding bridge, due to the reverse thrust.
Due to this reason, an aircraft cannot reverse itself and thus requires an aircraft pushback tractor to push it back from the bay.
Taxibot
To enhance the towing process, an Israeli firm developed a semi-robotic tug called a TaxiBot. It performs a similar function to a pushback tractor but more efficiently and faster.
"Rather than push the aircraft back from the gate, the TaxiBot transports the plane from the gate to the runway (taxi-out phase). After landing (taxi-in phase), the TaxiBot meets the aircraft as it departs the runway and takes it to the gate," Simply Flying, an aviation magazine indicated.
