An innovative hybrid system will let aircraft move on the tarmac under electric power instead of using their main engines.
The electric green taxiing system (EGTS) was developed by EGTS International, a joint venture between Honeywell and Safran, and debuted at The Paris Air Show.
The system uses the auxiliary power unit (APU) generator to power electric motors in the main landing gear. Each of the aircraft’s powered wheels is fitted with a control system, giving pilots total control of speed and direction during taxi operations.
The system has the potential to reduce fuel consumption by up to 4 per cent on a short-haul flight. Aside from the financial benefits, there are environmental advantages with reduced carbon and nitrogen oxide (NOx) emissions during taxi operations as well as lower noise levels, an important consideration at urban airports.
Much as a hybrid car uses electrical power at low speeds, the technology enables aircraft to avoid using their main engines during taxiing and instead move autonomously under their own electrical power.
Because an aircraft’s main engines are optimised for flying rather than taxiing, they burn a disproportionate amount of fuel during ground operations. With a short- or medium-range aircraft spending up to two and a half hours on taxiways every day, EGTS could save approximately 600kg of fuel used during taxiing per day, according to Honeywell and Safran.
“EGTS is a revolutionary system that brings immediate benefits for a pilot operating in congested airports,” Safran test pilot Jens Berlinson explained. “In addition to faster push-back times, being fully autonomous with its reverse mode, the system is very smooth and so easy to operate, enabling the plane to accelerate without any delay, and move at a steady rate.
“With EGTS we no longer need to use the brakes, unlike with today’s aircraft that have a tendency to accelerate naturally even when the engines are at idle. This is especially valuable in busy airports, where planes are often queuing up for an extended period of time before take-off.”