Honeywell and Safran have commenced the first rolling tests for their electric green taxiing system. The electric green taxiing system is designed to significantly improve airline operational efficiency and provide environmental benefits by slashing the carbon and other emissions created during runway taxi operations. Using the Auxiliary Power Unit (APU) generator to power motors in the main wheels, the system allows aircraft to taxi without requiring the use of aircraft engines. Each of the aircraft’s powered wheels is equipped with an electromechanical actuator, while unique power electronics and system controllers give pilots total control of the aircraft’s speed, direction and braking during taxi operations. This first set of tests, run in Montpellier, will take place on an A320 and will serve to evaluate runway conditions and calculate the necessary loads needed for moving the aircraft on the ground.
The expected benefits of this system include:
• Lower Fuel Burn – As taxi operations burn a significant amount of fuel—as much as five million tons of fuel per year for short-haul aircraft—the electric green taxiing system can result in savings of up to 4% of total block fuel consumption.
• Improved On Time Performance – Aircraft equipped with the system will be able to “pushback and go” more quickly, thus reducing both gate and tarmac congestion, improving on-time departure performance and saving valuable time on the ground.
• Greener Operation – The electric green taxiing system greatly reduces engine emissions, resulting in lower carbon taxes.
• Added Value – System operation eliminates the need for aircraft pushback and aircraft repositioning via tug tractor while also reducing brake wear, extending main engine life, enhancing ground crew safety, and reducing noise in the airport environment.
The initiative was first announced at the Paris Airshow in June 2011, where Honeywell and Safran signed a memorandum of understanding to create a joint venture company to deliver innovative new electric green taxiing system solutions for new and existing aircraft.
Yves Leclère, Safran Executive Vice President, Transformation said, “Safran’s extensive experience in integrated landing gear systems combined with Honeywell’s avionics and APU breadth is an ideal match for rapidly bringing to market an innovative solution which makes business and environmental sense for both airlines and airports.”
This initial series of tests, to be undertaken in Montpellier, France, on a recently acquired A320, will serve to evaluate runway conditions and calculate the necessary loads needed for moving the aircraft on ground. The team is currently focused on prototyping and component level testing, prior to targeted system installation and ground testing in 2013.
“Reducing fuel costs and maximizing operational efficiency are top priorities for our customers”, said John Bolton, President, Honeywell’s Air Transport and Regional business. “The start of the electric green taxi testing takes us one step closer to bringing this technology to market, and ultimately to helping to save our customers several hundred thousand dollars per aircraft per year.”
The system is particularly attractive for airlines that operate high cycle single aisle aircraft. Honeywell and Safran are targeting to offer the electric green taxiing system either on new aircraft or as a retrofit solution to in-service aircraft as early as 2016.
Wheel tug has a wide open window as yet, but better not dawdle.
This one needs two motors. "Off the shelf parts" Probable cheaper than Wheel Tug. OTOH it is probably heavier reducing efficiency and extra weight for the aircraft to fly with and a bit extra fuel. Reducing savings.
It requires the removal of some of the brakes as well. This is not the production model and it will change some. I found on a pilot forum someone who was not happy with that prospect.
It seems both of the other companies have motors on both sides.
Wheel Tug's motors will be integrated into both NLG wheels with a total equipment weight of 300lb (136kg), including cockpit interface and system-control unit.
The Safran/Honeywell is 200kg or 440lbs for the part in the wheel alone. Each wheel actuator, which includes the motor, gearbox and clutch to disengage the system for take-off and landing, should weigh no more than 100kg, according to Savin.
(Probably approaching double Wheel Tug's 300 lb weight) There are no specific weights for L-3 (I would guess it the same as The Safran/Honeywell at 200kg or 440lbs, just a guess mind you.)