Lufthansa Technik has ordered an electric aircraft tug that can handle widebodies as large as the Airbus A380.
Swedish manufacturer Kalmar Motor has designed the hybrid-powered, towbar-less tractor, but no vehicle has yet been produced.
LHT’s ground support subsidiary, Lufthansa Engineering and Operational Services (LEOS), has now signed a contract for a prototype, which is to be delivered to parent carrier's Frankfurt hub in late 2014. That will be the industry’s first hybrid tractor for widebodies, says Kalmar.
With the launching deal, the MRO group is taking part in the tractor’s specification, particularly for the design of the lift mechanism for the aircraft’s nose wheels, says Gerhard Baumgarten, marketing and sales director at LEOS.
The tug will be equipped with a small diesel engine to generate energy for the electric motors on all main wheels and the lifting mechanism. However, the combustion engine is only to be used as a safety fall-back option, when the vehicle’s lithium-ion batteries fail.
The main power source will be the batteries, which are to be charged through the general electricity grid. A charge should supply enough energy to operate the tug – which is to be capable of towing widebodies weighing up to 600t – for eight hours, says Kalmar.
However, electric capacity is one of the key areas that LEOS wants to assess during a six-month trial. The batteries alone might not supply sufficient energy for a full shift, says Baumgarten, because the tractor will be used to tow A380s with a near-full fuel load.
To reduce downtime at the airport gate, Lufthansa is putting most of the fuel on board at its A380 hangar on the southern side of Frankfurt airport, which means towing distances to the terminal of up to 7km, he says.
However, the tractor’s electric motors will also act as generators to convert kinetic energy into electric energy for the batteries when the tractor slows down during towing manoeuvres.
If the trial is successful, LEOS plans to order a second tractor.
The introduction of the hybrid vehicle is part of Frankfurt's “Airport eMove” environmental initiative, which is funded by Germany’s transport ministry.