The fuel consumption of aircraft engines has been greatly reduced over the years, but jet turbines still burn large quantities of kerosene. For example, the four engines of an Airbus A380 lift almost 600 tons in the air and drive it at over 1,000 km/h. Aircraft on the ground are completely overpowered, which means that an aircraft at the Frankfurt airport will use 600 liters of kerosene simply to move to take-off position.
Engineers at Lufthansa Engineering and Operational Services GmbH (LEOS) are working on methods of reducing this waste of fuel – it also involves a lot of noise. The very interesting series of “engineering stories” published by the VDI reports how Gerhard Baumgarten, manager of the innovation department at LEOS, and his team have developed an electrically powered vehicle to solve this problem.
An interesting fact is that the major problem when towing an aircraft is not moving it but braking it. The larger the aircraft the more difficult it is to brake the heavy weight if the only point of contact is the nose wheel. Taxibot uses a different method. The pilot controls the aircraft and the taxibot. The nose wheel is placed on a turntable, which transfers the pilot’s steering movements to the taxibot. When the pilot applies the brake all brakes of the taxibot are used. At the take-off runway the taxibot is disconnected, the pilot starts the engines and takes off. A driver then drives the taxibot back to the terminal – or docks with an aircraft that has just landed and tows it to the terminal. The taxibot has been in regular use at Frankfurt with 737 aircraft since February 2015. It is expected to save 2700 tons of kerosene a year.
Dipl.-Ing. Ralf Steck