In collaboration with twelve students from Glasgow School of Art, 25 scientists from Bauhaus Luftfahrt have developed a well-matched airport and aircraft concept: “CentAirStation” and “CityBird”. Their mission statement: New inner-city airports and new aircraft operating regionally between these new inner-city airports and conventional airports will contribute greatly to solve major air transport challenges in 2040 and beyond. Four key drivers set the scene for Bauhaus Luftfahrt’s group design project on future transport concepts:
- Urbanisation already is an important trend to today’s transport challenges but will become even more important up to 2040 and beyond.
- Various air traffic forecasts predict global growth rates to be around 4.7 % per year, indicating big challenges of tripling air traffic by 2040.
- Population development and urbanisation lead to a fast growing number of megacities of more than ten million people. Connecting airports efficiently with these megacities is a major challenge.
- Amongst other goals of Flightpath 2050, the European Commission envisages four hours door-to-door for 90 % of all travellers.
However, this goal cannot be achieved without a new and holistic transport concept.
For the quantification of possible locations of CentAirStations in a city and their worldwide potential, Bauhaus Luftfahrt investigated available urban brown spaces, which are only used by rail tracks. These spaces were identified and measured based on publicly accessible geographic information. The analysis was performed to calculate the number of possible locations as well as their maximum lengths and widths. The evaluation of the most populous cities in the US, Europe and Asia showed that rail tracks for future CentAirStations would be available in almost 100 cities on all continents. From the analysis of possible locations in the US, Europe and Asia, also top-level design requirements for the CentAirStation airport concept were derived: a maximum runway and building length of 650 m as well as a maximum runway and building width of 90 m.
The concept of CentAirStations aims at significantly increasing the capacity of the air transport system by existing and future city pairs being shifted from conventional airports to CentAirStations. Today’s seating capacity between cities in the US, Europe and Asia as well as the number of possible locations per city set the maximum passenger capacity of CentAirStation with 10.5 million travellers per year. As a result, in the US the total capacity could be increased by an average of 185 %, in Europe by an average of 480 % and in Asia by an average of 341 %.
The CentAirStation building with a length of 640 m and a width of 90 m consists of at least four levels: 1) On the rail level, passengers arrive to the CentAirStation by suburban railway or with high-speed trains. Each platform is connected by escalators and lifts to the overlying public level. 2) The public level includes both fully accessible facilities and areas for aviation-specific processes such as the vetting of passengers. 3) The apron level can accommodate a total of 15 gate positions for ground handling of CityBirds including all components of required equipment and connections. 4) On the runway level, many features are available, which enable an efficient and safe operation of CityBirds in the smallest space. The predominantly vertical passenger routes through the CentAirStation building allow very short processing times: Departing passengers will need only 15 minutes from arrival at the airport through to take-off of the aircraft. Arriving passengers will be able to exit the building just ten minutes after they got out of the aircraft in the gate position.
The CityBird has been specially designed as an aircraft for inner-city operation. The high population density in cities and the limited available space put high requirements on noise protection, safety and short take-off and landing capability (STOL) of the aircraft. Furthermore, the aircraft must be efficient and fast enough to achieve the goal of four hours door-to-door over the required range. Operation on conventional airports without affecting the running processes is provided. The long list of specifications poses major challenges for aircraft design that are addressed, among others, through the use of new technologies: a low wing configuration with aft-mounted engines, a small and faired landing gear as well as a simple high-lift system along the entire span of the wing.