42 Technical computer project management, technical computer hardware development, technical consultancy in the field of design and development of computer hardware and software for use on aircraft, and engineering, also for others, in the field of in-flight multi-media systems, in-flight television systems, in-flight sound systems, in-flight loudspeaker systems, in-flight audiovisual systems, in-flight audiovisual apparatus, in-flight cabin management systems, in-flight controllers, in-flight communication systems, in flight computer hardware systems, in-flight testing equipment, in-flight entertainment systems comprising a computer, multiple input devices, printer, loudspeaker, sound systems, video systems, in-flight television systems comprising TV, beamers, multiple image display screens, multiple input devices, in-flight sound system comprising loudspeakers, sound bars, subwoofers, microphones, controllers, in-flight light systems, in-flight heat systems, systems and apparatus for lighting, heating, cooking, refrigerating, drying, ventilating, water supply and sanitary purposes, in particular for using and fitting out aircraft interiors