Complex sentence: The director of the aerospace department at the Deutsches Museum stated that such a replica was not proof that the original did actually fly, in that the 1998 reproduction used modern research and materials such as fibreglass, and had a modern engine.
Split into simpler sentences: The director of the aerospace department at the Deutsches Museum stated that such a replica was not proof that the original did actually fly. The 1998 reproduction used modern research and materials such as fibreglass, and had a modern engine.