Complex sentence: The aircraft was moved temporarily to the museum's storage facility at Chicago's O'Hare International Airport, but before the museum could arrange to ferry the aircraft to Washington D.C. the National Advisory Committee for Aeronautics asked to borrow it.
Split into simpler sentences: The aircraft was moved temporarily to the museum's storage facility at Chicago's O'Hare International Airport. Before the museum could arrange to ferry the aircraft to Washington D.C. the National Advisory Committee for Aeronautics asked to borrow it.