The paper discusses the USRA/Raytheon E-Systems approach for designing and building the Stratospheric Observatory For Infrared Astronomy (SOFIA) aircraft. A Boeing 747SP aircraft will be refurbished and modified to house a 2.5 meter telescope designed to make sensitive infrared measurements of a wide range of astronomical objects. USRA/Raytheon's design approach employees state-of-the-art design and analytical tools as well as flight and ground testing to ensure a safe and certifiable SOFIA aircraft.