This paper investigates the influence of the integration of Life Cycle Assessment (LCA) on conceptual aircraft design. The Environmental Impact (EI) of different life cycle phases and the driving design parameters of the EI of an aircraft are analyzed. A trade-off between low EI and low Direct Operating Costs (DOC) is investigated. It is shown that while DOC and EI optimized aircraft differed a lot in the past when Airbus A320 had its entry into service, they have nowadays become more similar due to a strong surge of fuel price making low fuel consumption a key design criterion also for DOC. It is shown that in 2030, a next generation turboprop driven medium range aircraft, solely optimized for minimum EI, could have the potential of improving EI by about 46 % while still improving DOC by about 12 % compared to nowadays medium range aircraft.