In the last thirty years aircraft performance has experienced diminishing returns in terms of efficiency, on the order of 1% reduction in fuel consumption annually since 2010. Meanwhile, according to projections by Airbus and Boeing, air passenger traffic is expected to increase 3.5-4.6% per annum. ICAO has recommended that overall energy efficiency be improved by 2% annually. The rate of increase in demand and decrease in fuel consumption, raises the question of how this goal can be met.In this paper, engine technology advances are identified as the most significant contributing trend to aircraft performance. These trends are extrapolated in order to analyze the conditions that could lead to a potential break in the dominant aircraft architecture. A hybrid analytical-empirical model for aircraft optimization is used to predict the effects of these technological trends on aircraft design. Four technology scenarios are used to analyze the expected performance increase and expected year of break in architecture, for existing airframes and unconstrained airframe geometry.It is found that for existing airframes performance is expected to increase by 6-38% * Graduate Student Researcher, System Architecture Lab, Room 33-409, Massachusetts Institute of Technology,