NASA tasked LMI to assess the potential contributions of a yet-undeveloped Civil Tiltrotor aircraft (CTR) in improving capacity in the National Airspace System in all weather conditions. The CTRs studied have assumed operating parameters beyond current CTR capabilities. LMI analyzed CTRs three ways: in fast-time terminal area modeling simulations of New York and Washington to determine delay and throughput impacts; in the Integrated Noise Model, to determine local environmental impact; and with an economic model, to determine the price viability of a CTR. The fast-time models encompassed a 250 nmi range and included traffic interactions from local airports. Both the fast-time simulation and the noise model assessed impacts from traffic levels projected for 1999, 2007, and 2017. Results: CTRs can reduce terminal area delays due to concrete congestion in all time frames. The maximum effect, the ratio of CTRs to jets and turboprop aircraft at a subject airport should be optimized. The economic model considered US traffic only and forecasted CTR sales beginning in 2010.Stouffer, Virginia and Johnson, Jesse and Gribko, Joana and Yackovetsky, Robert (Technical Monitor)Langley Research CenterFEASIBILITY ANALYSIS; ECONOMICS; ENVIRONMENTAL SURVEYS; MODELS; TILT ROTOR AIRCRAFT; TURBOPROP AIRCRAFT; NATIONAL AIRSPACE SYSTEM; AIRPORTS; CONCRETES; CONGESTION; SIMULATION; TRAFFIC; VIABILITY; WEATHER