The paper summarizes preliminary results from a research program undertaken to develop aerodynamic technology for VSTOL fighter/attack aircraft projected for the post-1990 period. This program features industry studies jointly sponsored by NASA and the Navy. General Dynamics and Northrop provided four conceptual designs, identified aerodynamic uncertainties for these concepts, and built wind-tunnel models. Tests are being conducted in the Unitary and 12-Foot Wind Tunnels (M = 0.2 to 2.5) at Ames Research Center to investigate the uncertainties and to develop an aerodynamic data base for these types of configurations. Experimental results from this program are presented together with predictions by Ames and contractor participants. A description of a research effort to investigate airframe effects on top-mounted inlets is also provided.