This report includes three experiment sections. The first experiment tested sensitivity to loss in altitude and demonstrated that: (1) preview effects led to adaptation; (2) sensitivity decreased with higher flow rates; and (3) sensitivity increased with higher optical texture densities and fractional loss. The second and third experiments examined the perception and control of change in forward speed and altitude, respectively. Results from the former indicated that higher levels of fractional loss led to enhanced control of a constant speed, whereas high flow and/or edge rates interfered with performance. The control of altitude change was similarly affected by the levels of fractional loss, but the negative effect of flow rate occurred only in conditions of descending flight. Theoretical implications for the ecological approach to the study of perception and control are discussed. (Author)