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The report summarizes wind tunnel studies of flapping wings of locusts and several artificial wings. The stroke-averaged lift and horizontal force are measured in a wind tunnel at an angle of attack varying from horizontal to hovering positions. It is found that for high angles of attack, flapping wings do not exhibit the typical abrupt stall seen with fixed wings. Based on high-speed video data, a theoretical analysis of the flapping wings is performed using the discrete vortex method. It is found that the inertial component is dominant in the normal force coefficient in the studied problem. A normal component of the acceleration of the wing's trailing edge is introduced as a kinematic parameter. The report also focuses on transition performance of fixed-wing aircraft with vertical takeoff and landing capabilities. Obtained results show that rapid-pitching efficiency curves converge on steady efficiency curves. From 30 to 70 degrees, efficiency is virtually independent of pitching-rate, throttle-setting, and elevator deflection.