Z is altitude, X and Y are lateral displacements, and ‘Angle’ is the projection of the vehicle’s orientation onto the X–Z plane (that is, the camera view), with vertical being zero. The light turns on at t = 0, and the vertical dashed line indicates when it has reached full intensity. a, The flight shown in Supplementary Video 9 (the lowest-power flight). b, The flight shown in Supplementary Video 4. Depth (Y) is estimated by measuring the fractional change in the peak width of the flexboard as our integrated vehicle spins about the yaw axis (that is, twice every yaw period, we measure the width of the flexboard), along with the starting distance from the vehicle to the camera (approximately 90 cm). The error bars on Y are due to the pixel resolution error (±0.2 mm) amplified by the ratio of the camera distance to the flexboard width. The lift force is estimated from the vertical acceleration (z″) of the vehicle during the first 3 cm of vertical flight (indicated by the circled data points), before the vehicle has noticeably tilted or moved laterally (note that for the flight in b, our lift estimate is based on data before the light has reached full intensity, because the vehicle has already moved and tilted noticeably by then).