An optical velocity sensor, based on the sheet-pair transit-time technology, was designed, built to flightworthy standards, and test flown on an F-16B to 50,000 ft and Mach 1.2, as part of an optoavionic air data system. Brief descriptions of the work leading to 24 flights in January and February 1990 are given, with examples of data and discussions of experiences. Compared with conventional pneumatic sensors the system offers advantages that include potential improvements in accuracy, latency, calibration, dynamic range of speed and attitude, robustness, and possibly life, cost, and range of application, without modification of the vehicle skin contour. Measurements corresponding well with the aircraft system were obtained under all conditions except heavy cloud, which demands small design changes for future systems. The importance of modeling for software and hardware design optimization is stressed and measurements are presented.