Abstract A method of measuring the horizontal and vertical turbulent components of the wind has been developed to meet the need for these measurements over the open ocean. An anemometer, a vertical accelerometer, and a gyroscope mounted in an airplane (U. S. Navy PRY-6A) yield simultaneous records of the total airspeed, vertical accelerations, and the attitude of the airplane. From these records, and from airplane-lift theory and the characteristics of the particular type of aircraft, the vertical and horizontal fluctuations of the wind, the root-mean-square deviation velocities, and the shearing stress can be computed. The method allows the phugoid oscillations of the airplane to contribute nearly periodic velocity terms to both components; these must be eliminated by a computational step. A different reduction method can give phugoid-free vertical velocities, but an additional instrument will be required for phugoid-free horizontal velocities. The airplane lift has a response of from 80 to 100 per cent ...