As part of the ALOHA/ANLC-93 campaign to investigate atmospheric dynamics, in situ wind measurements collected at 6 km with the gust probe sensor attached to the National Center for Atmospheric Research Electra aircraft were analyzed for 16 flight segments between 61 ¿N and 14 ¿S and between 92 ¿W and 170 ¿W over land and water. Horizontal wavenumber spectra for the vertical wind and both zonal and meridional horizontal-wind components were calculated. The zonal and meridional wavenumber spectra exhibited a decrease in the spectral slope from ~-1.98¿0.02 for wavelengths between 2 km and 100 km to ~-3.18¿0.06 for the longer wavelengths between ~100 km and ~330 km. The wavenumber spectrum for the vertical wind component showed a 2 power law dependence for wavelengths in excess of 5 km and a generally flat shape at shorter wavelengths. An increase in power at the wavelength of ~10 km was detected for the meridional wavenumber spectrum. These results were compared with predictions from two spectral models and with spectral results from other observations. ¿ 1998 American Geophysical Union