An in-depth assessment of the measurement uncertainties of the NCAR air motion systems characterizes this capability and is presented as a useful tool for determining wind data quality as it applies to research program specifications and recognizing subtle air data or Inertial system malfunctions. Table 3 contains the details of the random and systematic error values and the calculated measurement uncertainties at the 95% confidence level. An opportunity to compare the aircraft system air motion system with the ground based NOAA Profiler at Medicine Bow, WY provided a limited data set from which the lessons learned will be helpful with future intercomparison planning. At several levels, the wind direction is well within the expected uncertainty and, in general, the Profiler wind speeds are higher by 2-3 m/s than the aircraft system. The directional differences increase as the speed decreases - which is expected from the directional uncertainties. This is also an attempt to illustrate the value of measurement uncertainty of a popular meteorological measurement required for most NCAR research programs. Admittedly, the subtle intent is to encourage others in the community to routinely define "good" data as test data whose errors do not influence the drawing of valid test conclusions by adopting the measurement uncertainty procedures that are abundantly available.