Experimental measurements of the magnitude of air drag on the filament and the air velocity profile around the filament in the spinning and drawing down of a fiber filament in the surrounding of stagnant air are reported. The results are examined in comparison with the existing theoretical correlations that have been used in the studies of the spinning processes. The experimental values of the air drag are found to be larger than the values based on the existing correlations to such an extent that, in some cases of past studies, the air drag effect on the filament tension may have been underestimated.