Data obtained from digital flight data recorders installed on a fleet of 27 Beech 1900D airliners are used to assess the actual operational environment of propellers on commuter aircraft. The data consists of 910 complete flights and 589 flight hours. The short duration takeoff rotation is identified as the most severe phase of operation with regard to vibratory loads on the propeller blades resulting from a tilted inflow angle. Also, normal accelerations data, which reflect the turbulence experienced in flight, is converted to the resulting change in the propeller inflow angle. Increasing altitude shows a significant reduction in the frequency and magnitude of the inflow angle variation caused by gusts. The information is presented in statistical formats that could enable the FAA, manufacturers and operators to better understand and control those factors that influence the structural integrity of these components