Recorded flight data from two EC-130Q and two L-382G aircraft have been analyzed to perform operational airframe usage assessment and flight loads analysis. These aircraft were flown in support of USFS aerial firefighting missions during 2016 through 2019 for a total of 1,354 flights, which accounted for approximately 882 hours of flight time. For analysis, flights were divided into two types; firefighting and ferry/maintenance flights. Firefighting flights were also further separated into five different phases. Usage information was found for complete flights between takeoffs and landings. Aircraft statistical usage information regarding maximum altitude, maximum indicated airspeed, flaps usage, and vertical load factors is presented and compared between the two types of flights. It is shown that the aircraft were largely flown within the operational limits. Load factors exceedances spectra of gust and maneuver loads were developed and are presented for overall flights as well as for each firefighting flight phase. It is shown that the drop phase had the highest number of occurrences of both gust and maneuver loads. Comparisons were also made with results in the current literature. Derived gust velocities were compared with results in the current literature for similar airframes. The results showed that the firefighting flights occurred in an atmosphere with higher and more frequent gust velocities than that of the ferry/maintenance. Results of this study are expected to help aircraft operators determine how the current operational usage and flight loads differ from those for which the aircraft was originally designed. Once the differences are known, inspection and maintenance programs can then be adjusted accordingly.