Several experienced pilots who were at Cheyenne Regional Airport at the time of the accident testified that they considered the weather at that time unsuitable for flight, as a thunderstorm seemed to be forming or moving over the airfield. In addition, investigators determined that the weight of the aircraft during its takeoff roll exceeded its maximum allowable takeoff weight (MTOW) by 96 lbs, which would have increased the stall speed by about two percent. Since the aircraft was flying in moderate to heavy rain, the NTSB calculated that the water flowing on the wings would have further increased the stall speed by about 1.5%. A higher stall speed reduces the margin of safety at slower airspeeds, such as during a climb.