What happened
Prior to takeoff, the pilot received several weather updates and briefings. These included two pilot reports of windshear involving other aircraft on the approach into Appleton. Shortly after the departure of N87163, the radar controller transmitted Convective SIGMET 1E on the same frequency, which indicated the presence of embedded thunderstorms.
Approximately 10 minutes later, while being vectored for an approach into Appleton, the pilot received various heading deviations due to weather conditions. During this time, a witness located between the OM and MM for the ILS approach reported experiencing a "huge downpour" accompanied by "very strong winds." The aircraft subsequently crashed 1/2 mile from the approach end of the runway.
The investigation
An examination of the wreckage determined that all power controls for both engines were positioned in the full forward position. Additionally, investigators found that the left and right main landing gear mounting trunnions had been displaced upward into the wing fuel tanks.