The Safety Board's full report is available at: http://www.ntsb.gov/publictn/2009/AAR0905.pdf. The Aircraft Accident Report number is NTSB/AAR-09/05. On March 4, 2008, about 1515 central standard time, a Cessna 500, N113SH, registered to Southwest Orthopedic & Sports Medicine Clinic PC of Oklahoma City, Oklahoma, entered a steep descent and crashed about 2 minutes after takeoff from Wiley Post Airport (PWA) in Oklahoma City. None of the entities associated with the flight claimed to be its operator. The pilot, the second pilot, and the three passengers were killed, and the airplane was destroyed by impact forces and postcrash fire. The flight was operated under 14 Code of Federal Regulations (CFR) Part 91 with an instrument flight rules flight plan filed. Visual meteorological conditions prevailed. The flight originated from the ramp of Interstate Helicopters (a 14 CFR Part 135 on-demand helicopter operator at PWA) and was en route to Mankato Regional Airport, Mankato, Minnesota, carrying company executives who worked for United Engines and United Holdings, LLC.