An NTSB interim factual report and findings from a flight simulation issued last month suggest that pilot error, not a runaway trim condition, caused the June 4, 2007 crash of a Cessna Citation II into Lake Michigan three minutes after takeoff from Milwaukee General Mitchell International Airport. The two crew and four passengers aboard N550BP were killed in the accident. Recordings retrieved from the airplane’s cockpit voice recorder indicated that the captain was “fighting the controls” and had a “runaway trim.” However, findings from a simulation conducted by the NTSB’s recorded radar and airplane performance study group “are consistent with the copilot inadvertently hitting the autopilot button” instead of the yaw damper. The study group said that an engaged autopilot could have resisted the captain’s efforts to control the Citation. The NTSB has not yet issued any probable causes for this accident.