What happened
During a departure from runway 18 at Merrill C. Meigs Field in Chicago, Illinois, a Beechcraft King Air failed to rotate properly before impacting Lake Michigan. The aircraft struck the water approximately 300 feet south of the runway threshold. Air traffic control observations indicated that the plane had not lifted its nose by the three-quarter point of the runway. An observer at the airport noted an unusual pulsating sound during the takeoff roll and observed the aircraft bouncing on its landing gear struts without leaving the ground.
Findings
Investigation into the aircraft's control systems revealed physical damage to the pilot's control yoke, specifically small distortions in the holes of the column and the rod intended for the control lock. A minor crack was identified near one of the holes in the control lock rod. The control lock being used was a non-standard substitute for the original manufacturer equipment. Examination of this lock showed scratches parallel to the pin and a small deformation near the top of the pin.
Further investigation into cockpit procedures revealed that the flight department's third pilot routinely stored the control lock in a side wall pocket alongside a car key and a remote garage door opener. Both the key and the opener were located in that pocket during the investigation. The control lock itself was retrieved from the lake seven days after the accident. The investigation focused on whether the improperly secured control lock or its placement interfered with the flight controls.