LAX06FA069 · McDonnell Douglas 369FF

The helicopter was dispatched on an external load, fire suppression mission. A 25-foot line and 140-gallon Bambi Bucket were attached to the helicopter's cargo hook. The pilot then flew to a reservoir to pick up the first load of water. There were no witnesses at the reservoir; however, witnesses nearby observed the helicopter drop down towards the reservoir behind a tree line and then rise back up above the tree line. Two witnesses provided conflicting statements. One reported that the helicopter spun rapidly in a clockwise direction, then stopped spinning and descended slowly back out of view below the tree line. This witness reported that he could not hear the engine. The other witness reported that the helicopter spun violently in a counterclockwise direction, and the engine was loud, then "shutdown or stalled," and the helicopter stopped spinning and descended slowly out of view. The helicopter was found approximately 10 feet from shore completely submerged in the reservoir with the exception of the right skid, which protruded from the water. Small trees, with limb diameters ranging between 1 and 2 inches, were freshly cut along the bank in the vicinity of the helicopter. Examination of the helicopter after it was recovered from the reservoir revealed damage consistent with the fuselage impacting the water in a level roll attitude with a nose down pitch attitude. Damage to the main rotor blades indicated that they were rotating at nominal operational RPM at the time of impact. No evidence of any preimpact mechanical malfunction was found during the examination. Disassembly of the engine, fuel control, and power turbine governor revealed no evidence of any anomalies that would have prevented the engine from producing power prior to impact. The engine's compressor impeller exhibited foreign object damage to several blades with the blade tips torn and bent opposite the direction of rotation, indicating that the compressor was rotating when the damage occurred. Approximately two months prior to the accident, the pilot reported having 430 hours helicopter flight time of which 70 hours were in the accident make and model helicopter. Approximately two weeks before the accident, he was issued a Statement of Competency for external load operations by the operator's chief pilot. Operator personnel reported that the accident flight was the pilot's first solo external load flight.

Verbatim NTSB analysis and probable cause from the NTSB dataset