20000724023449A

(-23) On July 24, 2000, at about 0230 EDT, a Eurocopter AS350B, N911AM, returning to Sylvester, GA from a patient drop off in savannah, GA., was destroyed when it impacted the fround at a high vertical rate of descent in a marshy wooded area about 10 nautical miles west of tiffany, GA. There were 3 fatalities; the pilot, flight nurse, and flight paramedic. The weather reported at southwest Georgia regional airport (aby), albany, GA. About 27 miles to the west during the time frame was 7500' scattered with 7 miles visibility. Witnesses observing the helicopter overflight, about 2 miles from the accident site, indicated it was clear and stars were visible. There was no evidence of mechanical failure of any component. The engine tear down revealed that the engine had power at impact. None of the leading edges of the tail rotor nor the main rotor nor the main rotor systems had damage from tree strikes. It is important at this time to note that there were numerous trees at the accident site that none of the rotor blades contacted on the leading edges. (Con't) only one tree at the site had a major impact, this was from the main rotor blade grip assembly. The blade grip assembly is that part of the main rotor assembly near the center where the blades are attached. There were tree wood fragments in this portion of the main rotor assembly indicating impact with the tree. The ground impact heading, although primarily vertical, was 330 degrees magnetic. The major impact heading was determined from the helicopter landing skid (skids) that remained stuck in the ground after impact. There was a secondary debris field about 050 degrees magnetic (80 degrees to the right of the primary impact headings). Blade rotation direction and the dynamics of tree contact would account for this secondary debris pattern. The helicopter struck the ground at a high rate of descent about 60 degrees nose down. The front portion of the skids remained in the groundat about a 60 degree nose down angle. The helicopter fuselage separated, along with the engine, main rotor system and transmission, which impacted the ground in front of the skids. There was about a five (5) feet deep crater forward of the skids which contained the engine and transmission, indicating little horizontal impact angle. The main rotor assembly was just forward of the crater and one blade was buried in the mud to a depth of around 2 feet, most likely due to rotor rotation. The tail boom portion separated and remained to the rear of the skids that were stuck in the fround. The attitude of the helicopter as it entered the top of the trees was around 60 degrees nose down and about 80 to 90 degrees left bank. This attitude could explain why there was no rotor blade leading edge contact with any of the numberous trees in the accident site. The helicopter was rolled more level when the blade grip assembly struck a tree; again, there was no leading edge damage to any turning rotor system. It is not possible to determine the cause of the accident with the available data at this time, only that there was apparently a loss of control of the helicopter. An amended report will be filed later when more data becomes available.