20000516043669A

(-23) The following narrative was developed through the cooperation and on site investigation of personnel from the allegheny flight standards district office and the northeast regional office of the national transportation safety board. On may 16th, 2000, at approximately 1900 hours eastern daylight savings time, a Bell UH-1H helicopter, N52AG, was performing aerial application flight operations in the vicinity of Frenchville, Pennsylvania, when it was destroyed upon impact with terrain in a state park. The commercially rated pilot was fatally injured in the accident. Prior to this accident, the helicopter had conducted three other spray operations in the same area on this day. The aircraft had departed a remote landing area for its fourth spray operation of the day. According to an onboard sensor, the aircraft departed the remote landing area at 1858 hours. The last reading on the remote sensor was at 1859 hours and 14 seconds at a position approximately 1.4 miles northeast of the remote landing area. Approximately 4000 feet farther northeast of the last sensor position, the aircraft was found inverted on the side of a hill. The helicopter came to rest inverted, on a magnetic heading of approximately 355 degrees. Trees in the area averaged 70 feet in height and two feet in diameter. Approximately 200 feet to the southwest of the main wreckage, several treetops were observed having freshly broken branches. In an area below the treetops, components of the aircraft's onboard spray system were found. At the site of the main wreckage area, there was also damage to treetops and scrapes that extended along the tree trunks to the ground adjacent to the wreckage site. The majority of the impact damage was from the nose of the aircraft to a point approximately six feet aft. The spray tank, containing approximately 300 gallons of a non-toxic agent, was damaged allowing the contents to spill on the ground throughout the wreckage site. The cabin area was collapsed from the transmission area towards the nose. The transmission was pulled out of the aircraft along with the rotor system, which remained intact. Aft of the transmission area, there was minimal damage to the engine cowling, tail boom and tail rotor. The main drive shaft was separated from the engine and transmission and was found lying adjacent to the transmission area. The main rotor system was found intact and attached to the mast of the transmission. Damage on the main rotor blades was found aft of the leading edge with sections of the honeycomb area missing but lying in clow proximity to the aircraft. The aircraft was removed from the crash site on may 17th, 2000, and was placed in a hangar at the clearfield airport, clearfield, Pennsylvania, for further examination by the national transportation safety board, FAA, and representatives of Bell helicopter. During this examination, it was found that both engine mounts were fractured and the air inlet screens had separated from the aircraft. The compressor section was visible, and foreign object damage was found on the trailing edges of the first and second stage compressor blades. Examination of the exhaust section of the engine revealed no damage to the turbine section. The aircraft was found to have approximately 1000 pounds of fuel onboard, and the fuel system appeared to be operating normally. A fuel sample was taken at the accident scene as well as the hangar; however, no water was observed and only a very few small pieces of organic material was found in the fuel. Control continuity was established for both the main rotor and tail rotor systems. Power train continuity was also established from the engine to the transmission and the transmission to the tail rotor.