The helicopters main rotor blades came into contact with a tree during a low-level fence inspection operation. The helicopter then descended out of control into a flooded river and submerged. The pilot and observer egressed safely from under the water.
The pilot reported that he had manoeuvred the aircraft to within about 10 metres of some tall trees beside the river, in order to give the observer the best possible view of a section of fence. At this point the helicopter yawed left and the main rotor blades struck a tree. Later the pilot said that he though the tail rotor blades may also have struck a tree. After the tree strike the pilot had insufficient control and was unable to prevent the aircraft descending sideways into the river.
The wreckage was not recovered from the river for several weeks, due to flooding and continuing torrential rain. Later examination of the wreckage did not reveal any pre-existing mechanical fault which may have contributed to the accident. The tail rotor assembly was found to be intact and attached to the boom. No evidence was found to indicate the tail rotor blades came into contact with the tree.