Investigation number
199300092
Occurrence date
State
Tasmania
Report release date
Report status
Final
Investigation type
Occurrence Investigation
Investigation status
Completed
Occurrence class
Accident

During the procedure turn at the end of a spray run the engine power failed. During the ensueing forced landing the pilot had to overpitch the rotor to avoid power lines. The helicopter landed heavily fracturing the tail boom, damaging the main rotor blades, and collapsing the skids. Inspection of the engine disclosed that the left exhaust pipe had fractured inside the carburettor heat shroud. The exhaust gases were then ingested by the engine with consequent total loss of power. The exhaust pipe fracture was caused by fatigue occasioned by the unsupported nature of the installation. The shroud would have masked the fracture growth, which was not in evidence at the last inspection some 40 hours prior to failure. Significant Factors: 1. The engine power failed due to a fractured exhaust pipe. 2. The pilot was forced to overpitch to avoid obstructions. 3. The helicopter landed heavily.

Aircraft Details
Manufacturer
Hiller Aviation
Model
UH-12E
Registration
VH-AGK
Sector
Helicopter
Departure point
Nabageena TAS
Destination
Nabageena TAS
Damage
Substantial