What happened
On December 18, 1999, a Hughes 269C helicopter, registration ZK-HYE, was involved in a fatal accident approximately 3 nautical miles north of Kawerau, New Zealand. The aircraft was performing a private flight for the pilot's family following a successful check flight earlier that day.
After taking off from a farm paddock, the helicopter climbed to roughly 500 feet and completed a circuit of the property. During the return approach, the pilot descended to approximately 15 feet above the ground. As the aircraft moved toward a landing spot near an implement shed, the rotor blades struck an 11,000-volt power line. The impact caused the helicopter to roll and tumble, striking the ground in a nearly inverted position. The collision ruptured the fuel tank, triggering an intense fire that destroyed the aircraft and claimed the lives of the three occupants (the pilot and two passengers).
The investigation
Investigators examined the flight path, the aircraft's maintenance history, and the environmental conditions at the site. The investigation confirmed that ZK-HYE was well-maintained, with all service records up to date and the aircraft operating within its weight and balance limits. The weather was overcast but provided sufficient visibility, and the pilot's medical restrictions regarding color perception and myopia were not found to have contributed to the accident, as the pilot was wearing correct prescription lenses.
Findings
- The primary cause of the accident was that the pilot likely failed to detect the power line during the final approach.
- The approach path was such that the supporting poles for the wires were either hidden by trees or blended into the background of other utility poles.
- The wires themselves had become dull due to weathering, making them difficult to see against the backdrop of trees.
- The pilot's low-level flight path caused the wires to move out of his primary field of view.
- While the ground impact itself may have been survivable, the immediate and intense fire made escape impossible.
- The pilot had limited experience operating helicopters in non-aerodrome environments.