What happened
On the afternoon of 13 August 2003, a Robinson R44 ASTRO, registered G-HALE, was conducting a private flight between Donegal Airport (Carrickfin) and Arranmore Island. After an initial landing in a field on the island, the pilot returned to Carrickfin to refuel. Upon returning to the same field on Arranmore, the pilot attempted to adjust the approach to land into a new northwesterly wind direction. During this maneuver, the aircraft struck high-tension electricity cables located to the southeast of the landing area. The impact severed all three copper wires of a 10,000-volt three-phase system, resulting in a local power outage for several homes and businesses.
Following the strike, the pilot landed the aircraft and performed a personal inspection. Believing the helicopter was undamaged, the pilot conducted a short test flight before departing the island. There were no injuries to the pilot or the three passengers on board.
The investigation
The AAIU investigation focused on the circumstances of the wire strike and the subsequent actions taken by the pilot. Investigators examined the flight path changes necessitated by shifting wind conditions and the pilot's failure to perform a reconnaissance of the new approach path. The investigation also reviewed the aircraft's condition, noting that while the pilot had cleared the aircraft for flight, a professional inspection was not performed until the aircraft reached a contractor in Galway. That later inspection revealed a small dent on the underside of one main rotor blade.
Findings
- The collision with the electrical transmission wires was caused by the pilot's failure to properly survey the intended approach path for obstacles before landing.
- The pilot's decision to resume flight operations immediately after the strike, without a technical inspection by a qualified engineer, was identified as poor airmanship.
- The aircraft was operated without a professional assessment of potential structural damage following the impact with the high-voltage lines.