Accident Details
On 11 March 2011 at 13:20 UTC, a Robinson R44 II helicopter, registered OO-PTA, was involved in an accident in Bredene, Belgium. The helicopter was owned and piloted by a 39-year-old male private pilot. He had recently returned from a two-week ATPL training course in the United Kingdom. The weather was favorable, and he invited two friends for a leisure flight.
The helicopter took off from Zeebrugge at approximately 13:02 UTC. The flight preparation did not include a study of the Low-Air chart in the vicinity of Bredene. The helicopter flew toward Bredene, where the passengers resided, with the intention of taking pictures near their homes. The pilot contacted Oostende Tower (EBOS) for authorization to enter the control zone, reporting an altitude of 500 feet or below. The helicopter flew at altitudes between 200 and 400 feet above ground level over Bredene.
After circling the water tower, the helicopter proceeded south toward the Nukkerwijk and Nukkerbrug, where a 150 kV power line (Brugge–Slijkens) runs. The helicopter's path was perpendicular to the power line. Approaching the bridge at an altitude of 130 feet, the helicopter turned left. The pilot did not notice the power line until he saw a shadow and heard a loud bang. The main rotor severed the ground wire of the power line.
The pilot brought the helicopter down cautiously. After hovering to check for damage, he landed next to the power pole. The pilot and passengers exited uninjured.
Aircraft and Crew Information
The Robinson R44 II (serial number 11445, built 2006) had a total airframe time of 505.4 hours. The engine was a Lycoming IO-540-AE1A5. The pilot held a Private Pilot License (Helicopters) issued 8 August 2008, with valid ratings for the R22 and R44. He had approximately 300 total flight hours, of which 220 were on the R44. His medical certificate was valid until 8 April 2012.
Damage
The aircraft sustained damage to the main rotor, rotor mast, windscreen, and cabin structure (punctured). The ground wire of the high-voltage line was severed.
Meteorological and Navigational Aids
At 13:20 UTC, weather at Oostende Airport (EBOS) was wind 270° at 11 knots, visibility more than 10 km, few clouds at 3000 ft, temperature 10°C, dew point -1°C. The sun azimuth was 204.36° with elevation 32.35°. The helicopter was equipped with two GPS units. Radar tracking showed the helicopter only when above 300 feet; below that, tracking was lost. The presence of the 150 kV power line was clearly identified on the M534 Low-Air Chart (Ed 2010).
Communication
Radio communication with Oostende Tower was established at 13:03:13 UTC. The transcript indicates routine exchanges. At 13:20:55, OO-PTA called the tower, reporting "we just hit a high-tension cable." The tower acknowledged and offered assistance. The pilot reported the helicopter was on the ground, no injuries, and requested the power line be switched off. The tower confirmed the line was disconnected.
Conclusions
The investigation determined the probable cause: the pilot did not identify a high-voltage power line while maneuvering at low altitude.