What happened
On April 6, 2011, a pilot operating an Avions Pierre Robin HR 200/100 departed from Marl-Loemühle for a visual flight rules (VFR) flight to Würzburg (Schenkenturm). During the flight, the pilot navigated along the A43 and A4/A45 motorways, maintaining an altitude between 250 and 400 feet above ground level. The pilot reported that a southward turn near Hagen was not possible due to hills obscured by fog.
At approximately 09:18, north of Meinerzhagen, the aircraft collided with the earth wire of a high-voltage power line. The wire, which is positioned approximately 36 meters (120 feet) above the motorway, was severed by the impact. Following the collision, the pilot climbed through the cloud layer to approximately 3,500 feet AMSL. The pilot noted damage to the right wing and a slight engine imbalance, though the engine continued to operate without significant vibration at 2,300 RPM. The pilot eventually landed at Würzburg without further incident.
The investigation
The BFU investigation utilized data from a handheld GPS device carried by the pilot to reconstruct the flight path and altitude. The investigation also examined the physical damage to the aircraft and the specific characteristics of the power line infrastructure.
Findings
- The aircraft sustained light damage to a propeller blade, the right side of the engine cowling, and the leading edge and spar of the right wing.
- The collision occurred with the earth wire of a high-voltage line running northwest to southwest.
- At the time of the accident, weather conditions in the area were characterized by low cloud ceilings (between 200 and 600 feet) and low visibility, with the local GAFOR weather rating being X (closed), indicating that VFR flight was not possible due to visibility and cloud base.
- The pilot chose to fly along the A45 motorway because they believed this route offered fewer obstacles, such as wind turbines.