What happened
On April 27, 2001, at approximately 10:51 AM CEST, an Agusta A109A II helicopter was conducting a commercial VFR flight from Porta Westfal and was en route to the Arnsberg landing field to pick up a passenger. During the approach, the aircraft was observed by witnesses flying at high speed and low altitude directly over the treetops of the Arnsberg State Forest, positioned approximately 4 NM east and 1.5 NM south of the destination.
While traversing the forest, the helicopter made contact with the trees. This impact triggered a fire, and the aircraft continued to slide through the forest, creating a 140-meter-long path of destruction approximately 40 meters wide. The impact and subsequent fire caused the total destruction of the aircraft. The pilot sustained fatal injuries due to central paralysis and cardiovascular failure.
The investigation
The BFU investigation examined the aircraft's technical condition, the meteorological environment, and the flight path. Technical inspections of the wreckage were severely limited due to the high degree of destruction; however, no evidence of mechanical failure was found. The investigation noted that the aircraft's airspeed indicator was reading 196 knots at the time of the crash, which was outside the green operating range. The aircraft's maintenance records showed that all required inspections and engine changes had been performed according to the approved program.
Meteorological data indicated that a cold front was moving through the area, bringing light rain and intermittent heavy showers. While horizontal visibility at ground level was between 10 and 15 km, it was likely reduced to between 4 and 6 km in certain areas due to the weather conditions.
Findings
- The pilot was flying at a low altitude over the forest, which was likely influenced by deteriorating VFR weather conditions.
- The flight path was inconsistent with standard procedures; the aircraft was observed significantly off-course, as the pilot could have flown directly to the destination without the deviation observed.
- The aircraft struck the trees while in a normal flight attitude, likely at cruising speed.