What happened
On October 11, 2003, a DR 400/180R performing a glider tow operation departed from the Bad Neuenahr-Ahrweiler (EDRA) airfield. After releasing a glider at approximately 2,000 ft, the pilot began the return to the airfield. During the approach to runway 29, the pilot activated the electric winch to retract the tow rope. The pilot observed the control light on the switch flicker and then the switch return to its original position, which led the pilot to believe the rope had been fully retracted.
However, the rope remained trailing behind the aircraft. As the aircraft entered the final approach, a ground instructor noticed the rope hanging from the aircraft and radioed a warning to the pilot. Despite this warning, the approach continued without visible change. Simultaneously, two pedestrians were walking on a service path located just below the airfield level, directly in the path of the runway 2 and approach zone. The trailing rope struck the pedestrians, causing the rope to break. The impact resulted in one serious injury and one minor injury.
The investigation
The BFU investigation focused on the functionality of the winch system and the visibility of the rope. It was established that the aircraft's winch system was missing a required rearview mirror on the left wing, which was intended to allow the pilot to visually confirm the rope's status. While the electrical switch and indicator light functioned, they only indicated that the winch was powered, not that the rope was fully wound. The investigation also examined the placement of warning signs at the airfield, noting that existing signs were faded and positioned in a way that suggested danger was limited to the airfield grounds rather than the approach path below.
Findings
- The pilot proceeded with the landing descent under the false assumption that the tow rope had been fully retracted.
- The aircraft was missing a mandatory rearview mirror, which prevented the pilot from visually verifying the rope's position.
- The electrical indicator light and switch provided ambiguous information, as the switch's return to the