What happened
On March 5, 2015, an Airbus Helicopters BK117 B-2 arrived at the Katharinenhospital helipad in Stuttgart to perform a scheduled medical transfer of a patient to a specialized clinic in Neresheim. The helicopter crew, consisting of a pilot, a flight paramedic, and an emergency physician, landed on the hospital's rooftop pad at approximately 09:00 local time.
During the engine cooling phase, while the rotors were still spinning, a hospital employee entered the landing platform. The individual, who was authorized to access the pad to assist with patient transfers, walked toward the rear of the aircraft. As the employee moved around the tail boom, their head came into contact with the rotating tail rotor, resulting in one fatality.
According to the crew, no persons were visible on the landing pad during the approach or immediately after touchdown. After landing, the pilot reduced engine power to idle. The paramedic, who had already begun programming the navigation unit for the next flight, exited the aircraft to secure the area and prepare for the patient transfer. The crew noted unusual vibrations and a mechanical noise, leading the paramedic to discover the individual lying on the ground near the tail. The paramedic immediately signaled the pilot to shut down the engines.
The investigation
The BFU investigation established that the deceased was a 53-year-old hospital staff member with 25 years of service, who was experienced in assisting helicopter crews and had been trained in the helipad's safety regulations. The investigation also examined the physical characteristics of the BK117 B-2, noting that while the tail rotor disc height is typically 1.90 meters under normal loading, the sloping design of the helipad meant the tail rotor clearance was only approximately 1.55 meters above the ground at the time of the accident.
Witnesses observed the employee walking around the tail of the helicopter and turning near the left side of the tail boom just before the collision. A technician stationed at the eastern access stairs reported that they did not see the employee or the accident occur.
Findings
- The primary cause of the accident was the unauthorized entry into the tail rotor hazard zone by the hospital employee while the rotors were still in motion.
- The employee's height (approximately 1.82 m) relative to the reduced tail rotor clearance (1.55 m) at the specific landing position significantly contributed to the collision.
- There was no established radio communication between the helicopter crew and the hospital ground personnel at the landing site.
- While the hospital had established safety regulations and annual training for staff, the individual entered the landing area without the pilot's explicit signal to approach.