What happened
On March 7, 2001, an Aerospatiale AS-350B helicopter, registration D-HAFT, was operating an emergency medical mission in Mallorca, Spain. The aircraft, operated by the German company Heli Flight Gmbh & .Co Kg, had been deployed to the island to perform urgent medical transfers.
After receiving a request to rescue an unconscious individual near Andraitx, the pilot, accompanied by a doctor and a paramedic, flew to the specified mountainous area. Upon arrival, the crew identified a small, relatively flat clearing on a mountainside surrounded by dense pine trees. The pilot landed the aircraft with the nose facing the mountainside. After landing, the crew met with a person on the ground who informed them that the patient had already been transported to a medical center in Andraitx.
Following a telephone confirmation, the crew decided to proceed to Andraitx to collect the patient. The crew re-boarded the aircraft, and the pilot attempted to take off using the same flight path used during the initial landing. As the helicopter ascended to approximately 3 meters above the ground, the tail rotor struck a pine tree branch. This impact caused the aircraft to lose control and drift to the right, leading the main rotor blades to strike several other trees. The helicopter subsequently crashed into the ground, coming to rest on its right side. There was no post-crash fire.
The investigation
The investigation established that the pilot intended to execute a maneuver involving an initial climb followed by a 180-degree vertical axis rotation to face the valley before continuing the takeoff. During this rotation, the tail rotor made contact with a tree branch.
Investigators noted that during a rotation around the vertical axis, the tail describes a circle centered on the main rotor mast. Because the pilot cannot see the tail from the cockpit, the maneuver requires precise environmental assessment or external guidance. In this instance, although a crew member was providing visual cues regarding tree clearance, the limited space and the margin for error were extremely small.
Findings
- The tail rotor strike with a tree branch was the primary factor leading to the loss of control.
- The maneuver was performed in a highly constrained environment with significant obstacles (pine trees) in close proximity.
- The pilot's evaluation or execution of the takeoff maneuver was insufficient given the reduced margins for error provided by the terrain.