What happened
On November 13, 2000, at approximately 14:15 local time, an Agusta A-109-A II (registration EC-HBQ) was conducting a flight verification and instruction mission near the La Juliana aerodrome in Seville. The flight, which began at the Isla de la Cartuja helipad, involved a pilot and an instructor performing various emergency procedure reviews, specifically focusing on autorotation maneuvers.
During the third attempt at a low-speed autorotation maneuver, the crew attempted to transition from the descent to a controlled approach. As the pilot applied collective pitch, the aircraft experienced an excessive rate of descent. In an effort to recover, the crew attempted to exit the maneuver; however, the aircraft struck the ground with its rear landing gear and tail stabilizer before returning to flight. After maintaining a hover for several minutes to check for vibrations or flight control damage, the crew decided to return to the Isla de la Cartuja helipad due to the visible damage to the landing gear. Upon arrival, ground personnel noted the damage, and the aircraft landed on its skids.
The investigation
The investigation established that the crew was practicing specific autorotation techniques designed to reach a precise point with minimal airspeed. During the final maneuver, the pilot initiated the power application (collective pitch) while the aircraft was at a low speed. The investigation focused on the aerodynamic response of the rotor system to the sudden change in pitch during the descent phase.