What happened
On August 31, 2009, at 08:00 UTC, a Kamov KA-32A11BC (registration CS-HMK) operated by EMA – Empresa de Meios Aéreely was performing a takeoff from the Guarda Hospital Heliport. The aircraft had been mobilized by the National Authority for Civil Protection (ANPC) to combat a large-scale forest fire in the Ribeira da Nave area, Sabugal.
At the time of the operation, a Eurocopter AS350 (registration D-HAUR), operated by HeliPortugal, was parked on the grass approximately 40 meters north of the takeoff centerline. As the CS-HMK commenced its takeoff roll and transitioned forward, the powerful downwash produced by its rotors reached the stationary aircraft. This movement of air caused the main rotor blades of the D-HAUR to move violently, resulting in a collision between the blades and the helicopter's own structure.
The investigation
The GPIAAF investigation focused on the proximity of the two aircraft and the aerodynamic effects of the departing heavy helicopter. The investigation established that the D-HAUR was positioned within the reach of the air mass displacement caused by the CS-HMK's takeoff. The investigators examined the physical damage to the parked aircraft, which included a tear in the tail rotor drive shaft protection, damage to the main rotor blades, and damage to the Starflex unit.
Findings
- The primary cause of the incident was the impact of the Eurocopter's main rotor blades against its own structural components due to the intense downwash generated by the departing Kamov.
- The Eurocopter AS350 sustained damage to its main rotor blades, the Starflex, and the tail rotor drive shaft protection skin.
- There were no injuries to the crew members involved in either operation.