What happened
On August 14, 2016, at approximately 4:40 p.m., an Aérospatiale AS-355F2 helicopter, registration HI-861, was performing a private flight from La Vega to Aeropuerto Internacional Dr. Joaquín Balaguer (MDJB) in Santo Domingo, Dominican Republic.
During the final approach to Helipad Y (Yanki), the pilot observed another aircraft positioned on the runway preparing for takeoff. To avoid a conflict, the pilot accelerated the approach. Upon realizing the aircraft was approaching the landing point at a higher speed than desired, the pilot lowered the collective to reduce airspeed. This maneuver caused the helicopter to enter a power-on sink from an altitude of approximately 50 feet, resulting in a hard landing.
The impact against the ground caused the landing skids to break and the fuselage to undergo vertical compression. The energy of the impact triggered a resonance that caused the aircraft to disintegrate, scattering debris across a 26-meter radius. The pilot, the sole occupant, sustained serious injuries, including craniofacial trauma, a concussion, and nasal fractures.
The investigation
The CIAA investigation examined the aircraft's maintenance records, engine components, and the pilot's flight history. Investigators also analyzed witness videos and photographs of the wreckage. The investigation confirmed that the engines were functioning correctly and producing power at the moment of impact. The aircraft's airworthiness was current, with the last annual inspection completed in June 2016. Meteorological conditions at the time were found to be favorable for flight operations.
Findings
- The pilot's decision to perform a rapid deceleration maneuver to manage airspeed led to a power-on sink.
- The sudden descent caused a high-energy impact with the terrain.
- The mechanical destruction of the aircraft was a result of the impact energy and subsequent structural resonance.