What happened
On May 17, 2018, a Sikorsky S76B helicopter, registration N76VR, was attempting a private departure from the Valle Nuevo helipad in Constanza, Dominican Republic. The aircraft was operating at an elevation of approximately 7,668 feet above sea level with two crew members and six passengers on board.
During the takeoff roll, the pilot identified pine trees, ranging from 50 to 130 feet in height, located approximately 257 meters (843 feet) ahead along the departure path. In an attempt to avoid colliding with these obstacles, the pilot executed a 180-degree right turn. During this maneuver, the aircraft experienced a progressive loss of lift and entered a steep descent, ultimately impacting the terrain on its left side with significant energy. All eight occupants escaped the accident without injuries, though the aircraft sustained severe damage.
The investigation
The CIAA investigation focused on the aircraft's performance capabilities under the specific environmental conditions at the time of the accident. Investigators analyzed the takeoff weight, altitude, and temperature to determine the required takeoff distance and the aircraft's ability to maintain flight.
Key elements examined included:
- The available takeoff distance versus the required distance for a Category B takeoff.
- The aircraft's weight relative to its Out-of-Ground-Effect (OGE) hover capability.
- The pilot's adherence to the manufacturer's recommended takeoff procedures.
- The impact of environmental factors, such as high density altitude and terrain obstacles.
Findings
- The available takeoff area was approximately 843 feet, which was roughly 450 feet short of the 1,300 feet required for a safe Category B takeoff under the prevailing weight, altitude, and temperature conditions.
- The aircraft's weight exceeded its capability to perform a hover out-of-ground-effect (OGE) at the time of the event.
- The pilot failed to perform a power check via a hover at approximately 5 feet above the ground, a critical step in the manufacturer's prescribed Category B takeoff procedure.
- The combination of high density altitude, high weight, and the presence of tall obstacles placed the aircraft at the extreme edge of its operational limits.