The helicopter which crashed immediately after taking off on Palm Jumeirah, Dubai, earlier this year, spun 50 times before hitting the ground, the UAE General Civil Aviation Authority (GCAA) has said in a report.
The report found that the helicopter was airworthy and the engine, airframe and system architecture examinations did not indicate any pre-existing faults.
The report didn’t specify any reason for the crash.
The helicopter, operated by Helidubai, had operated six passenger tourist flights over Dubai prior to the accidents on January 22, 2014.
The report found that the helicopter hit the helipad vertically on collision, in a level attitude, with minimal forward speed, nose down and with a rapid rate of descent, resulting in a hard landing.
The loss of the tail rotor control occurred as the helicopter was engaged in a counter-clockwise rotation following the heavy landing; subsequently as the helicopter was under power, it then began uncontrolled rapid counter-clockwise rotation.
The tail rotor assembly separated from the tail boom early in the ground rotation phase following numerous collisions with curb structures adjacent to the heliport.
The copter remained on the helipad with the engine running and the damaged rotor blades continued turning while the helicopter was moving down the heliport extended centreline.
The helicopter made approximately 50 rotations on the helipad prior to contacting a retaining wall, which arrested the rotation.
The aircraft remained in that position with the engine running and the damaged rotor blades turning. The heliport ground crew then shut down the engine and assisted with removal of the incapacitated crew.
Both the pilot and the helicopter landing officer sustained serious injuries in the accident and were airlifted to a local hospital.
The report found that the helicopter and heliport periphery were extensively damaged due to the rapid descent and abnormal contact with the heliport, followed by the uncontrolled rotation of the helicopter on the heliports’ extended centre-line.
A final report will be published within 12 months of the date of accident.