The crash of an Australian army Sikorsky S-70A Black Hawk helicopter while attempting to land on HMAS Kanimbla off Suva, Fiji, in November 2006 has been attributed to pilot error, but a number of other factors culminated in the accident, according to the report of a Board of Inquiry investigation.
The Black Hawk was carrying four crew and six soldiers from the Special Air Service regiment when it crashed and sank while conducting a special operations approach and attempting to land on the ship.
The manoeuvre, conducted with strong tail winds, pushed the helicopter to its operational limits and resulted in main rotor droop.
Early in the descent, which was near vertical, the helicopter entered a vortex ring state from which recovery was not possible. The pilot died from injuries received in the crash and one passenger drowned.
Factors that contributed to the crash include "a gradual adoption of approach profiles which on occasions, exceeded the limits of the aircraft", says Air Chief Marshal Angus Houston, chief of the Australian Defence Force.
Other factors include a "can-do" culture in the 171 Aviation Squadron, inadequate supervision, the pressures of preparing for operations and a high operational tempo, he adds.
The board found that basic airmanship considerations specified in the Black Hawk standards manual were not fully applied when developing tactics and techniques, and unsafe practices had emerged.
Aviation risk management was not adequately processed, with hazards not identified and addressed, says the report.
The ADF has agreed to 56 of the 58 recommendations of the report, with the other two already adopted.
Recommendations include regular external auditing of the squadron to validate flying tactics, techniques and procedures against doctrine and approved flying standards, and redesigning the special operations approach.
In addition, the report recommends a detailed review be conducted into fitting the army's Black Hawk fleet with flotation devices.
The ADF says the army has already implemented a number of initiatives to improve safety, including a new risk-management policy and a new approach procedure that maintains appropriate safety margins.
Source: FlightGlobal.com
