The Australian Transport Safety Bureau (ATSB) has released its final investigation report into the crash of a Bell 206 Jetranger at Olympic Park, Melbourne in November 2013.
The Jetranger, VH-VDZ, was being used to ferry customers between Olympic Park and Flemington Racecourse when it crashed whilst being repositioned in on a temporary helipad.
"As the pilot lifted the helicopter into a hover it started rolling about the right skid, which was in contact with the ground," the ATSB report states.
"The helicopter rapidly rolled further right until the main rotor blades struck the ground. A large amount of main rotor and other high energy debris was released from the helicopter and impacted a nearby marquee, a number of vehicles and a helicopter on an adjacent helipad. The pilot sustained minor injuries.
Despite the flying debris, no-one on the ground was hurt.
According to the ATSB, the pilot did not identify and react to the helicopter’s right-skid low attitude in time to prevent the helicopter rolling over. It also found that a ballast bag was stored on the left front floor of the Jetranger, and that the left cyclic had been removed.
"The person who removed the controls did not have the training or authorisation to conduct the maintenance procedure. The left cyclic stub cover was not installed, leaving the stub exposed. This resulted in the potential for the ballast bag to inhibit movement of the pilot’s cyclic control due to fouling of the left cyclic stub."
Among the ATSB conclusions, was one stressing the importance of immediate reaction to rollover forces.
"This accident highlights the importance of coordinated control inputs by pilots during lift-off to control any roll, and if necessary smoothly lowering the collective in coordination with cyclic input to re-establish the helicopter’s weight evenly on the ground before any roll becomes excessive."
The full report is on the ATSB website.