A dramatic helicopter crash on Auckland's
waterfront was triggered when a rigging supervisor pulled a lifting line
so it hit the chopper's main rotor blades, a report states.
Greg
Gribble's Squirrel helicopter crashed in spectacular fashion on the
Viaduct wharf last month while erecting a seven-storey Telecom Christmas
Tree.
The incident was captured by news media and broadcast
around the world, with many saying it was a miracle Mr Gribble walked
away from the smash unscathed.
The Civil Aviation Authority (CAA)
released its preliminary report into the crash on Tuesday, saying
"massive out-of-balance forces" tore through the chopper after it struck
a lifting line.
Detailing how the November 23 accident occurred,
the report explained the helicopter was trying to lift the 25-metre
tower base for the festive tree from horizontal to vertical using a
lifting line.
The situation turned bad when it came time to release the line from the helicopter's hook.
"When
the rigging supervisor jumped up to grab the line, it instantly
tightened and touched the helicopter's main rotor blades," the CAA said.
"The force of the impact caused major structural damage and the aircraft hit the ground."
It
said the investigation was still continuing, and will focus on the
pre-flight safety briefings, the pilot's experience and training, health
and safety aspects and potential preventative measures that could have
been used.
The full report could take up to a year to be completed.
NZN