The victims of the Carterton balloon crash might have survived if the pilot had decided to immediately descend when it became clear the balloon would strike power lines, an investigation has found.
Instead, pilot Lance Hopping made the fatal decision, likely while he was under the influence of cannabis, to try to out-climb the power lines.
The findings of a Transport Accident Investigation Commission (TAIC) inquiry into the January 2012 tragedy were released today.
Eleven people were killed when the balloon caught fire and crashed to the ground after hitting power lines near Carterton on January 7.
The report comes after an interim report, released in May last year, found Mr Hopping, 53, had cannabis in his system.
The interim report said it was not known whether that was a factor in the crash - but the final report found the crash was caused by errors of judgment, and the possibility that Mr Hopping's performance was impaired by cannabis could not be excluded.
It was "highly likely" that Mr Hopping had smoked cannabis shortly before the fatal flight, with two witnesses saying they saw him smoking only about 25 minutes before the flight.
Toxicology results found he had 2 micrograms of cannabis per litre of blood, which was consistent with smoking cannabis 4-6 hours prior, and that he was unlikely to have been smoking tobacco.
The report pointed to errors of judgment that could have been linked to his smoking cannabis.
Among those was the decision not to rapidly descend once the balloon struck the powerlines, which was the advice given in the balloon flight manual.
"Had he done so there would have been a better chance of survival for the balloon's occupants," the TAIC found.
Instead, Mr Hopping tried to out-climb the power lines, which the TAIC said was an error in judgment.
The TAIC found it was highly likely that Mr Hopping knew the location of the power lines and had seen them before allowing the balloon to descend to their height.
A last-minute change in the wind carried the balloon towards the lines, two of which became stuck on the balloon's basket. The pilot applied the burners, causing the balloon to climb along the snagged power lines, while passengers tried to push the power lines off with their hands,
Electrical arcing from the power lines punctured the balloon's LPG tanks, causing an intense fuel-fed fire that consumed the basket.
Heat from the basket and, to a lesser extent, the decision of two passengers to leap from the balloon while it was still 20m off the ground, caused it to rapidly rise and break free of the power lines.
The balloon continued to rise before plummeting to the ground, killing all nine who remained on board.
The report addressed speculation the balloon's rapid rise was caused by two passengers jumping off, noting the speed of the balloon's ascent was significantly higher than expected had the load been lightened by two passengers alone.
The TAIC found Mr Hopping did not have a current medical certificate, which showed a disregard for complying with the rules.
Its said the use of drugs like cannabis by the crew of any transport vehicle was a serious safety issue that needed to be addressed as a matter of priority.
The report said the regulatory oversight of commercial ballooning in New Zealand was not sufficient to ensure a safe and sustainable industry for the public.
There were safety concerns that non-commercial balloon pilots - which was not the case here - could take non-paying passengers for a balloon flight without any prescribed training, knowledge or medical certificate.
The report comes after an urgent safety review of commercial balloon operators following the tragedy.
The victims were: Masterton: Pilot Lance Hopping, 53; Valerie Bennett, 70; Husband and wife Desmond and Ann Dean, aged 70 and 65. Wellington: Ms Bennett's cousin Denise Dellabarca, 58; Husband and wife Howard and Diana Cox, aged 71 and 63. Lower Hutt couple Stephen Hopkirk, 50, and Belinda Harter, 49. Couple Chrisjan Jordann, 21, and Alexis Still, 19.
