Pilot error or mechanical failure were the most likely causes of a 2010 plane crash in New Zealand in which nine people died, a coroner found yesterday. The Fletcher FU24 crashed and burst into flames shortly after take-off on September 4, 2010, near the Fox Glacier on the west coast of New Zealand's South Island, in the nation's worst air accident since 1993. Operated by Skydive New Zealand, the plane was carrying a pilot, four skydiving instructors and four tourists, from Britain, Ireland, Germany and Australia. There were no survivors. Coroner Richard McElrea found the plane, a converted crop duster, was overloaded and off balance when it took off on a "near vertical" climb, then apparently stalled before crashing. "It is unlikely that the cause of the crash will ever be fully understood - something unusual, such as inadvertent pilot error or engine malfunction/mechanical failure, has occurred at take-off," he said. "This, coupled with the aircraft being overweight and loaded rearwards of its centre of gravity, is consistent with the evidence and has been the immediate cause of the tragedy." McElrea said eight bodies were found in the plane's tail section, raising the possibility that they slid backwards during the plane's ascent, throwing off its centre of gravity. He recommended fitting restraints on skydiving flights using the FU24 to prevent such movement and limiting the number of passengers to six. The families of the four tourists who perished released a letter to Prime Minister John Key calling for tighter enforcement of aviation regulations operating in New Zealand's adventure tourism industry. The families criticised what they said was a lack of accountability in the industry, pointing out that no one had been prosecuted over the accident.