A helicopter transferring a patient between Ashburton and Christchurch in 2014 was forced to make an emergency landing without power onto farmland when it lost power to both engines.
None of the four people on board was injured and there was only minor damage to the helicopter during the night-time landing on a farm near Springston on May 5, an inquiry has found.
A Transport Accident Investigation Commission report said the BK117 lost power because of pilot error. He had not flown that kind of aircraft for five years, so did not switch on the fuel transfer pumps after starting the engines. This starved the engines of fuel despite the tank being full.
"The pilot did not refer to a checklist when carrying out the normal pre-flight, before-start and after-start procedures. Had he referred to a checklist he would have likely corrected the error in the fuel system configuration before flight."
The report said the company that operated the helicopter, Garden City Helicopters, had no procedures in place to address the lack of recent experience, such as additional training, supervision or a policy on the use of written checklists in such a situation.
As well, a cockpit lighting modification meant the pilot couldn't see the "brightly illuminated caution lights" that would have alerted him to the low fuel levels in the supply tanks and could have prevented the crash.
The commission said the key lessons from the inquiry were:
• pilots who lack recent experience on an aircraft type should refer to written cockpit checklists when carrying out normal and emergency procedures
• pilots who fly multiple aircraft types must remain vigilant to inadvertently transferring habits and procedures from one type to another
• operators who require pilots to fly different aircraft types must have robust policies and procedures that ensure the pilots are appropriately experienced, trained and current on each aircraft type.