KEY POINTS:
Spilled coffee has been identified as the cause of the smoke in an Air New Zealand Boeing 737 aircraft that had to be diverted, stranding 122 passengers, including 15 MPs.
The alternative transport arrangements some MPs made at the taxpayer's expense has already attracted media attention.
National MP
Judith Collins and three of her caucus colleagues took a $360 taxi ride from Ohakea back to Wellington.
While the National MPs made off in the taxi, Labour MPs were calling Transport Safety Minister Harry Duynhoven asking him to use his clout to arrange permission for a replacement aircraft to land at Ohakea.
It worked, and they eventually reached their destination.
Today the source of all the disruption in May last year was revealed in a report by the Transport Accident Investigation Commission. Wires in the cockpit short-circuited four hours after coffee was spilt on them.
"As the coffee dried, the sugar content provided sufficient conductivity to bring about a slow electrical breakdown, which resulted in spurious warning light indications, electrical burning of an avionics component and an eventual short circuit," the report said.
The aircraft was near Paraparaumu and climbing through about 6000 metres when a number of warning lights on the cockpit overhead panel went on.
The captain immediately stopped climbing the aircraft and handed over control to the first officer so he could diagnose the cause.
He consulted a quick reference manual which was of no help because of the number of lights.
He contacted maintenance staff for advice and it was mentioned that the problem could be linked to a fluid spill in the cockpit that afternoon.
The first officer began to smell what he though was electrical burning. A purser also smelled a strong electrical or plastic burning smell on entering the cockpit. She saw a slight haze but no smoke.
The first officer announced that there was smoke on the flight deck and donned smoke goggles and an oxygen mask. The captain smelled the burning and briefed the purser.
Shortly before 9pm the captain declared a state of urgency to air traffic control and requested a diversion to Ohakea for a precautionary landing.
As flight attendants prepared for landing they thought there was also a burning smell near the middle of the cabin. An off-duty 767 pilot seated in the exit row was briefed. He also detected the smell and offered to assist.
The captain took control of the aircraft for landing and there was some confusion about whether the landing gear was down. They sought visual verification from the ground controller.
The aircraft landed at 9.20pm, with the crew opting to taxi to disembark passengers normally as the burning smell had abated. No one was injured.
The coffee spill has been traced to a different crew preparing the aircraft at 4.45pm. As the first officer picked up his coffee cup the lid came off and some of the contents landed on him, the floor and the rear corner of the centre control pedestal.
- NZPA