Plane's centre of gravity can shift, crash report says

The scene of the fatal crash. Photo / Sarah Ivey

A plane that crashed near Fox Glacier killing all nine people on board is believed to have been over its maximum allowable weight and off-balance.

None of the passengers on board were secured.

An Interim Factual Report released by the Transport Accident Investigation Commission (TAIC) today describes the final moments before a Skydive NZ ZK-EUF lost control and crashed into a field on September 4.


Click here for the full report.

The TAIC issued two urgent recommendations to the Director of Civil Aviation in its report.

It asked the director to alert all pilots of Fletcher FU24-954 aircraft that the plane's centre of gravity can shift aft in parachuting operations involving six or more people.

A second recommendation asked for the Flight Manual to offer more accurate determinations of the aircraft's centre of gravity.

The TAIC estimated in its report that the small plane was five kilograms over its maximum certified limit of 2203kg going into the fatal Fox Glacier flight.

It also determined the plane's centre of gravity was 0.115m outside the allowable aft limit of 0.645m.

It said none of the crew members or parachutists on board were attached to the aircraft.

Witnesses reported the plane took-off normally before pitching upward until almost vertical.

The plane then performed a "wing-over" and plunged vertically to the ground, the TAIC said.

Several people witnessed a mist or vapour encase the aircraft on impact and immediately burst into flames.

Whether overloading or balance issues contributed to the plane's loss of control on take-off is yet to be determined.

The TAIC noted that its report contained no analysis or findings and said "any extrapolation of the information given in this report would be speculation".

TAIC investigator Ian McClelland said the overall weight of the plane was not so much an issue as the "position of that weight about the aircraft".

"We just identified that as an initial safety concern. We're not saying that's the cause of the accident. Until we do a more accurate weight and balance for the aircraft we can't say what effect that would have had on the ability of the pilot to control the aircraft."

"Obviously as the centre of gravity moves further aft it is going to increasingly restrict the pilot's ability to control the aircrfaft, till it reaches a point where it could not be controlled."

Restricting the number of passengers and making sure "they are seated well forward" would ensure an aircraft was within its centre of gravity limits.