What happened
On 29 September 2009, a Piper PA32-260 (registration ZK-CNS) departed Great Barrier Aerodrome for a scheduled flight to Auckland International Airport. The aircraft, operated by Great Barrier Airlines, was carrying a pilot and five passengers. The flight was operating near the aircraft's maximum authorized takeoff weight.
During the takeoff roll on runway 28, the aircraft performed normally and lifted off approximately halfway down the runway. However, shortly after rotation, the aircraft failed to maintain its expected climb rate. The pilot, attempting to accelerate the aircraft to climb speed, retracted the flaps prematurely. Simultaneously, the aircraft encountered a sudden change in wind direction that likely introduced a tailwind component.
As the aircraft struggled to gain altitude, the pilot attempted a shallow left turn toward a swampy area to avoid rising terrain and trees. This maneuver further reduced performance, causing the aircraft to strike vegetation and eventually cartwheel into a swamp roughly 700 meters from the runway end. The impact resulted in moderate injuries to the pilot and one passenger, while the remaining four occupants sustained minor injuries. The aircraft was destroyed.
The investigation
TAIC investigators examined the aircraft's maintenance records, the pilot's experience, and the meteorological conditions at the time of the accident. The investigation confirmed that the ZK-CNS was mechanically sound and the pilot was appropriately licensed and experienced for the flight.
Investigators analyzed the weight and balance, noting the aircraft was operating near its maximum takeoff weight. They also reviewed the wind conditions, which were characterized by gusty, shifting winds. The investigation focused on the sequence of aerodynamic changes occurring immediately after the aircraft left ground effect, specifically how the combination of weight, wind shear, and pilot actions affected the climb gradient.