What happened
During the initial takeoff phase of a scheduled crew training mission at Auckland International Airport in New Zealand, an aircraft experienced a critical loss of control. The flight departed at 15:59 NZST with five crew members on board the flight deck. Shortly after the aircraft rotated, the starboard wing lost lift, preventing the plane from achieving its intended climb rate and causing it to side-slip toward the runway centerline.
The aircraft's wingtip made contact with the ground, leading to a clockwise cartwheel motion around the nose radome. This sequence caused the structural disintegration of the airframe. The primary impact occurred approximately 3,865 feet past the threshold of runway 23, positioned 97.5 feet to the starboard side of the active runway. The accident resulted in two fatalities and three injuries. The aircraft was a total loss.
Findings
Investigations determined that the accident was triggered by the accidental engagement of reverse thrust during a simulated engine failure procedure. During the training maneuver, the rapid rearward movement of the power lever created an inertial force that caused the thrust brake lever to move into the reverse idle detent for the number 4 engine.
Because of this unintended reverse thrust, the aircraft was unable to reach the minimum control speed necessary to counteract the resulting thrust imbalance. This led to an uncontrollable roll and side-slip. By the time the crew identified and corrected the thrust asymmetry, the aircraft lacked the necessary altitude and time to recover from its unstable flight path before impacting the ground.