What happened
On the afternoon of 27 March 1999, a Fletcher FU2SB-954, registration ZK-EMV, was performing routine agricultural sowing operations near Riversdale in the Wairarapa. After completing several successful runs, the pilot requested an increased load of 23 hundredweight of superphosphate for the final flight of the session.
As the aircraft departed from the grass airstrip, it experienced a rapid descent. Witnesses observed the aircraft appearing to drop significantly after leaving the ground. While in a high-nose attitude, the aircraft struck a fence located near a road. The impact caused the aircraft to balloon upward and roll into an inverted position, eventually striking the ground with massive force. The impact destroyed the aircraft and caused the death of the pilot.
The investigation
The investigation examined the aircraft's mechanical condition, the weather, and the sequence of the flight. Testing of the engine and propeller confirmed that the aircraft was performing normally and was capable of producing full power at the time of the accident. There was no evidence of mechanical failure or control system defects prior to the initial impact with the fence.
Investigators also analyzed the environmental conditions and the aircraft's weight. The investigation noted that the aircraft was operating at a heavier load than previous runs that day. The topography of the site, which featured a sudden drop in elevation at the end of the strip, was also examined alongside the meteorological data, which showed a light tailwind and increasing temperatures.
Findings
Several contributing factors led to the accident:
- The aircraft was likely overweight for the specific weather conditions present during the final takeoff.
- A light tailwind component reduced the aircraft's takeoff and departure performance.
- The loss of ground effect immediately after leaving the airstrip, combined with a possible area of sink, prevented a positive climb gradient.
- The pilot's decision to jettison the load was too late to avoid the fence strike.
- The impact with the fence caused structural damage to the wing and tailplane, rendering the aircraft uncontrollable.