What happened
On the evening of 17 December 2002, a Piper PA31-325 Navajo, registration ZK-TZC, departed Feilding Aerodrome for a routine visual flight rules trip to Paraparaumu. On board were the pilot and his two young sons. Shortly after climbing to 1,000 feet near Palmerston North Aerodrome, the aircraft experienced an engine issue, resulting in the left propeller feathering.
In an attempt to return to Feilding, the pilot flew an irregular, low-altitude circuit. During a left-hand turn on the downwind leg for runway 10, the aircraft—configured with extended flaps and undercarriage—suffered a loss of control. The aircraft rotated away from the airfield and struck the ground in a near-vertical, nose-first attitude. The impact resulted in 3 fatalities.
The investigation
Investigators examined the flight path using radar data and interviewed several witnesses near the aerodrome. Radar plots revealed that after the initial engine issue, the aircraft descended rapidly to approximately 400 feet above mean sea level. Witnesses observed the aircraft flying at a very low altitude and noted that the left engine appeared to be non-functional, while the right engine was operating at high power.
One witness specifically noted the aircraft's undercarriage was extended and then retracted during the approach. The investigation also reviewed the pilot's training records, noting he had recently completed a multi-engine conversion and had demonstrated a good technical understanding of high-performance aircraft. The aircraft itself was found to have been properly maintained and airworthy prior to the flight.
Findings
- The primary cause of the accident was the pilot's decision to fly an improper and improbable landing circuit while managing an engine-out situation.
- The aircraft's airspeed likely decayed below the minimum single-engine control speed during a low-altitude turn, leading to an uncontrollable yaw and roll toward the dead engine.
- The pilot's decision-making during the emergency was inconsistent with his training and failed to utilize safer, more logical landing options.
- While the left propeller was found to be feathered, no definitive reason was identified for why the engine power loss occurred.
- The use of high-drag configurations (extended flaps and gear) at a low altitude exacerbated the loss of lift and airspeed.