What happened
On the afternoon of 15 December 2004, a Cessna 172N, registration ZK-JES, was conducting a scenic flight from Kerikeri to Waitiki Airstrip. The flight began in favorable weather, but as the aircraft progressed along the coast, the pilot encountered a band of poor weather ahead. Seeking better conditions, the pilot attempted to navigate via the east coast.
As the flight continued, the weather deteriorated with extreme speed. A fast-moving frontal system caused the ambient air temperature to drop, meeting an unusually high dew point. This resulted in the sudden formation of low cloud, mist, and fog. The pilot found himself unable to maintain visual flight rules (VFR) and was unable to reach the planned alternate at Kaitaia or return to Kerikxi. After realizing that visibility was too poor to safely land on the nearby beach at Coopers Beach, the pilot elected to ditch the aircraft in the sea near Cable Bay.
The impact caused the aircraft to break into several sections. While the pilot and one passenger survived with serious injuries, a second passenger tragically drowned after being trapped in the wreckage.
The investigation
Investigators examined the meteorological conditions and the pilot's decision-making process. The investigation established that the pilot was appropriately licensed and the aircraft was well-maintained. While the pilot made a correct initial decision to turn back when encountering bad weather, the speed of the subsequent deterioration meant that by the time the pilot attempted to find a landing site, his options had been exhausted.
Analysis showed that the pilot had passed the point where a safe diversion to Kaitaia or a return to Kerikeri was possible. Furthermore, the investigation noted that the pilot had not briefed the passengers on using life jackets prior to the ditching, leaving them with insufficient time to prepare once the emergency became inevitable.
Findings
- The pilot was caught in rapidly deteriorating weather that prevented any further diversion to an alternate or departure aerodrome.
- Low cloud and mist formed almost instantly because the air temperature dropped to match the high dew point.
- The pilot's ability to make a timely decision was hindered by a lack of warning regarding the potential for such sudden changes.
- The operator did not fully utilize all available meteorological data, specifically failing to note the narrow spread between air temperature and dew point, which serves as a critical warning for cloud formation.
Safety action
Following the accident, a safety recommendation was issued to the operator to ensure full use of all available meteorological information to identify conditions that could lead to marginal or unsuitable flight environments.