What aircraft was involved and where did it happen?

The accident on 1999-03-18 involved a aircraft, at NZ.

What was the probable cause of the accident?

The specific cause of the engine failure remains unknown as the aircraft was not recovered; however, the sudden loss of power led to an emergency ditching where the rapid sinking of the aircraft prevented the use of onboard life-saving equipment.

Engine Failure Leads to Sea Ditching Near Pitt Island

A Cessna 206 experienced a sudden engine failure and ditched in the sea near Pitt Island, forcing all five occupants to swim to shore.

What happened

On 18 March 1999, a Cessna 206, registration ZK-DOA, was conducting an aerial surveillance flight near Pitt Island when the engine lost power without warning. The aircraft, operated by Air Chathams Limited, was flying at approximately 800 feet above mean sea level near Hakepa Hill when the failure occurred.

The pilot attempted to troubleshoot the issue by checking the fuel selector and circuit breakers, but the engine could not be restarted. Realizing the aircraft could not clear the coastline, the pilot executed an emergency ditching approximately 800 metres from the shore. Upon impact with the water, the aircraft nosed down, inverted, and sank rapidly. All five occupants—the pilot and four passengers—managed to escape the sinking wreckage. Due to the rapid sinking and the short 30-second window between the engine failure and impact, the occupants were unable to locate or don the life-jackets stored on board. The group spent roughly one hour swimming through the sea before reaching the shore, where they were assisted by local residents.

The investigation

The investigation focused on the sudden loss of power and the survival circumstances of the occupants. Because the Cessna 206 was not recovered from the ocean, investigators could not definitively determine the mechanical cause of the engine failure. However, there was no evidence of fuel contamination or improper maintenance. The investigation also examined the pilot's emergency response and the adequacy of passenger safety briefings.

Findings

The engine failed suddenly and without prior warning.
The cause of the engine failure was not established due to the loss of the aircraft.
The pilot's attempt to troubleshoot the engine was hindered by the extreme time constraints of the emergency.
While life-jackets were available on the aircraft, the passengers were not sufficiently informed of their location or how to use them.
The occupants' survival was aided by favorable weather and sea conditions, though the lack of life-jackets presented a significant risk.

Safety action

Following the incident, a safety recommendation was issued to the Civil Aviation Authority. The recommendation suggested amending aviation rules to require the wearing of life-jackets for occupants of single-engine aircraft when flying at low altitudes over water and outside gliding distance from land.