Background
Air New Zealand Flight 4374 was a scheduled flight from Gisborne to Auckland, operated by an eight-year-old Fokker Friendship F27-500. The aircraft had previously been operated by the New Zealand National Airways Corporation (NAC) until the merger with Air New Zealand in 1977. It had accumulated 18,718 flight hours through 25,704 flight cycles. On the return leg from Gisborne Airport, the aircraft carried two engineers who had serviced another aircraft there. The flight crew consisted of 38-year-old Captain Anthony Circuitt and 33-year-old First Officer Barrie Moran.
Accident
At 14:28, the aircraft descended to 3,000 feet and the pilots deployed the flaps. The aircraft's speed was 165 knots, which increased to 211 knots. Two minutes and fourteen seconds later, the aircraft crashed into the harbour 1 kilometer west of the intended runway. At the time, Auckland was experiencing its heaviest rainfall in 43 years, and visibility was officially described as "restricted." The crash killed the captain and one passenger.
Rescue
Two survivors supported themselves on the tip of the aircraft fuselage and were rescued by navy divers using two rubber inflatable Zodiac boats. Rescue efforts were hindered by strong rips in the harbour. The survivors were taken to Middlemore Hospital. Captain Circuitt's body was freed by navy divers about 3.5 hours after the crash, while engineer John Forbes's body was recovered later that night. Auckland Airport's rescue hovercraft was undergoing an overhaul and was unavailable, further complicating rescue operations. The hovercraft had been known to be unreliable, prompting discussion on the airport's rescue capabilities and safety.
Investigation
The aircraft's flight recorders (black boxes) were recovered and sent to Melbourne for investigation by the Australian Ministry of Transport Air Safety Investigation Branch. The investigation determined that the crew were likely misled by a visual illusion caused by a rain shower obscuring the runway threshold during their base turn. This, combined with a failure to monitor their flight instruments effectively because the pilots believed they were at a safe height, led to the aircraft crashing into the harbour.
Aftermath
In the wake of the crash, discussions arose questioning Auckland Airport's safety. The airport's rescue hovercraft had been inoperable for a year, but the Minister of Transport stated that the airport met International Civil Aviation Organization (ICAO) safety requirements. According to the Auckland Star, only one inflatable boat was immediately usable because another had an unserviceable outboard motor. The Minister requested a report on the unserviceable motor. New Zealand Prime Minister Robert Muldoon assured the public that "if at any time and for whatever reason equipment and personnel are unable to meet those standards, the airport is closed for aircraft movements" and that the airport was complying with required standards at the time of the crash. A wind-measuring system was added at the end of the runway shortly after the accident. In October 1980, Labour Party spokesperson N.J. Jones announced the government's intention to introduce a special aviation tax to finance airport safety, citing that the crash indicated a need for improved safety levels.