The cockpit data recorder on the Lulutai airlines Saab340B which lost its brakes and hit a concrete wall after landing at Fua’amotu airport was not working properly.
A preliminary report from the investigation into the crash organised by the Ministry for Infrastructure’s civil aviation department said the flight data recorder did not contain any information about the aircraft’s progress before the crash.
It said the recorder indicated that it last worked properly on July 11, 2023.
There were signs that the recorder may have been deliberately disabled.
The cockpit voice recorder was working, but the cockpit microphone appeared to have been operating at a very low level. The underwater locator beacon had not been fitted.
The aircraft was en route to from Fua’amotu to Lupepau’u airport in Vava’u on December 8, 2023.
The aircraft was carrying three crew and 35 passengers.
About 1pm the crew began their descent. While passing through 8000 feet the crew noticed that the hydraulic system was showing empty, despite the earning lights not being active.
The hydraulic panel showed zero pressure, zero pressure in the main hydraulic accumulator and zero pressure in the inboard brake accumulator pressure.
As a result, the crew decided to return to Fua’amotu, which had a longer runway and maintenance services. Once notified that the flight was returning, rescue and fire services and His Majesty’s armed Forces went on standby.
About 54 nautical miles from Fua’amotu the crew lowered the undercarriage using the emergency hydraulic pump. However, the crew were unable to lower the flaps.
The aircraft was able to taxi after it landed, but the brakes failed and it ran off the apron and hit a low concrete wall, which caused the right undercarriage to collapse. The passengers were evacuated with no injuries, although reports at the time said one man was carried off the aeroplane.
The accident investigation said that the licensed engineers responsible for the Saab had visited the aircraft after the crash, but had not reported any visible hydraulic leaks.
After the aircraft was stabilised on hydraulic jacks, it was examined by the accident investigation team. Apart from the right undercarriage leg, a propellor was damaged and the nosewheel had rotated about 180 degrees.
Further investigation found several cracked hydraulic pipes. The accident report said the damage was likely associated with the accident.
The investigation is continuing. It will include further examination of the cockpit voice recorder, the electrical system for the data recorder and aircraft maintenance documentation.
