Great Barrier Airlines

At about 1300 on Sunday 5 July 2009, ZK-LOU, a 3-engined Britten Norman BN2A Mk III Trislander operated by Great Barrier Airlines (the company), took off from Great Barrier Aerodrome at Claris on Great Barrier Island on a regular service to Auckland International Airport. On board were 10 passengers and a pilot, all of whom were wearing their seat belts. That morning the pilot had flown a different Trislander from Auckland International Airport to Claris and swapped it for ZK-LOU for the return flight because it was needed for pilot training back in Auckland. Another company pilot had that morning flown ZK-LOU to Claris from North Shore Aerodrome. He had completed a full engine run-up for the first departure of the day, as was usual, and said he noticed nothing unusual with the aeroplane during the approximate 30-minute flight. For the return flight the pilot said he completed the normal after-start checks in ZK-LOU and noticed nothing abnormal. He did not do another full engine run-up because it was not required. He taxied the aeroplane to the start of sealed runway 28, applied full power while holding the aeroplane on brakes and rechecked that the engine gauges were indicating normally before starting the take-off roll. The aeroplane took off without incident, but the pilot said when it was climbing through about 500 feet he heard an unusual “pattering” sound. He also heard the propellers going out of synchronisation, so he attempted to resynchronise them with the propeller controls. He checked the engine’s gauges and noticed that the right engine manifold pressure and engine rotation speed had dropped, so he adjusted the engine and propeller controls to increase engine power. At that time there was a loud bang and he heard a passenger scream. Looking back to his right the pilot saw that the entire propeller assembly for the right engine was missing and that there was a lot of oil spray around the engine cowling. The pilot turned the aeroplane left and completed the engine failure and shutdown checks. He transmitted a distress call on the local area frequency and asked the other company pilot, who was airborne behind him, to alert the local company office that he was returning to Claris. The company office manager and other company pilot noticed nothing unusual with ZK-LOU as it taxied and took off. The other pilot was not concerned until he saw what looked like white smoke and debris emanate from the aeroplane as though it had struck a flock of birds. Despite the failure, ZK-LOU continued to climb, so the pilot said he levelled at about 800 feet and reduced power on the 2 serviceable engines, completed a left turn and crossed over the aerodrome and positioned right downwind for runway 28. There was quite a strong headwind for the landing, so the pilot elected to do a flapless landing and keep the power and speed up a little because of the possibility of some wind shear. The pilot and other personnel said that the cloud was scattered at about 2500 feet, that there were a few showers in the area and that the wind was about 15 to 20 knots along runway 28. The visibility was reported as good. After landing, the pilot stopped the aeroplane on the runway and checked on the passengers before taxiing to the apron. At the apron he shut down the other engines and helped the passengers to the terminal, where they were offered drinks. The company chief executive, who lived locally, and a local doctor attended to the passengers. Three of the passengers received some minor abrasions and scrapes from shattered Perspex and broken interior lining when the propeller struck the side of the fuselage.

On Friday 20 July 2001, at around 0450, Partenavia P68B ZK-DMA was abeam North Shore Aerodrome at 5000 feet in darkness and enroute to Whangarei, when it suffered a double engine power loss. The pilot made an emergency landing on runway 21 at North Shore Aerodrome, but the aircraft overran the end of the runway, went through a fence, crossed a road and stopped in another fence. The pilot was the only person on board the aircraft and received face and ankle injuries. The aircraft encountered meteorological conditions conducive to engine intake icing, and ice, hail or sleet probably blocked the engine air intakes. The pilot had probably developed a mindset that dismissed icing as a cause, and consequently omitted to use alternate engine intake air, which should have restored engine power.

The aircraft departed overweight for a 17-hour ferry flight. Early in the flight the crew experienced some fuel problems and decided to continue when they resolved the problem. The crew indicated the en route winds were close to forecast. The ferry fuel system is a simple 5- tank gravity fuel feed into the fore and aft main tanks. About 6 hours from destination, they realized the ferry tanks were not flowing into the main tanks as planned. They began manually transferring fuel from the rear ferry tank to the forward ferry tank, and shut down the right engine to reduce fuel consumption. This did not stop the negative fuel flow from the main tanks. At the time of ditching, the crew estimated the fuel remaining in the ferry tanks was about 170 gallons, most of which was in the 3 aft ferry tanks. An aero engineer calculated that the aircraft was at least 10 inches behind the maximum aft cg at the time of ditching, and suggested that the ferry fuel system was not managed to maintain the cg within the allowable limits, a task made more difficult with the rear fuselage cargo.