On 7 February 2008, a Boeing 717-200 being operated by Australian airline National Jet on a scheduled passenger service from Nhulunbuy (Gove) to Darwin flew an unstabilised night visual approach at the destination and made a very hard landing. The landing roll was completed and the aircraft taxied to the terminal. None of the 94 occupants were injured but the aircraft was suffered substantial structural damage and damage to the left hand main landing gear.
The accident was investigated by the ATSB. It was established that the First Officer was PF for the approach and that although ATC had issued clearance to fly a visual approach to Runway 29 at Darwin in light winds, the crew had elected to follow the Instrument Landing System (ILS). The aircraft commander recalled that the runway had been in sight before the aircraft passed over the Howard Springs NDB which was 9.3nm from the runway threshold.
Flight Data Recorder (FDR) data indicated that the this NDB was over flown at 3,100 feet QNH at 220 knots with the autopilot engaged which meant that the aircraft was above the ILS GS at that time. The First Officer reported attempting to capture the ILS GS from above using the Flight Director ‘VS’ mode and FDR data shows a rate of descent of up to 1600 fpm with airspeed at around 210 knots. The aircraft remained above the GS and, at a height of 1900 feet and a rate of descent of 1900 fpm, the First Officer disconnected the autopilot. Shortly after this the Outer Marker was passed with the aircraft in landing configuration and the ILS GS was captured at 1200 feet, but for most of the remainder of the approach was then flown slightly below it. At about 700 feet, the aircraft passed through a light rain shower but the runway lighting and Visual Approach Slope Indicator Systems remained visible.
Approaching 200 feet agl, the rate of descent again increased and the aircraft commander called ‘Sink Rate’ in accordance with the aircraft operator’s standard operating procedures. In response the First Officer increased the nose-up pitch attitude. However, just before touchdown rate of descent again increased and at 33 feet agl, with a rate of descent of nearly 1000 fpm, the FDR recording showed that an abrupt, nose-up movement of the command had been` applied to the control column and the auto throttle retarded the engine thrust to Flight Idle. The aircraft touched down within 300metres of the runway threshold and to the left of the centerline with a recorded vertical force of 3.6 g. The aircraft commander took control of the aircraft during the landing roll and taxied the aircraft to the terminal.
The investigation identified a number of relevant safety factors, including the flight crew's actions and control inputs, the aircraft operator's stabilised approach criteria and operational documentation, and the visual cues associated with runway 11/29 at Darwin Airport.
It was also considered that “there was no clear division of responsibilities between the aircraft operator and the third party training provider in regard to ensuring the standards of flight training met all of the operator’s requirements, which had the potential to reduce training effectiveness” and noted that “there was no provision in the current Civil Aviation Safety Authority regulations or orders regarding third party flight crew training providers, with the effect that the responsibility for training outcomes was unclear”. As a result of these observations, the aircraft operator implemented a number of safety actions in relation to enhancing their stabilised approach criteria and pilot training, the monitoring of third party training providers, and the amendment of relevant operational documentation. In addition, the Civil Aviation Safety Authority undertook to prioritise the completion of proposed legislation in relation to third party training providers.
The Final Report of the Investigation was released on 14 May 2010 and may be seen at SKYbrary bookshelf: Aviation Occurrence Investigation AO-2008-007 Final
No Safety Recommendations were made.