On 18 September 2008, a Boeing Company 717-200 (717), registered VH-NXE, was being operated on a scheduled passenger flight from Cairns, Queensland to Alice Springs, Northern Territory. There were 70 passengers, four cabin crew and two flight crew on board. During the manually-flown visual approach by the pilot in command (PIC) to runway 30 at Alice Springs Aerodrome, the stickshaker activated. The pilot flying lowered the nose while continuing the turn onto final. The stickshaker activated again before the flight crew stabilised the approach to within the operator's criteria and landed without further incident.
The investigation found that the stickshaker activated because of a combination of bank angle, high nose-up pitch change rate and airspeed slightly below the approach speed. The aircraft was higher, faster and closer to the aerodrome than was suitable for the direct-to-final approach being attempted. The autothrottle was inadvertently not engaged by the flight crew after the automatic flight system was disconnected earlier in the approach, which contributed to the airspeed reduction. The PIC's response to the stickshaker did not conform to the aircraft manufacturer's procedures.
The investigation also found that the PIC's judgement and monitoring ability were probably adversely affected by personal and work stress and associated fatigue, although the duty roster met the necessary standards. Pilots operating within flight and duty time limitations can still experience fatigue. Responsibility for adequate flight crew wellbeing before flight rests with both operators and their pilots.
The investigation did not identify any organisational or systemic issues that might adversely affect the future safety of aviation operations. However, in response to this occurrence, the operator proactively issued a number of notices to pilots to enhance pilot flight mode annunciator and auto mode awareness in the 717, to highlight the aircraft's buffet protection system and to discuss recent stickshaker events, and to describe the stall recovery procedure in the 717. In addition, the operator amended a number of its command upgrade and recurrent simulator training requirements and worked with the aircraft manufacturer to reduce the incidence of stickshaker events across the operator's 717 fleet.
Preliminary Report Released 25 November 2008
On 18 September 2008, a Boeing Company 717-200 aircraft, registered VH-NXE, was being operated on a scheduled passenger service from Cairns, Qld, to Alice Springs, NT, with six crew and 70 passengers. During a visual approach to runway 30 at Alice Springs Airport, the pilot in command reported that the aircraft stick shaker momentarily activated during the final turn to the runway. The crew completed the landing and taxied the aircraft to the terminal without further incident.
|Date:||18 September 2008||Investigation status:||Completed|
|Time:||1309 CST||Investigation level:||Systemic - click for an explanation of investigation levels|
|State:||Northern Territory||Occurrence type:||Stall warning|
|Release date:||10 March 2011||Occurrence category:||Serious Incident|
|Report status:||Final||Highest injury level:||None|
|Aircraft manufacturer||The Boeing Company|
|Type of operation||Air Transport High Capacity|
|Damage to aircraft||Nil|
|Departure point||Cairns, Qld|
|Destination||Alice Springs, NT|