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Final report

Summary

What happened

On 8 March 2013, the flight crew of a Qantas Airways Limited (Qantas) A330 aircraft, registered VH-EBV, was conducting a visual approach to Melbourne Airport, Victoria. The captain was the pilot flying with autopilot engaged.

Soon after being cleared for the approach, on descent through 3,000 ft, the captain set an altitude target of 1,000 ft in the autoflight system and selected the landing gear down, the first stage of wing flap and 180 kt as the target speed. The descent was continued in autoflight open descent mode and reached a maximum of 2,200 ft/min. As the aircraft was descending through about 1,800 ft the first officer advised the captain that they were low. The captain reduced the rate of descent by selecting autoflight vertical speed mode but a short time later the enhanced ground proximity warning system (EGPWS) provided ‘TERRAIN’ alerts followed by ‘PULL UP’ warnings. The crew carried out an EGPWS recovery manoeuvre and subsequently landed via an instrument approach.

At the time of the EGPWS alert the aircraft had descended to 1,400 ft, which in that area was 600 ft above ground level, with 9 NM (17 km) to run to touchdown. This was 100 ft below the control area lower limit and 1,900 ft below a normal 3° descent profile.

What the ATSB found

The ATSB found that during the visual approach the captain’s performance capability was probably reduced due to the combined effects of disrupted and restricted sleep, a limited recent food intake and a cold/virus. The captain assessed the aircraft’s flight path using glide slope indications that were not valid. This resulted in an incorrect assessment that the aircraft was above the nominal descent profile.

In addition, the combination of the selection of an ineffective altitude target while using the autoflight open descent mode and ineffective monitoring of the aircraft’s flight path resulted in a significant deviation below the nominal descent profile. The flight crew’s action in reducing the aircraft's rate of descent following their comprehension of the altitude deviation did not prevent the aircraft descending outside controlled airspace and the activation of the EGPWS.

The ATSB also identified that limited guidance was provided by Qantas on the conduct of a visual approach and the associated briefing required to ensure flight crew had a shared understanding of the intended approach.

What's been done as a result

In response to this occurrence Qantas updated their training material for visual approaches and enhanced similar material in their captain/first officer conversion/promotion training books. In addition, targeted questions were developed that required check pilot signoff for proficiency. Finally, visual approaches were included as a discussion subject during flight crew route checks for the period 2013–2015.

Safety message

The ATSB reminds operators and flight crew of the importance of continuous attention to the appropriateness of the autoflight system modes in use. Equally, the ATSB stresses the importance of continually monitoring descent profiles, irrespective of the type of approach being flown and the level of automation being used. For flight crew, this occurrence illustrates the need to communicate their intentions and actions to ensure a shared understanding of the intended approach.

 

The occurrence

Context

Safety analysis

Findings

Safety issues and actions

Sources and submissions

Appendices

 
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