ATSB Report re HS-TJW 4 Nov 2007

[Philip Argy]

This short segment of TJW's final approach to RWY 16 in MEL on 4 November 2007 could have turned nasty had visual ref not been established when it was:

1308:21
The landing reference speed of 142 kts was set on the MCP. The FDR indicated that the average rate of descent from 4,000 ft was 1,500 ft/min, with a maximum of 1,808 ft/min when the aircraft was at 8.5 DME (16 km). The aircraft descended below the 2,100 ft segment minimum altitude step at 6.8 DME (12 km).
1309:08
The aircraft was approximately 6.25 DME (7 km) and descending through 1,544 ft, which was 556 ft below the 2,100 ft segment minimum safe altitude. The aircraft descended below the clouds and, almost simultaneously, the EGPWS aural terrain alert, ‘CAUTION TERRAIN’, sounded for 4 seconds and the terrain display and the terrain caution message appeared on the navigation displays on the forward instrument panel for 15 seconds. The PIC and the relief pilot reported that they were both attempting to visually locate the runway. The copilot (PF) reported that his monitoring of the instruments was diverted to looking outside the aircraft in an attempt to locate the runway.
1309:18
A second EPGWS aural terrain alert ‘TOO LOW TERRAIN’ sounded for 4 seconds.
1309:20
The copilot disengaged the autopilot and initiated a pitch-up manoeuvre. The lowest altitude recorded during the manoeuvre was 1,247 ft, which was 513 ft above ground level (AGL). At about that time, the ADC in the air traffic control tower saw lights below the cloud base that appeared to be unusually low for an aircraft.
1309:30
After confirming the aircraft position on the air situation display, the ADC transmitted ‘…low altitude alert check your altitude immediately’ to the crew. The copilot reported that, after that transmission, he saw the runway and the PAPI. The PIC replied to the ADC ‘…okay have the runway in sight now’.

The copilot continued to fly the aircraft manually and climbed the aircraft to about 1,400 ft. The aircraft was held at that altitude until intercepting the PAPI 3° indication, which was then maintained until landing. The approach was stabilised by 500 ft above the runway.

ATSB findings:

FINDINGS
From the evidence available, the following findings are made with respect to the procedures-related event involving Boeing Company 777-2D7 (777) aircraft, registered HS-TJW, that occurred near Melbourne Airport, Vic. and should not be read as apportioning blame or liability to any particular organisation or individual.
Contributing safety factors
• The copilot was unsure of the descent clearance, which delayed further descent. This placed the aircraft above the flight management computer (FMC)-computed flightpath.
• The crew did not maintain awareness of the aircraft’s profile during the approach.
• The crew did not fly a 3° constant angle descent.
• The operator’s Continuous Descent Final Approach training had not been provided to the crew. [Safety issue]
• The crew did not conduct a ‘go-around’ as was required by the operator’s procedures when the aircraft was 1,000ft above terrain with a high rate of descent.
Other safety factors
• The pilots had not conducted a non-directional beacon (NDB) approach in an aircraft or simulator for 18 months.