737 Descent below Instrument Approach Minima – HF Lessons
Human factors are discussed in the report into an incident in New Zealand.
Using the autopilot, the aircraft descended on the glideslope but at decision height (200 feet Above Ground Level) the aircraft was still in cloud and the runway or approach lights were not visible. The captain however did not initiate a go-around, but just as first officer and check captain were about to intervene, the approach lights became visible at about 100 feet AGL and the captain continued for a safe landing.
On 26 June 2014, the New Zealand Transport Accident Investigation Commission (TAIC) issued their report into this incident with an Air New Zealand Boeing 737-300, registration ZK-NGH in Christchurch on 29 October 2011. Crew:
- Captain (Pilot Flying): 68, ATPL, 23,875 hours total, 7,210 hours on type
- FO: (Pilot Monitoring): 43, ATPL, 8,420 hours total, 2,320 hours on type
- Check Captain: 49, ATPL, 17,200 hours total, 9,200 hours on type
The weather forecast for Christchurch indicated broken cloud ceiling at 1200 feet, rain, visibility of 1500 meters reducing to 200 meters in rain. As the aircraft approached the airport was reporting overcast cloud at 300 feet, runway wet, winds from 020 degrees at 6 knots, visibility of 6000 meters reducing to 2000 meters TAIC state:
A pilot not initiating a missed approach when they do not have the required visual reference at decision height is a safety issue. Before reaching the decision height, the captain had failed to respond to two other procedural check calls, and these two failures went unchallenged by the first officer, which is another safety issue.
…the captain did not comply fully with the procedures and perform the mandatory missed approach because he was under stress brought on by a combination of factors comprising: the Canterbury earthquakes and their aftershocks, personal health issues and anxiety associated with the route check flight.
The captain’s communication style could have been described as minimalistic – not wishing to promote interactive communication. He had a reported reputation within the company for saying little on the flight deck, and the first officer was aware of that reputation. The captain’s communication style and his reputation could well have contributed to the observed breakdown in the communication loop during the approach to Christchurch. It could also explain why the first officer was unwilling to challenge the lack of response to the 1000-feet call..
In this case the first officer should have challenged the captain on two occasions for not making the correct response to the automatic calls generated by the aeroplane systems. The first officer was aware that the captain was being assessed, but he said that this was not an issue as far as he was concerned. However, the psychologist was of the opinion that any first officer faced with the captain’s uncommunicative style, in a similar situation could have found themselves having to determine the boundaries of their involvement. Stepping in too early to take corrective action or waiting too long for the captain to respond to a call may have been resented by the captain or seen by the check captain as interfering with the check process. In other words, because the two pilots were meant to act as a team, the first officer’s performance could be perceived as affecting the assessment of the captain’s performance.
The captain, on each occasion on which he was reported, acknowledged his error but continued with his normal way of operating. The operator had a responsibility to ensure that its pilots were complying with its procedures. Standardisation is essential for safe airline operations. This is especially so where there are a large number of pilots, and where first officers rarely team up with the same captains. The operator’s standard procedures and regular crew resource management training are designed with this in mind. As a result of the incident the operator developed a performance management plan for the captain, but he retired before it could be put into action.
The captain did not make the appropriate response to two automated calls prior to the aeroplane reaching the point (decision height) at which the flight crew needed to decide whether to continue and land, or initiate a missed approach, and the first officer did not challenge the captain for an appropriate response on either occasion.
- The captain compromised the safety of the flight by not initiating a missed approach when the aeroplane reached the decision height and the meteorological conditions were not suitable to land.
- The only appropriate decision was for the captain to commence a missed approach. He did not make that decision probably because he was operating under a level of stress, where anxiety was interfering with his cognitive functioning.
- There was no evidence to suggest that the pilot’s age was a factor affecting his performance on the flight.
- The presence of the check captain on the flight deck and its effect on crew dynamics and communications had not been thoroughly discussed during the pre-flight briefing, which had the potential to blur the boundaries of individual involvement in the flight deck operations.
- The operator had not followed its own procedures for managing the previously identified performance issues with the captain. This resulted in his continuing with non-conforming practices, virtually unchallenged.
Air New Zealand (the operator) has used this incident to reinforce to its pilots the need to follow standard operating procedures and initiated a range of other safety actions. A recommendation was made to the Director of the Civil Aviation to highlight to other operators the need to follow procedures and to appropriately manage those situations where the normal crew dynamics may be disrupted by the inclusion of additional personnel, for example during a check flight.