What happened
On October 29, 2011, an Air New Zealand Boeing 737 was operating a scheduled flight from Auckland to Christchurch carrying 128 passengers and six crew members. The flight deck included the captain, the first officer, and a check captain who was performing an annual route check on the captain.
While weather conditions at the departure point were favorable, visibility at Christchurch significantly degraded during the flight due to fog and low cloud cover. As the aircraft performed a standard instrument approach from the south, it reached the decision height of 200 feet. At this altitude, pilots are required to have sufficient visual reference to the runway; if the runway lights are not visible, a missed approach must be initiated.
On this occasion, the aircraft remained obscured by fog at the 200-foot threshold. The captain did not begin a go-around procedure. The runway approach lights only became visible once the aircraft had descended to approximately 100 feet, at which point the captain continued the descent to land.
The investigation
The investigation focused on why the mandatory missed approach was not performed and why the crew did not intervene. Investigators examined the cockpit dynamics, noting that the captain had failed to respond to two procedural check calls prior to reaching the decision height. Furthermore, the investigation looked into the psychological state of the pilot flying and the impact of having a check captain present on the flight deck.
Findings
The captain's failure to initiate a missed approach was driven by significant personal and situational stress. The investigation identified three primary contributing factors to this stress: the recent impact of the Canterbury earthquakes and their aftershocks, the pilot's personal health issues, and the anxiety related to undergoing a route check.
Additionally, the investigation found that the first officer failed to challenge the captain's lack of response to the two procedural check calls. The presence of a check captain was also noted as a factor that could potentially influence crew interaction and dynamics.