A late switch from autopilot to manual control due to heavy rain likely contributed to an Air New Zealand flight veering off the runway when landing at Auckland Airport.
A recently released Transport Accident Investigation Commission report looked into the incident – in which there were no injuries – that occurred on January 27, 2023 – the night of the Auckland Anniversary floods.
It found the veer-off likely happened because heavy rain had contributed to a late transition from autopilot to manual control.
“The timing of the autopilot disengagement combined with the technique used by the pilot flying, very likely resulted in there being insufficient time to correct the flightpath of the aeroplane before landing,” the TAIC report said.
“The pilot flying was therefore unable to prevent the aeroplane drifting away from the centreline before landing and stop it veering off the runway after landing.”
TZK-OKN, a Boeing 777, was on a scheduled flight from Melbourne to Auckland.
On approach, the flight encountered heavy rain and wind, which changed in direction and strength.
As the aircraft neared the runway, it began to drift right of the centreline. Soon after touchdown, it “veered” off the runway onto a sealed shoulder, striking six runway edge lights along the way.
The pilot regained control and taxied the aircraft to the airport terminal. Nobody was injured.
An inspection of the aircraft found six of the right landing gear tyres were damaged, with one deflated. The right brake assembly and wiring harness also suffered damage.
According to the report, the autopilot was disengaged at 20 metres, when operator procedures suggested it should occur at between 90 and 180 metres.
“The late disengagement was likely because of the inclement weather on the approach,” the report’s findings said.
“When the autopilot was disengaged, the autopilot control inputs ceased, and the flight and pilot controls returned to a neutral position. This resulted in the aircraft rolling to the right and drifting right of the centreline.
“It is very likely that the pilot flying did not hold the same control inputs set by the autopilot when they disengaged the autopilot.”
The weather, while bad, had not met the minimum weather requirements throughout the approach and landing, and the commission said it was “exceptionally unlikely” that water on the runway caused the incident.
The commission found the approach and landing briefing did not meet the operator’s guidelines – although it was exceptionally unlikely it contributed to the incident.
Since the incident, Air New Zealand has amended its operational procedures and information and has provided training to reinforce the technique for a smooth transition from autopilot to manual control.
In a statement to 1News, the airline acknowledged the report and praised its staff for how they handled themselves during the incident.
“The incident occurred during the onset of a severe weather event that caused widespread flooding in Auckland, and we recognise our crew for their professionalism in managing the aircraft under unexpected and challenging conditions,” chief safety and risk officer Nathan McGraw said.
“Our own investigation, conducted alongside the Commission’s work, has led to safety enhancements, as referenced in the report.
“We remain committed to continuously improving our training and operational procedures to uphold the highest standards of safety.”
