Fatigue cracks missed during an engine overhaul caused an Air New Zealand turboprop engine to catch fire on approach to Wellington, with the ensuing evacuation taking twice as long as it should have done, an investigation has found.
The ATR72-600 was flying from Christchurch to Wellington on September 1, 2024, with 70 passengers and four crew on board when its left engine caught fire shortly before landing.
The plane landed safely, stopped on the runway and crew then discharged fire suppressant, but fire warnings stayed on and the captain ordered an evacuation.
The Transport Accident Investigation Commission's (TAIC) final report, released today, found the evacuation took 2 minutes and 51 seconds. The benchmark is 1 minute and 30 seconds, with a longer evacuation increasing the risk to life.
Some passengers received minor injuries while getting off the aircraft. Several who left through the forward-left exit walked near the engine that had been on fire. Nearly half of passengers took their carry-on baggage with them when evacuating the aircraft.
Other passengers were surprised by the size of the forward exits and had trouble using them, including having to step onto the bottom lip of the door and then jump nearly 2m to the ground.
Air New Zealand today acknowledged the evacuation "took longer than we would want" and has made changes to training, procedures and passenger safety information.
Clear evacuation procedures
TAIC chief investigator of accidents Louise Cook said the report highlighted the importance of clear evacuation procedures.
"The crew landed safely and everyone got off the aircraft. But an emergency response doesn’t end when an aircraft reaches the runway. Evacuation is critical, and this incident shows why crew need clear, well-practised procedures and passengers need to understand instructions … and follow them."
'Rare but serious': Cracks missed in inspection
The report found the fire started when a low-pressure turbine blade failed due to fatigue. Oil leaked into the engine, causing smoke and flames that set off the fire warning.
The engine had been overhauled shortly before the incident, but the fatigue cracking was not picked up during quality assurance checks. A second blade from the same engine also showed signs of fatigue.
Cook described this as a "rare but serious technical failure".
The incident occurred as the plane landed just after 4pm (Source: 1News)
"It shows why maintenance assurance processes need to be strong enough to detect signs of fatigue before components return to service."
TAIC has recommended engine manufacturer Pratt & Whitney Canada strengthen its overhaul quality assurance procedures so pre-existing fatigue can be identified.
Changes for Air NZ
The commission found several factors slowed the evacuation. It has recommended Air NZ find ways to improve passenger briefings, safety cards and crew training, including clear instructions on what passengers should do once outside the plane.
Cook said TAIC welcomed the airline's plans to develop a cabin emergency evacuation trainer, strengthen training on the ATR's rear service door, update passenger briefing material and align cabin crew evacuation commands.
"This is all good news because effective evacuation depends on crew being able to respond consistently under pressure, and for passengers to pay attention to safety briefings, leave bags behind if told to evacuate, and follow crew instructions," she said.
Air New Zealand chief safety and risk officer Nathan McGraw said it was important serious incidents such as this one were thoroughly investigated and learned from.
"We’re grateful to our crew who landed the aircraft safely and evacuated our passengers. TAIC found their actions ensured the safe landing and evacuation of everyone onboard."
In a statement to 1News, McGraw noted the report found no evidence of Air NZ maintenance or operation contributing to the failure of the turbine blade.
He also acknowledged the evacuation "took longer than we would want".
"Real-world evacuations involve uncertainty, time pressure and different passenger responses, and there are valuable lessons from this event. We accept the findings and have already made changes to strengthen our training, procedures, and passenger safety information."
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