New Zealand ‘s air force has evacuated three staff from an Antarctic research base in a highly difficult operation battling total darkness and severe weather. The United Nations Science Foundation employees were retrieved from McMurdo Station, a US research base, overnight on Tuesday in freezing -24C temperatures.

One person required urgent medical care and the other two needed medical attention, the Royal New Zealand Air Force (RNZAF) said in a statement. The C-130J Hercules aircraft landed safely in Christchurch, on New Zealand’s South Island, on Wednesday morning following a challenging overnight journey.

RNZAF did not provide specific details of the emergency but said the rescued employees were safe and receiving medical treatment in New Zealand. Andy Scott, a RNZAF Air Commodore, said extreme weather and darkness made winter flights to Antarctica among the hardest flights air force pilots can perform. ‘The crew can only attempt the flight after detailed analysis of the weather and airfield state,’ he said.

‘The United States Antarctic Program Winter Team must physically create the runway before we can depart by ensuring the ice is groomed and suitable for landing. ‘Although they determine it is safe, it’s still an extremely challenging environment to fly in on night vision goggles due to the extreme weather conditions, which are highly changeable at this time of year and makes accurate forecasting a challenge’. Beyond a certain latitude, there are no airfields to divert to in case of an emergency making the flight path particularly dangerous.

The aircraft was flown to Christchurch from Auckland on Sunday afternoon, where the crew waited for optimal flying conditions. On Tuesday afternoon, the crew found an opening and decided to work throughout the night to complete the mission. Defense Force medical personnel including a medical officer were on board to deliver care to the patients mid-flight.

Upon landing, the aircrafts engines were kept running to keep them warm during refueling – a technique known as ‘hot refueling’. The total operation took about 19.5 hours. The US embassy expressed its ‘deep appreciation’ for the bravery of New Zealand’s air force in a statement following the mission.

‘This mission wasn’t just difficult; it was one of the most technically demanding operations an aircrew can face,’ said Melissa Sweeney, the US chargé d’affaires in New Zealand. ‘This required absolute precision… This is the kind of mission that tests every ounce of skill and bravery.’

RNZAF rescued an American patient from the same station in June last year, taking advantage of a brief window of calm overnight weather. It followed a similar rescue mission in 2021, the first time night vision goggles were used during an RNZAF Antarctic recovery operation.