Private Joe Cox crouches in dense Vietnamese jungle, waiting for the reassuring "whump-whump" sound.
Rotor blades roar above the canopy. The highly-skilled helicopter pilot drops the dark green machine onto the tiny landing zone and plucks the New Zealand soldiers out of the danger zone.
"Hueys were the best noise you could ever hear, and those pilots were gods to us," said Mr Cox, a 67-year old war veteran.
Today, he rode one of the Royal New Zealand Air Force's Bell UH-1 Iroquois helicopters, known as Hueys, for a final time.
After nearly 50 years of service, the famous, versatile aircrafts - which have served in war zones around the world, and carried out search and rescues across New Zealand the Pacific - will be phased out.
In July they will be replaced by new bigger, faster A109 and NH90 helicopters as part of a $2 billion fleet upgrade.
The distinctive chop of the Huey's rotors brought back many memories for Vietnam veterans taken on a 20-minute flight over Christchurch today.
For Kiwi soldiers fighting the Viet Cong, the arrival of Hueys meant shot and wounded men could be airlifted to hospital within 30 minutes.
Or else it meant fresh ammunition or food.
"We all had total faith in those machines and their pilots," said Whiskey 3 company veteran Blue Caldwell.
"They took us in, pulled us out, often in bloody hairy spots, and all the pilots had for protection was a piece of metal under their arse."
His platoon sergeant during the 1969/70 tour of duty was Denny King.
For him, the sound of a Huey coming in meant that his wounded soldiers had a chance of survival.
"Within 30 minutes they could get a wounded mate to hospital. They meant everything to us on the ground," the 74-year old said.
After July, two Iroquois will be preserved and publicly displayed at the Air Force Museum of New Zealand, at Wigram, in Christchurch, while another will go to the National Army Museum, Waiouru.
The rest will be put out to tender.
Mr Caldwell, 65, is sad to see them go.
"But that's life - it happens to us all."