Hugh Morrison (85), of Mosgiel, returned from his 17th trip to Texas last week, visiting his friend former Flying Officer Vance "Chippy" Chipman, who has Alzheimer's.
"It is sad to say, but I don't think I will be heading over there again," he said.
After joining the Royal New Zealand Air Force in 1942, Mr Morrison trained as a navigator and was sent to Canada for final training before being posted to Britain.
Assigned as a navigator aboard a Mosquito - then a newly commissioned British combat aircraft - Mr Morrison was paired with a flamboyant young American pilot, Flying Officer Vance Chipman.
"They assigned us a pushbike to get around, and he said, 'I am not having that', and he disappeared for two days and came back with a motorbike."
Based in the south of England, with 605 Squadron, the pair were involved in night incursion work across enemy lines.
"He was a super pilot, one of the best," Mr Morrison said of Mr Chipman.
After flying bombing raids for almost a year, the pair were assigned to different crew, and Mr Morrison was involved in the daring raid on the Gestapo headquarters at Aarhus University, in Denmark.
Mr Chipman, who earned a reputation as a fearless pilot, was shot down over Germany in 1944 and became a prisoner of war.
The pair were reunited 50 years later, when Mr Morrison tracked his former pilot to a Florida residence. Having made plans to visit him in 1995, Mr Morrison, a former school teacher, was dismayed to find, when he finally knocked on his friend's door, he had moved to Texas.
Obtaining his telephone number from a neighbour, Mr Morrison spoke to his friend who told him "to get yourself down here, Kiwi'."
Unable to change his flights, Mr Morrison visited him the next year, and regularly wrote and telephoned his friend.
"However, I have been waiting for a letter from him since I first found him again. He has never written a . . . word."
In all, Mr Morrison has visited his friend 17 times since 1995, his visits coinciding with air force reunions. But this year's visit was poignant for Mr Morrison as he realised it would probably be the last time the pair would see each other.
"He has been getting worse for the last five years. It is quite sad, because we went through so much together, and now he doesn't remember anything. We are not getting any younger, I suppose."
