During a 22-year RAF career, he travelled around the UK extensively, with a short deployment to the Falkland Islands, before deciding to settle in New Zealand in 2005.
David stayed put in Sheffield, in Yorkshire, but moved house, and with it, Stuart lost his last point of contact.
The pair tried to find each other, but for quarter for a century they remained apart, not knowing what had become of each other.
But earlier this year, they finally tracked each other down through Facebook.
It led to father-of-two Stuart and his partner Lara Franklin, 41, flying from their home in Wellington back to his English homeland.
"David said he wouldn't have recognised me in the street. It was incredibly emotional," Stuart said.
During the reunion, retired chef David handed his younger brother 24 birthday cards.
"All these years I never forgot his birthday," he told the Daily Mail.
"I bought him a card every year and used to write him emotional messages.
"It helped when I was ill and had two strokes - it gave me someone to turn to."
Last year, David found Stuart's 21-year old daughter Tiffany on Facebook.
They made contact but a "long emotional email" from Stuart never reached him.
David wrote in his birthday card that year, 'I guess this is goodbye - I tried to get in touch but I haven't heard anything, so I suppose you're not interested'.
However, he again reached Tiffany, which resulted in a Skype call from Stuart.
"It was very emotional. We cried quite a lot. It was very difficult to actually speak to each other," said Stuart, an aviation expert for an industry training organisation.
Within a week, Stuart, now a New Zealand citizen, decided he needed to fly the 18,000kms around the world to the UK as quick as possible.
He arrived in Sheffield on October 3 and had a week with his brother.
"I had pretty much given up hope in ever tracking him down - and he had done the same thing - so it was a very special experience," Stuart said.
"We will never lose touch again."
