Determined to make sure their much-loved headmaster would never forget his final days on the job, his staff and students hatched an ingenious plan.

On Wednesday morning, an unsuspecting Mr Dewar was kidnapped by his executive teachers and bundled into a helicopter for a flight over the Illawarra coastline.

As the aircraft swooped over Albion Park to return to the airport, he spotted hundreds of waving bodies standing in his school's back oval: his pupils spelling out a giant "Goodbye Mr Dewar!".

Then as he walked back through the school gates they formed an archway and rushed to give him high-fives, an experience he described as "completely humbling".

"When I spoke to the school my emotions kicked in, it was a very emotional occasion," he said.

"I was especially impressed because the entire school kept [the surprise flight] quiet - so five and six-year-olds right through to 12-year-olds - for a whole school term."

Mr Dewar started his working life as a metallurgist at Port Kembla steelworks.

He gained a scholarship to study at Wollongong Teachers College and started his first teaching job in 1974.

With a passion for making a difference in children's lives, he taught all over the region and, since 1988, has led Mount Keira, Mount Kembla, Gwynneville, Warilla and Mount Warrigal public schools.

From Mt Warrigal Public School, five years ago in 2007, Mr Dewar took the helm at Mount Terry, where he clearly made quite an impression.

Ever modest, the headmaster was adamant he had done nothing special to earn such respect, putting his success as a principal down to a talented team of teachers.

"I keep telling all of them I'm nothing special, I'm just me," Mr Dewar said.

"But I try to care for the people I work with and the children in the school.

"I also have high expectations and I've tried to give all of them the support they all need as life's bumps are hit.

"But that's just me and I think that's a lot of other people - so I haven't tried to do anything significantly different."