Robert 'Roy’ Watterson (67), originally from Belfast, was flying the light aircraft that went down over the sea near Brisbane.
Air accident investigators are probing how the crash happened last Sunday.
Mr Watterson, who founded industrial supply company Lincom in 1994 after emigrating to Australia, died in the crash last week along with 41-year-old Chris Mocanu, and Mr Mocanu’s two children, Lucas (9) and Lavinia (10).
The Northern Irishman, a father-of-three, was well known in business circles as the main distributor in Australia, New Zealand and the Pacific Islands for Powerscreen. Mr Mocanu was a hire manager for the company.
Catherine Di Blasio, the mother of the two children, told the
Brisbane Courier Mail that the flight was a birthday surprise for her son. She did not know the children were going on the flight.
Management at Powerscreen paid tribute to Mr Watterson, describing him as a man of "high and exacting standards" and the "epitome" of the brand in his adopted homeland.
"Having been a dealer for many years, Roy was a great character who was widely admired and respected among the Powerscreen family worldwide," the company said in a statement posted on social media.
"Roy had very high and exacting standards and was the epitome of the Powerscreen brand across his adopted homeland region.
"He was a very proud man. He was proud of his Northern Irish roots and loved bringing Australian and New Zealand customers back to the factory every two years around Hillhead exhibition – just recently he was making plans for the 2022 visit.
"He was proud of his business, still family-owned and going strong under the watchful eye of sons Stephen and Mark, daughter Lindsey and his loving partner Jan.
"More than anything Roy was all about family. The start of any call was trading stories about family and what all the kids were up to.
"With the arrival of any new Powerscreen baby, the Roy Watterson trademark Koala bear teddy was not far behind, a very thoughtful gift from the other side of the world."
In a statement, the Lincom group said the loss of the two children, Mr Watterson and Mr Mocanu was deeply felt across the entire team.
"Roy established Lincom over 25 years ago and saw it grow and develop over the years," the company said.
“His career was fuelled with passion and integrity. His charming personality and unique friendliness turned customers into good friends. His big heart was an inspiration for us all."
The Australian Transport and Safety Bureau (ATSB) has launched a investigation into the crash. An initial report said the plane was "reported to be returning to the aerodrome" when it crashed into the sea.
A preliminary report is expected to be completed in about eight weeks.
"Should a critical safety issue be identified during the course of the investigation, the ATSB will immediately notify relevant parties, so that appropriate safety action can be taken," the ATSB said.
In her interview with the
Courier Mail, Ms Di Blasio said: “He (Lucas) had a recent birthday in November and his dad told them that it’s a surprise, a present, but all he said was it was an experience that you will love. Up to that morning the kids didn’t even know.”
Ms Di Blasio, who was separated from Mr Mocanu, said she expected them back for lunch, but when she rang his mobile it came back “out of service”.
“Then I thought they were ringing my doorbell, but when I opened the door there was three child protection service detectives and they told me the bad news,” she said.
“Even the guy had trouble telling me, he didn’t know which words to use, it was pretty horrible.
“When they came to my house, the detectives, I was wrapping the kids’ Christmas presents.”