Dr Ireland had previously lived in Manawatu but had been in Southport, on Australia's Gold Coast, for a number of years.
He was understood to be back in New Zealand for the funeral of a friend.
An employee who worked for Dr Ireland at the Gold Coast Chiropractic Centre for 10 years told APNZ he was "a wonderful man".
Dr Ireland said on his practice's website that he had worked as a chiropractor in New Zealand for 18 years before he and his wife decided they wanted to live "on the beautiful Gold Coast".
"We sold our practices and moved here in 2002. We bought Gold Coast Chiropractic Centre and with our three children have settled here permanently," he wrote.
"Living here in Southport allows me the ability to enjoy an outdoor lifestyle almost 12 months of the year. I run, play tennis with the kids, play golf and enjoy fishing and boating."
Dr Ireland worked as an engineer before studying in the United States to become a chiropractor. A strong believer in the power of his work, he said 30 years of chiropractic treatment had cured his own hayfever.
Dr Saxe was a well-known Manawatu doctor who had worked extensively in South Africa and New Zealand.
He was managing director at the Palms Medical Centre in Palmerston North, where his wife, Joanne, is a practice manager.
He had been a member of the MidCentral District Health Board for two years.
Dr Saxe had also worked as a GP and a pharmaceutical company manager in South Africa in the 1990s.
In his spare time he was a keen flyer, and had his private pilot's licence. He belonged to the Feilding Aero Club, the Manawatu Aero Club and the Rifle, Rod and Gun Club in Palmerston North.
Dr Saxe and Dr Ireland were in an Aerostar Yak 52TW, co-owned by Dr Saxe, when they crashed in the Feilding park about 10.45am on Monday.
CAA lead safety investigator Al Moselen said he and colleague Steve Walker had been examining the site.
"It has been suggested that the Yak 52 was carrying out aerobatics prior to the accident but this has not been confirmed."
The wreckage is expected to be removed today.