The plane crashed on Tuesday afternoon and a search party found the wreckage around 4km west of the Renmark Aerodrome, north east of Adelaide, at 7.10pm.
Charter flight company Rossair owned the Cessna Conquest aircraft and has confirmed the identities of those killed.
They are Rossair trainee pilot Paul Daw, 65, Rossair chief pilot Martin Scott, 48, and Civil Aviation Safety Authority inspector Stephen Guerin, 56.
Adelaide-based Rossair grounded its fleet as a precautionary measure and said the deaths have left its staff in “deep shock”.
“Our deepest sympathies are with the family members concerned. This is an extremely sad event,” its executives said in a statement on Wednesday.
CASA has paid tribute to Guerin who it said was observing the flight as part of the authority’s routine safety work.
“Mr Guerin is remembered by CASA colleagues as passionate about aviation, meticulous about safety and widely respected,” the authority said in a statement.
“He was active in community service and known as a ‘true gentleman’.”
First pictures of the Renmark plane crash that killed three men. Report in 7 News at 6pm. pic.twitter.com/TfNUAYsxA1
— 7 News Adelaide (@7NewsAdelaide) May 30, 2017
Transport Minister Darren Chester said he was “saddened” by the incident.
“On the behalf of the Australian government I would also like to extent thoughts and prayers to the family and loved ones of all those on board,” he said in a statement.
Police remain at the crash scene while several Australian Transport Safety Bureau investigators are travelling there from Adelaide, Canberra and Sydney.
The investigators are expected to spend at least three days at the site trying to piece together what happened.
Rossair said the plane had been flying from Adelaide to the Riverland and was returning when it crashed at about 4.30pm.
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