A charity that finds flights for sick people from regional areas has been warned to consider the safety and risk to passengers after two fatal accidents in seven years.
The Australian Transport Safety Bureau has found community service flights organised by Angel Flight have a fatal accident rate seven times higher than other private flights.
They are also four times more likely to be involved in other safety incidents.
At the same risk level as other private operators, Angel Flight could have expected one fatal accident in 37 years but six people have died in 20,000 flights undertaken since the organisation set up in Australia in 2003.
"The community could reasonably expect that community service flights would have a level of safety at least commensurate with other private operations, if not higher," ATSB chief commissioner Greg Hood said on Tuesday.
"However the ATSB's analysis has demonstrated those flights conducted for Angel Flight are actually less safe than other private operations and more likely than other private operations to experience fatalities."
The ATSB investigation came after a pilot and two passengers were killed when an Angel Flight service crashed at Mt Gambier in South Australia in June 2017.
Businessman Grant Gilbert, 78, was flying the SOCATA TB-10 Tobago to take 16-year-old Emily Redding to Adelaide for medical treatment, accompanied by her mother Tracy.
The investigation found Mr Gilbert, who had less than three years' experience, took off in heavy fog despite not being qualified to fly in cloud using the plane's instruments.
Shortly after, he likely lost visual cues and became spatially disorientated. The plane crashed within 70 seconds.
The same day, two Rex airline flights into Mt Gambier were delayed by poor weather.
Another plane running an Angel Flight mission crashed in similar circumstances near Nhill in Victoria in 2011, also killing all three people on board.
Angel Flight has more than 3000 volunteer pilots on its books and organises about 1600 flights a year.
It doesn't operate as an airline and therefore doesn't face the same regulation as charter flights or commercial airlines.
"The ATSB found the Angel Flight organisation did not pressure pilots to fly in conditions beyond their capability but some circumstances can lead to a pilot feeling pressure in any case, such as having the responsibility to fly unrelated ill passengers to meet medical appointment deadlines," Mr Hood said.
Angel Flight called its operations "missions", which Mr Hood said had emotional connotations.
It has told the investigator it will drop the term, although its website on Tuesday still said doctors caring for people they believed qualified for the charity's help "can apply for a mission".
It will also do an inventory of the qualifications of its volunteer pilots and establish a mentoring program and a safety management system.
The ATSB recommended Angel Flight consider paying for commercial flights where possible, saying many were comparable or cheaper than the charity's fuel reimbursements.
But Angel Flight said this did not properly factor in the infrequency or non-existence of flights into country regions or the inconvenience and difficulties faced by the elderly and young families at major city airports.
"It appears to work on the assumption that city specialists and hospitals will gear their appointment times around airline timetables," the organisation said.
"Angel Flight does use airline flights where practicable and necessary and will continue to utilise these services."
It said it was regrettable the ATSB made no relevant safety recommendations or offered guidance to pilots flying in poor weather.
Australian Associated Press