They directly contributed to the deaths of two patients, probably had an effect on one case and possibly affected five others, according to a long-awaited report by a panel of experts.
It reviewed 40 cases, which were among several hundred from January 2006 to June 2012 that were screened, said Dr. Dan Cass, the province's interim chief coroner.
The operational issues included policies and procedures that led to a delay in launching an Ornge aircraft on call, a design flaw in an aircraft cabin and the equipment used by paramedics, which affected the care of a patient, he said.
Even one death is too many, Cass said. But Ornge does provide "excellent" care to patients across the province, he said.
The report "was about fact-finding, not fault-finding," he said.
"The purpose was not about pointing fingers or assigning blame," Cass added. "The purpose of this review was to learn from tragic deaths and to use that knowledge to prevent future deaths."
Ornge transport directly contributed to the death of a 17-year-old boy in northern Ontario, who shot himself in the face and was being transported to another hospital outside the province, the report found.
Transport delays, including a mechanical delay in departure and transferring the teenager to a land ambulance, coupled with the lack of effected sedation of the patient had a "definite impact" on his death, the report said.
The second case involved a 22-year-old man in northern Ontario with a history of alcohol and drug misuse who became ill after a two-day drinking binge. The oxygen ran out during transport and despite attempts to resuscitate him, the man was pronounced dead at hospital.
The report found that the oxygen ran out because the rate of flow was set higher than it was supposed to. It also noted that a nurse — who replaced a paramedic who fell ill — was unfamiliar with the equipment and aircraft, which may have contributed to the mistake.
A legislative committee looking into Ornge had heard that several incidents in which patients died were related to the design of the interiors of Ornge's AW-139 helicopters.
They included jammed stretchers, critical patients unable to sit upright and paramedics unable to perform CPR.
Ornge paid $144 million for 12 helicopters from Italian firm AgustaWestland. Ornge also paid $6 million for the Swiss-manufactured Aerolite medical interiors.
There were some cases in which the medical interiors of the aircraft were "problematic," Cass said. But the inability to perform CPR wasn't a factor in any of the patient deaths.
Both Ornge and Health Minister Deb Matthews said they'll act on all of the 25 recommendations in the report. Fifteen have already been implemented, Matthews said.
Ornge's new management has taken a "much more proactive approach" to addressing concerns raised by staff, she said.
When questions were raised about the medical interiors, Matthews said her ministry was told by Ornge's previous executives that it had been addressed.
"Front-line staff were saying that this was a problem, and the management said, no this isn't," she said.
"Well, in fact it was a problem. So the new management has fixed that problem."
Ornge has already installed temporary medical interiors in the helicopters so that CPR can be performed and stretchers don't jam, said CEO Andrew McCallum, who ordered the expert review last year as chief coroner.
"A number of the issues raised by the coroner had been brought to our attention by frontline staff, and we took steps to act upon these prior to the release of the coroner's report," he said in a statement.
Whistleblowers, including families of dead patients, were ignored for years by the ministry, said NDP health critic France Gelinas.
The report has proven them right, she said. It's also revealed the consequences of the government's failure to oversee Ornge for so many years.
"The part that the minister always refuses to do, is to admit that they had a huge role to play in this," Gelinas said in an interview.
The changes at Ornge could have been done years ago, if the government had done its job, she said.
Ornge, which is under a criminal probe for financial irregularities, has been under intense scrutiny for more than a year.
Ontario's auditor general has questioned Ornge's business dealings and slammed the government for failing to oversee a publicly funded organization that received $730 million over five years and borrowed $300 million more.
The review was launched last August after the release of cabinet documents that showed the government investigated 26 deaths involving its troubled air ambulance service since 2007.