Inside the co-pilot's Düsseldorf home, investigators found a torn up sick note excusing Andreas Lubitz from work the day he deliberately rammed a jet full of people into the French Alps.
No suicide note was found but other medical documents revealed Lubitz had an existing illness and had reportedly received treatment for depression.
A spokesperson for the Düsseldorf prosecutors’ office said the evidence supports the preliminary assessment that the co-pilot withheld the information from his employer and colleagues.
Former Air Canada pilot Raymond Hall of Winnipeg has logged 20,000 hours on a commercial carrier.
He was shocked to hear of the details of the crash which have raised questions about mental health testing for pilots here in Canada.
"I can't imagine anybody not being horrified at the nature of this event,” said Hall.
"It is really unfortunate that an individual who apparently had some difficulties should choose to end not only his life but others in this manner."
Transport Canada said it reviews every pilot's medical history to check for signs of psychosis and suicidal behavior.
But former Transportation Safety Board investigator Bryce Fisher said the focus of a pilot's medical review is mainly physical.
"The psychological or mental health portion of it, I would argue, is largely voluntary,” Fisher told CTV’s Canada AM.
Hall said it largely falls upon airline crew members to monitor the well-being of their colleagues—whether it's an issue with fatigue, drugs and alcohol or mental health.
"To be able to intervene and say to an individual, 'Are you sure everything is okay? Is there a problem here?' And that challenge-response system is generally pretty effective," he said.
In the case of Germanwings flight 9525, it appears the pilot didn't get any indication something was wrong with his co-pilot.
Hall believes the crash could lead to more changes.
"The entire history of aviation safety is built on the accident record from before of course,” he said.
The airline Lubitz worked for, Lufthansa, said there was a gap in his training six years ago but would not elaborate on why.
Reports from German media say he spent 18 months receiving psychiatric treatment and now it appears investigators are examining whether he'd recently been dealing with a personal life crisis.
A Winnipeg psychologist said it’s common for employees to withhold information about mental illness from their employer and colleagues.
Dr. Teresa Sztaba, the executive director of the Manitoba Psychological Society, said people who are suffering also may not be thinking clearly and may not make good decisions.
"There's fear of loss of job. There's fear of what your coworkers will say, what your boss will say. Will you still be respected? Will you still be considered competent? Will you be given the supports that you need?"
