Did the locked-out pilot take an axe to the cockpit door in a desperate effort to save the doomed plane?
The grim new report says the axe was used after deranged co-pilot Andreas Lubitz locked the door and refused to let the captain back in.
Peter Sirucek of Southern California Aviation spoke to INSIDE EDITION's Jim Moret.
He said, "The door is fortified that you can never enter it at any short period of time."
Moret asked, "What it is made of?"
Sirucek said, "Kevlar."
Moret responded, "Kevlar, like a bulletproof vest?"
"Yes," said Sirucek.
Sirucek says axes on American planes are secure and not accessible to potential terrorists.
The captain reportedly first tried pounding on the door with his fists. Then, he tried to kick the door in. When all that failed, he reportedly went for the axe and vainly tried to smash his way in.
In the wake of Lubitz's suicidal meltdown, airlines around the world are adopting the U.S. rule that there must be two crew members in the cockpit at all times. Among the airlines are Lufthansa, Virgin, Air Canada, Icelandair, and Norwegian Air.
There are other strict rules in the U.S. about access to the cockpit. Passengers are not allowed to congregate near the cockpit door. When the pilot opens the door, for example to visit the bathroom, flight attendants will block the aisle with a food cart.
INSIDE EDITION is also learning new details about Lubitz's history of psychological issues, including a claim that a doctor declared him unfit to fly the day of the crash.
A ripped-up medical note was found in his home.
CBS News correspondent Kris Van Cleave is at the crash site in France.
He told INSIDE EDITION, "That ripped up sick note is raising a lot of eyebrows with people because here clearly was a doctor saying, 'You don't need to fly that day. There is some illness here.' Instead of heading that medical advice, that note was ripped up, left in his apartment, he got on the plane, and we know what tragically happened when he did."
It's also being reported that when he attended a flying school in Phoenix, Arizona, Lubitz had to repeat classes several times due to depression.
And he had problems fitting in with other pilots who nicknamed him "Tomato Andy" because he started out as a flight attendant serving meals.
He also reportedly recently broke up with his girlfriend.
Van Cleave said, "There have been reports of depression and talk now if he had been fit to fly."