Even if after the 9/11 terrorist attacks the cockpit doors were fortified, pilots and co-pilots have ways to get into the cockpit in an emergency. But this is working only if another security system is not activated inside. In that event, no one can get in, Gregory Feith, a former senior air safety investigator with the Nat¬ional Transportation Safety Board, explained. So at this time no one knows what happened onboard of Flight 9525. However, in such circumstances, the hypothesis of an intentional crash must be considered. “Procedurally, something was very wrong,” said Glen Winn, an aviation instructor at the University of Southern California and an expert in aviation security and anti-terrorism. There is another strage thing, the Germanwings flight had issued no distress signal or other communication during its last minutes. “It’s never one thing, Every aircraft mishap is composed of more than one causal factor,” believes Thomas Anthony, director of USC’s Aviation Safety and Security program.