This video shows how a pilot might have been locked out of the cockpit of Germanwings 9525

Inside the cockpit of an A320 aircraft.
Inside the cockpit of an A320 aircraft.
Image: Reuters/Kham
We may earn a commission from links on this page.

The latest information about the Germanwings flight 9525 that crashed on March 24 in the French Alps, killing 150, is chilling: one pilot was locked out of the cockpit, and tried unsuccessfully to get back in before the crash, The New York Times reported, while the co-pilot appeared to have brought down the plane deliberately, according to the prosecutor in France who is leading the criminal investigation.

The situation raises questions about how pilots and other crew can access the cockpit of a plane, in this case an Airbus 320, once they leave it.

After the attacks on the US on Sept. 11, 2001, in which hijackers stormed cockpits and overtook pilots before flying planes into the World Trade Center and the Pentagon, and crashing another in a field in Pennsylvania, airplane manufacturers and airports introduced a host of stepped-up security measures, in response to new regulations designed to make cockpits more secure.

Airplane manufacturer Airbus rolled out a new system designed to prevent unauthorized entry. “A toggle control in the cockpit enables the crew to control access to the cockpit and secure the door in case of need,” Airbus said when it was released. Here is a 2002 video, copyrighted by the aircraft manufacturer, explaining Airbus’s new “Reinforced Cockpit Door:”

The cockpit door automatically locks, and in most situations, anyone outside the cockpit needs to have permission from the pilots inside to enter, the video explains. Pilots in the cockpit need to move a switch to the “unlock” position to open the door.

In the case of “crew incapacitation,” there is an emergency access procedure: someone outside the cockpit must punch an emergency code into the door access panel, then can enter 30 seconds later if there is “no action from the crew.” The video seems to imply that someone inside the cockpit could override that emergency action, but that is not entirely clear.

In response to specific questions about how the emergency access procedure works, and might be overridden, an Airbus spokeswoman told Quartz: “We are aware of the media reports, and we have no information from the authorities that confirms this report and we are seeking more information. We will not take part in speculation on the causes of the crash.”

No one knows yet what exactly happened on flight 9525, but the most recent information will raise new concerns that airplane cockpits are too difficult to enter. The Germanwings pilot was recorded by the cockpit voice recorder trying to break the door down from outside, the official involved in the investigation said.