A Southwest pilot was forced to enter through the cockpit right side window after a passenger accidentally locked the flight deck door entrance through the cabin.
The passenger inadvertently pushed the cockpit door which became locked as he tried to use the lavatory during boarding. Unable to open the cockpit door from the cabin the Pilot was forced to enter the cockpit through the right-hand side window from outside.
Southwest Airlines issued the following statement regarding the matter:
"During the boarding process, while other Customers and Flight Attendants were onboard, a Customer opened the forward lavatory door and inadvertently pushed the Flight Deck door closed (which locked) while the Pilots scheduled to operate the flight were preparing to board the aircraft. The Customer did not close the aircraft main cabin door. One of our Pilots unlocked the door from a Flight Deck window, and the flight departed as scheduled."
Cockpit doors are designed to provide a secure barrier between the cockpit and the cabin of an aircraft. They are typically made of reinforced materials and are equipped with locks and other security features to prevent unauthorized access to the cockpit.