Incident Details
During the initial climbout of a twin-engine aircraft, the left cockpit door, located behind the pilot's position, opened into the airstream at approximately 50 feet above ground level. The door subsequently separated from the aircraft and struck the left propeller and fuselage skin, causing damage. Following the event, the pilot executed single-engine procedures and proceeded in instrument meteorological conditions to an alternate airport, where an instrument flight rules approach and landing were completed without further incident.
Investigation Findings
Investigators were unable to locate the separated door. It could not be determined whether the door latch malfunctioned or if personnel failed to properly secure the latch before departure. Notably, the cockpit lighting does not illuminate as a function of the door latch, and no warning light exists to alert the crew of an unlatched door. The door hinges are mounted on the aft frame of the door opening, causing the door to swing rearward into the path of the propeller upon opening.
Operational Aspects
The incident occurred during the initial climb phase, which is a critical period of flight. The pilot’s actions in response to the door separation and propeller damage included completing single-engine procedures and safely navigating to an alternate airport under instrument flight rules. The lack of a door latch warning system may have contributed to the inadvertent door opening, but the precise cause remains undetermined.