What happened
On 15 October 2019, a privately owned Diamond DA42, registration N181CW, was preparing for a non-scheduled flight from Seletar Airport, Singapore, to Kuching, Malaysia. During the take-off roll, as the aircraft reached approximately 40 knots, the passenger door unexpectedly detached from the fuselage. The pilot, alerted by a radio shout from a following aircraft, immediately aborted the takeoff and vacated the runway.
Upon exiting the runway, the pilot discovered that the passenger door was missing. The door, along with the forward hinge and portions of the aft hinge, had been torn from the aircraft frame. There were no injuries to the single occupant on board.
The investigation
Investigators examined the aircraft's door mechanism and the cockpit warning systems. While the pilot and a nearby mechanic both believed the door had been properly closed and latched, physical evidence suggested otherwise. The investigation found that the door frame and locking bolts showed no signs of the heavy damage that would have occurred had the door been properly latched and then forced open. Instead, observations from another pilot indicated the door had rotated upwards, suggesting it had unlatched and opened during the high-speed roll.
Technical analysis focused on the aural warning chime system. The investigation established that the audio warning only energizes if all doors are closed and latched and the Avionics Master Switch (AMS) is active. Because the door was likely not fully latched, the chime system failed to activate, even though a visual "Door Open" warning appeared on the Primary Flight Display (PFD).
Findings
- The passenger door was likely closed but not properly latched before departure.
- Because the door was not latched, the aural warning chime system was never energized, leaving the pilot without an audible alert.
- The pilot may have missed the visual "Door Open" warning on the PFD during the pre-take-off checklist.
- The movement of the aircraft during the take-off roll caused the unlatched door to open and eventually detach from the hinges.