History of the Flight
The aircraft, a DA40D Diamond Star registered G-JKMG, was being used for a sales demonstration flight on 8 August 2007. Prior to departure, the front canopy and rear clamshell passenger door had been opened and closed multiple times. During taxi, the front canopy was latched open for ventilation, causing a red DOOR OPEN warning on the Garmin G1000 avionics. Before takeoff, the canopy was closed, but neither pilot noticed that the warning remained illuminated. After becoming airborne, both pilots realised the door warning was still active, and the commander recognised that the rear passenger door was likely unlatched. At approximately 700 ft, the commander reached for the door in an attempt to close it. The door then fully opened, its hinges failed, and the door detached from the airframe. It passed over the fuselage and struck the right horizontal stabiliser, causing significant damage. The aircraft continued its circuit and landed without further incident. The door was later recovered from a field.
Damage
The rear door detached from the aircraft, and the horizontal stabiliser sustained damage.
Pilot Assessment
The commander, a 56-year-old private pilot with 2,318 total hours (302 on type), acknowledged that he did not secure the rear passenger door and failed to identify the door warning message prior to departure.