Incident Overview
A passenger reported that shortly after rotation for takeoff, the cabin door on the right side of the aircraft came open, creating a loud noise. The passenger stated that both he and the pilot were unable to close the door, prompting the pilot to elect to land.
Maneuvering and Accident
According to the report, the pilot executed a steep right turn followed by a steep left turn to maneuver back to the runway. However, the aircraft entered a steep descent and crashed in a nose-down, left-wing-low attitude.
Investigation Findings
No preimpact part failure or malfunction of the aircraft was found during the investigation. The passenger reported that before the flight, he had shut the door, but the pilot did not check to see if it was locked. According to the aircraft flight manual, the pilot was responsible for ensuring the door was closed and locked. The manual also stated that should the door come open in flight, the pilot should land in a normal manner.