Cessna T206 N189JC accident near Porterville, California

Probable cause

The pilot's failure to verify that the rear cargo portion of the right cabin door was adequately secured before flight, which resulted in both portions of the door opening in flight and substantial damage to the fuselage.

NTSB analysis

The pilot reported that, during the preflight inspection and after a passenger had entered the airplane, he ensured that the rear cargo portion of the right cabin door, which also had a forward passenger portion adjacent to the second row of passenger seats, was secure. After completing the preflight inspection, the pilot entered the airplane and saw the passenger close and latch the forward portion of the right door. He then saw the passenger, who was seated in the right, rear passenger seat, struggling with the seatbelt, which passed between the seat and the right cargo door. The pilot suggested that the passenger switch seats, and the passenger moved to the left, rear passenger seat and fastened his seatbelt.

The pilot reported that, during the flight, while maneuvering and descending to 1,600 ft mean sea level, he banked left and then heard a "brief whistle," followed by a "loud boom." He looked behind him and saw that both portions of the right cabin door were open. He returned to the departure airport without further incident.

The airplane sustained substantial damage to the fuselage.

Postaccident examination of the airplane revealed red paint transfer marks on the forward portion of the door from the rear portion door latch, and both door sections could be opened if the latch for the rear door was open. The pilot reported that he believed that the right, rear passenger seatbelt "must have pulled on the [rear] door latch enough to dislodge it." He added that the red paint transfer mark was not there before the flight.

The pilot provided a postaccident examination video, which showed that he was able to use the larger airbag section of the seatbelt to wedge open the rear cargo door latch.

The pilot reported that there were no preaccident mechanical failures or malfunctions with the airplane that would have precluded normal operation.

Text from the NTSB. Open the NTSB docket for GAA19CA372 for the full record.