The National Transportation Safety Board (NTSB) has released its final report regarding the July 9, 2011, plane crash in Demopolis that claimed seven lives.

The NTSB determined the cause of the accident to be the pilot’s failure to maintain airplane control during a single-engine approach and his failure to fly an appropriate traffic pattern for a single-engine landing, the reports outlines.

Contributing to the accident was a total loss of engine power on the right engine due to fatigue failure of the cam gear.

The aircraft, a Cessna 421C, was in cruise flight at 21,000 feet when the pilot, Fred Teutenberg, declared an emergency due to a rough-running engine. At this time, the aircraft was about 10 miles from Demopolis Municipal Airport. About four minutes later, the pilot reported he had to shut down his right engine.

According to the airplane information manual, procedures for landing with an inoperative engine call for excessive altitude, however, the airplane’s last radar return showed the plane at an altitude of 600 feet and about three miles from the approach of the runway.

The NTSB believes the plane was either on or turning to the final approach course when it rolled and impacted trees. The airplane came to rest about eight-tenths of a mile north of the runway threshold, upside down. A majority of the plane, including the cockpit, main cabin and left wing were consumed by a post-crash fire.

The investigation revealed that the right engine failed when the camshaft stopped rotating after the camshaft gear experienced a fatigue fracture on one of its gear teeth.

The pilot, 42; wife, Terresa, who was in her mid-30s; daughter Emma, 2; son Peyton, 4; daughter Ellie, 6; son Brendon, 9; and son Will, 10 were all killed in a plane crash at approximately 6:34 p.m. Saturday evening.