What happened
During the initial climb phase of the flight, the first officer was operating the aircraft (type not specified). After the aircraft had taken off and the flaps were retracted, the elevator control system failed while the crew was manually retrimming the airplane. The flight crew subsequently returned to the airport and landed the aircraft without further incident; all occupants were not injured.
The investigation
An examination of the elevator control system identified a failure in a cable segment located between fuselage station 74 in the cockpit and fuselage station 310 in the cabin. The failure occurred approximately at the midpoint of a 45-degree change in direction. A metallurgical analysis of the broken cable determined that the cause of the break was fatigue and wear.
Findings
While the aircraft manufacturer mandates that these cables undergo inspection every 4,800 hours, the operator had implemented a reduced inspection interval of 2,400 hours. At the time of the failure, the cables had been last inspected 2,247.5 hours prior. The manufacturer's instructions specify that cable replacement is only required on condition.