Piper PA34 N999CR accident near Anderson, Indiana

Probable cause

The loss of left engine power due to an incorrectly adjusted fuel servo and the airplane's nose up trim which resulted in the airplane steep climb, loss of airspeed, and aerodynamic stall and subsequent impact with terrain.

NTSB analysis

The pilot planned to ferry the twin-engine airplane to another airport for the annual maintenance inspection. Several witnesses saw the airplane's departure. Two of the witness reported that the airplane engines didn't sound "normal". Several witnesses reported that the airplane appeared to pitch up, before stalling.

A video from the airport's security camera revealed that the airplane appeared to climb steeply; the airplane's wings rocked back-and-forth, and the airplane disappeared out of view. When the airplane reappeared in the camera's view, the airplane was in a descent with the left wing low. The airplane collided with terrain and the airplane cabin area was largely destroyed by the impact.

Examination of the airplane found the stabilator trim actuator screw was near its maximum nose up setting. The left engine was removed from the airframe and tested in the engine manufacturers test cell. The engine test run reveled the engine did not produce full rated horsepower and on occasions produced black exhaust which was indicative of a rich fuel air mixture. The fuel servo was replaced with a new unit and the engine was able to produce rated horsepower. Further examination of the original fuel servo showed that the control linkage (rod and link assembly), was installed incorrectly.

The accident is consistent with loss of power on the left engine due to an incorrectly installed fuel servo and an excessive nose up trim setting, which resulted in steep climb angle, a loss of airspeed, and an aerodynamic stall.

Text from the NTSB. Open the NTSB docket for CEN19FA135 for the full record.