Cessna 310R N5080J accident near Duluth, Minnesota

Probable cause

The failure of the left engine induction coupling during takeoff, which resulted in a total loss of left engine power and an uncommanded left yaw/roll due to asymmetrical thrust and increased drag, from which the pilot had insufficient altitude to recover control of the airplane.

NTSB analysis

The pilot reported that he was conducting a post-maintenance flight after some adjustments were made to the multi-engine airplane’s avionics equipment. The pilot flew an instrument landing system (ILS) approach and made a full-stop landing on the runway. After a brief wait, as instructed by the air traffic controller, the pilot began his next takeoff. Shortly after rotation, the airplane rolled to the left, and the pilot was unable to regain airplane control using aileron and rudder inputs. The airplane settled into the ground in a near-level attitude. During the impact sequence, the nose landing gear and right main landing gear collapsed, which resulted in substantial damage to the right wing and fuselage.

Examination of the airplane revealed that the left engine’s rubber accordion coupling in the induction system between the throttle body and the engine was split. There was no impact damage in the area of the engine and this split was not due to the damage during the accident sequence. No other anomaly was discovered that would have prevented normal operation. The airplane’s most recent annual inspection was conducted about 7 months before the accident, and the airplane had accumulated about 60 hours since the inspection. Review of maintenance information did not reveal a recommended replacement interval for the coupling.

Based on the evidence, the split in the induction coupling allowed a large induction leak that likely resulted in a total loss of engine power on the left engine due to the lean fuel/air mixture that resulted. The loss of power on the left engine resulted in the uncommanded left yaw/roll due to asymmetrical thrust and increased drag, from which the pilot had insufficient altitude to recover control of the airplane.

Text from the NTSB. Open the NTSB docket for CEN24LA242 for the full record.