Cessna 310D N6798T accident near Ennis, Texas

Probable cause

The partial loss of right engine power due to reduced fuel flow as a result of the contamination of the fuel screen.

NTSB analysis

The pilot was conducting a personal flight in a multiengine airplane with two passengers when the accident occurred. According to one of the passengers, the pilot chose to perform a go-around while on final approach; however, the reason for the go-around was not understood. The airplane side-stepped to the right of the runway and immediately rolled to the right. The airplane impacted a field of cedar trees, where a post-impact fire ensued and destroyed the airplane.

Debris in the initial impact crater show that the right wing and right engine impacted the ground first. Both the left and right propellers exhibited chordwise/rotational scoring, which was consistent with both propellers rotating at impact; all damage was consistent with high impact forces. The left propeller exhibited damage consistent with rotation at a higher power level when compared to the right; however, the level of engine power could not be determined definitively from either propeller. Both propellers exhibited damage consistent with rotation at a low blade angle and neither was in a feathered position. There were no discrepancies noted that would preclude or degrade normal operation on either propeller. The left engine was examined and there were no preimpact mechanical failures or malfunctions that would have precluded normal operation.

The right engine was run and initially ran rough. The fuel plug and screen assembly from the fuel injection control assembly was removed and black debris, small string-like fibers, and metallic particles were observed obstructing the screen. Analysis of the debris revealed polyurethane, and metallic particles of brass (zinc and copper) and aluminum. The brass and aluminum were most likely components of the fuel system.

The flexible fluid-carrying hoses had not been replaced since 2001 and were prone to degradation if not replaced after 12 years. The polyurethane and string-like fibers were consistent with a flexible fluid-carrying hose. It is likely that the fuel hose from the fuel system degraded over time and plugged the fuel screen for the right engine which resulted in a partial loss of engine power.

A review of the maintenance records did not indicate that the fuel plug and screen from the fuel injection control assembly were cleaned during the August 2022 annual engine inspection as recommended by both the Cessna Model 310D Maintenance Manual and Continental IO-470 Engine Operator’s Manual.

Text from the NTSB. Open the NTSB docket for CEN23FA173 for the full record.