Cessna 310 N5045Q accident near Fayetteville, Tennessee

Probable cause

The pilot’s decision to operate the airplane with known discrepancies.

NTSB analysis

The pilot, who was also a mechanic, purchased the twin-engine airplane nearly one year prior to the accident flight. Between the time of purchase and the accident flight he had performed some maintenance of the airplane’s engines; however, the airplane had not undergone an annual inspection at any point during the preceding 15 years, nor had the pilot obtained a special flight (ferry) permit for the accident flight. Prior to departing, the pilot performed an engine runup and noted a substantial rpm drop during the right engine magneto check. He also described that he leaned both engines’ mixture controls for takeoff due to the density altitude, and because both engines would “flood out” and not run with the mixture controls in the fully forward position. During initial climb the pilot reported the airplane seemed “sluggish,” so he advanced the mixture controls forward, after which both engines lost partial power. The pilot then decreased the airplane’s pitch attitude and landed in the grass next to the runway, which resulted in substantial damage to both wings and the fuselage.

A postaccident examination of the airplane’s engines found contamination in the fuel system for the right engine. The fuel manifold valve was corroded and the fuel servo inlet screen and fuel manifold screen for the right engine were partially obstructed. Multiple spark plugs installed in the right engine exhibited corrosion, lead, and carbon fouling, and severe wear. The right engine air intake hose was found disconnected from the airbox. This condition would have likely resulted in the engine ingesting warm, unfiltered air from the cowling instead of cooler, filtered ram air. The combination of these issues likely resulted in the feeling of diminished performance the pilot reported.

The examination otherwise found no evidence of any preaccident mechanical malfunctions or failures of the left engine or the airframe that would have precluded normal operation.

Given the pilot’s statement that the engines would “flood out” and would not run with the mixture controls in the full forward position, it is likely that when the pilot advanced the mixture controls during initial climb the increased fuel flow resulted in the partial loss of power the pilot reported. Because this abnormal condition was known prior to the accident flight, the pilot should not have undertaken the flight without performing additional troubleshooting steps to fully understand and resolve the underlying issue(s).

Text from the NTSB. Open the NTSB docket for ERA25LA238 for the full record.