Engine Failure Forces Wheels-Up Landing on Snow-Covered Highway (N6179N)

Incident Overview

Shortly after takeoff, the pilot of a single-engine aircraft heard a 'clunk' and subsequently lost manifold pressure. In response, the pilot reversed course back to the airport but was unable to reach the runway and was forced to land on a snow-covered highway. The pilot elected to land with the landing gear retracted (wheels up).

Engine Examination

Following the incident, an engine disassembly was conducted. The examination disclosed that the No. 1 connecting rod had broken at the crankshaft end. Additionally, the oil journal was completely blocked with babbitt (bearing material). Further inspection revealed evidence of lack of lubrication and high heat distress throughout the engine.

Findings

• The No. 1 connecting rod fractured at the crankshaft end.
• The oil journal was entirely obstructed by babbitt.
• The engine showed signs of inadequate lubrication and thermal stress.

The exact sequence of events leading to the blockage and subsequent rod failure was not specified in the investigation report.