What aircraft was involved and where did it happen?

The accident on 2003-06-15 involved an Enstrom 280C, registration N5695D, at West Branch, MI.

Helicopter engine failure leads to water impact (N5695D)

On June 15, 2003, an Enstrom 280C (registration N5695D) was involved in an aviation accident near West Branch, MI. Investigators recorded the probable cause as: A fatigue-type failure of the connecting rod cap led to a hole in the engine crankcase and subsequent loss of engine power. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.

A helicopter experienced a loss of engine power during its initial climb, resulting in an autorotative landing in shallow water.

What happened

During the initial climb phase, the pilot experienced a sudden loss of engine power. The pilot performed an autorotation, which resulted in the aircraft impacting the water approximately 75 feet from the shore. The helicopter landed upright in roughly 2.5 feet of water.

The investigation

An inspection of the aircraft confirmed that flight control continuity was maintained. Both fuel tanks were found to contain 25 gallons of fuel, and the engine contained 8 quarts of oil. Investigators found that the main and tail rotors showed drivetrain continuity. However, a large hole was discovered in the crankcase near the number one engine cylinder, with the number one connecting rod protruding through the opening.

Findings

Examination of the broken connecting rod cap revealed fracture features consistent with a fatigue-type failure. Additionally, investigators noted that the material surrounding the fatigue initiation point was galled, along with several other areas of the bearing interface.

Probable cause

A fatigue-type failure of the connecting rod cap led to a hole in the engine crankcase and subsequent loss of engine power.

2003-06-15: Enstrom 280C (N5695D) — West Branch, MI