Aviation Accident Summaries

Aviation Accident Summary CHI95LA284

DECKER, IN, USA

Aircraft #1

N69VZ

VAN ZWOLL VIKING

Analysis

THE PILOT WAS CRUISING AT 2,000 FEET MEAN SEA LEVEL AND NOTED THE WATER PRESSURE GAGE WAS PEGGED AT THE MAXIMUM INDICATION. HE IMMEDIATELY REDUCED POWER AND BEGAN SEARCHING FOR AN EMERGENCY LANDING SITE. HE HEARD A 'LOUD POP' AND OBSERVED COOLANT ON THE WINDSCREEN. THE OIL TEMPERATURE INDICATION BEGAN TO INCREASE. HE TRIMMED FOR BEST GLIDE AND SHUT THE ENGINE DOWN WHEN THE OIL TEMPERATURE REACHED 285 DEGREES. DURING THE FORCED LANDING IN A CORN FIELD, ONE OF THE LIFT STRUTS SUSTAINED SUBSTANTIAL DAMAGE. EXAMINATION OF THE ENGINE REVEALED THAT ONE OF THE HEAD GASKETS WAS LEAKING AND COOLANT WAS ESCAPING FROM A LEAKING FREEZE PLUG. THE PILOT REPORTED THAT THE MANUFACTURER'S TORQUE PROCEDURE WAS FOLLOWED WHEN HE INSTALLED THE HEAD.

Factual Information

On August 10, 1995, at 1250 central daylight time, an experimental Van Zwoll Viking, N69VZ, sustained substantial damage during a forced landing near Decker, Indiana. The commercial pilot reported no injuries. The personal, 14 CFR Part 91 flight originated in Evansville, Indiana, at 1230, with a planned destination of Mount Carmel, Illinois. Visual meteorological conditions prevailed and no flight plan was filed. The pilot reported he was cruising at 2,000 feet mean sea level. He noted the water pressure gage was pegged at the maximum indication. He immediately reduced power from 4,000 rpm to 2,500 rpm and began searching for an emergency landing site. He heard a "loud pop" and observed coolant on the windscreen. The oil temperature indication began to increase. He trimmed for best glide and shut the engine down when the oil temperature reached 285 degrees. He reported that he searched for an emergency landing site and the best location appeared to be a corn field. During the landing, one of the lift struts sustained substantial damage. Examination of the engine revealed that one of the head gaskets was leaking and coolant was escaping from a leaking freeze plug. The pilot reported that the manufacturer's torque procedure was followed when he installed the head.

Probable Cause and Findings

the failure of the head gasket resulting in a coolant leak and subsequent engine overtemperature. A factor was the unsuitable terrain encountered in the cornfield.

 

Source: NTSB Aviation Accident Database

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