CHI94LA332

While en route, the pilot heard a repetitive loud knocking sound from the engine. The exhaust gas temperature gage showed a rapid drop, and the engine began to surge. Unable to maintain altitude, the pilot elected to make an emergency landing. An extremely loud bang was then heard, and the upper part of the cowling blew open and back toward the windshield. The pilot switched the fuel selector to the off position, closed the throttle, pulled the mixture control to idle cut-off, and made a forced landing on a road. During the landing roll, the right wing struck a pole which was located on the side of the road. Postaccident examination revealed the #2 cylinder had fractured. Corrosion was visible on the fracture surfaces. Maintenance records showed that the cylinder was replaced with a reconditioned cylinder at the last annual inspection on 5/1/94. The airplane had logged 65 hrs since the inspection.

On September 18, 1994, at 1545 central daylight time, a Cessna 170, N4216V, sustained substantial damage following a loss of engine power and subsequent forced landing on a road in St. Anne, Illinois. The pilot reported no injuries. The 14 CFR Part 91 personal flight departed Green County, Ohio, at 1300 with an intended destination of Kankakee, Illinois. The flight operated in visual meteorological conditions without flight plan.

In a written statement, the pilot reported that while approximately 20 miles from Kankakee, he heard a repetitive loud knocking sound from the engine. The exhaust gas temperature gauge showed a rapid drop and the engine began to surge. The pilot was unable to maintain altitude. The pilot stated he then heard an extremely loud bang and the upper part of the cowling blew open and back towards the windshield. He turned the fuel selector to the off position, closed the throttle, and pulled the mixture to idle cut-off. The pilot made a forced landing on a road. During the landing roll, the right wing struck a telephone pole which was located on the side of the road.

Postaccident examination revealed the number two cylinder had fractured mid barrel. Corrosion was visible on the fractured surfaces. Maintenance records for the airplane indicate the number two cylinder was replaced by a reconditioned cylinder at the last annual inspection performed on May 1, 1994. The airplane had logged 65 hours since the inspection.