CHI96TA306

The pilot stated that he was in cruise flight when he heard a loud noise and the helicopter yawed to the left. He initiated an autorotational landing into a residential area where the helicopter impacted trees and the terrain. An examination of the engine found two pieces of plastic in the induction tubes. The pieces were found to have come from the induction housing, but the reason for the fracture was not determined. The two pieces fitted together and could be positioned to block the fuel injection control.

On August 19, 1996, at 1804 central daylight time, a Hughes 269A, N7052A, sustained substantial damage during an autorotational landing following a loss of engine power in cruise flight. The pilot stated the engine stopped suddenly after a loud "pop." The accident occurred in the City of Cedar Rapids, Iowa. The flight was a public use operation by the Cedar Rapids Police Department. The flight was being conducted in visual meteorological conditions. No flight plan was on file. The pilot reported minor injuries. The local flight departed Cedar Rapids about 1730.

The pilot stated that he was on a routine police patrol and was responding to a call in the southeastern part of the city. He said he was cruising at an altitude of about 1,400 feet mean sea level, in level flight when he heard a loud noise and the helicopter yawed to the left. He stated that he immediately lowered the collective control and initiated an autorotational landing. He found he was over a residential area and selected two trees which turned out to be about three to three and one half inches in diameter and measured by the police depart, to be 26 feet tall. The main rotor system impacted the trees and the helicopter continued to the ground. The pilot stated that the engine was not running during the forced landing.

An examination of the engine from the accident helicopter was conducted on September 4, 1996. The engine was test run. The engine ran within manufacturer's specification during the examination. The report of the examination is attached to this report.

During the preparation for the engine run the #3 and #4 induction tubes were removed for replacement, due to impact damage. Inside each tube was one piece of plastic. When placed together the two pieces fit together. The inlet induction housing was inspected and the pieces were determined to be from that housing. There were several splits in the housing in the area where the plastic pieces originated. The reason for their separation was not determined. It was possible to lay the two pieces over the fuel control induction unit and block the air tubes. See photos attached to this report.