N177AR

On March 27, 1999, about 2112 Eastern Standard Time, a Cessna 177RG, N177AR, was substantially damaged during a forced landing in Pottstown, Pennsylvania. The certificated private pilot was not injured. Visual meteorological conditions prevailed and no flight plan was filed for the personal flight conducted under 14 CFR Part 91.

The pilot stated that he had departed from the Reading Regional Airport, Reading, Pennsylvania, for a cross-country flight to Ocean City, New Jersey. During the climb, passing through 5,000 feet, the engine started to shake violently and lost power. The pilot was in contact with Philadelphia Approach Control, and advised them of a loss of power. The controller told the pilot that Pottstown Municipal Airport was located 5 miles southwest. The pilot turned towards the airport and began a descent. About 1 mile from the airport the pilot decided that he would not be able to make the runway and maneuvered for a forced landing. The airplane touched down on a two-lane highway, struck an overpass with the left wing, rotated 180 degrees, and came to rest upright in a ditch.

An inspection of the wreckage by the Federal Aviation Administration revealed the number 2 cylinder had separated from the engine and was lodged into the cowling. The engine was removed from the wreckage and disassembled under the supervision of NTSB personnel at Textron Lycoming, Williamsport, Pennsylvania, on June 24, 1999. Examination of the engine revealed sealant applied to the upper portion of the crankcase. The top crankcase fasteners were tested for torque, and began to turn before the specified 96-inch pounds recommended by the manufacturer. When the crankcase was split open, fretting to the parting surfaces was observed. The center main bearing exhibited signs of movement and fretting was observed on the bearing saddle. Fretting was also found on the number 2 and 3 cylinder flanges and corresponding crankcase decks.

The number 2 cylinder thru stud torque could not be determined due to missing nuts on the opposing side. When the thru studs were removed, heavy fretting was noted around the stud hole area on the crankcase parting surfaces. The thru stud diameter matched the recommended diameter as specified in the manufacturer service instruction (SI) No. 1029D.

The number 2-cylinder piston connecting rod and its associated components were not recovered after the accident. The oil sump and filter were inspected for debris. Only fragments consistent to a piston assembly were found.

Review of the engine logbook revealed that the engine had accumulated a total time of 1285 hours since it was last overhauled on July 14, 1994.

Entries in the engine logbook indicated that the top parting surface of the crankcase was resealed on February 7, 1997, November 20, 1998, and March 17, 1999. The last noted entry for tightening the crankcase bolts was on June 19, 1998. The number 2 and number 3 cylinder were last removed and replaced on April 2, 1997, by an overhaul facility.