19980609012829A

Pilot declared emerg, cleared to land on rwy 20, acft lost engine, struck power lines and crashed. (.4)the pilot-in-command reported a power loss on approach to the runway. The aircraft passed through the tops of trees approximately 150 feet beyond, and entered a stall/spin maneuver, impacting a power line and the ground approximately 2,800 feet short of the runway threshold. The flaps and landing gear were in a retracted position. Post-crash examination revealed the crankshaft separated in fatigue which originated from a circumferential gouge mark on the aft face of the #2 cheek at an area located outboard of the forward radius of the #1 rod journal. The circumferential gouge mark on the crankcheek was consistent with the connecting rod shifting forward during engine operation. The rub marks on the cheek walls of the #1 connecting rod were consistent with tight piston pin bushing to piston pin clearance. Additionally, the bushings for all the connecting rods were undersize. Airframe/engine logs revealed a top overhaul of the engine approximately 23 hours prior to the crankshaft failure, during which the piston pins were replaced b ut the connecting rod bushings were not. No dimensional check of the bushings was made or required at that time. The engine was overhauled 515 hours previous to the top overhaul. The manufacturer's overhaul maual specifies that the new bushings should be reamed to the specified (inside) diameter. Post-crash examination of the engine revealed non-standard connecting rod cotter keys and light fretting between the engine case halves. (-23) on this date at approximately 13:00 pm, a Cessna 210 piloted by joseph r. burtla and one female passenger possibly, Mr. Shirley burtla, crashed 1/4 mile short of runway 30 at the Hillsboro Oregon airport. The pilot had declared an emergency and was cleared to land on runway 20. The Hillsboro control tower asked the nature of the emergency. The pilot responded that his engine had failed. While approaching runway 30 the aircraft struck a tree, which was approximately 6 inches in diameter. After the tree contact, approximately 300 feet beyond, the aircraft's vertical stabilizer made contact with a power line. The aircraft did not break the power line, but made a near vertical descent to the ground exploding into flames and burning. Both occupants of the aircraft received fatal injuries. Examination of the wreckage disclosed that the cockpit area had been burned, two adult charred bodies were located in that area. Further examination of the wreckage suggests possible engine problems. NTSB will have the engine shipped to the factory for analysis.