Hudson, FL, USA
N6420M
Cessna 152
The pilot was in cruise flight at 2,300 feet looking at a map when he heard a noise and the sound of the engine changed. He looked out, noticed the slow movement of the propeller blades and observed the tachometer dropping to zero. He declared an emergency on guard frequency and initiated a forced landing. He observed a golf course and headed towards it. On approach he determined that the golfer's would be in the way so he transitioned the forced landing towards a road. On landing rollout the left wing hit a sign. Examination of the engine assembly revealed the crankcase center web mating surface exhibited severe fretting. The crankshaft center main bearing was found displaced aft at the same location, and the bearing half's were partially rotated out of the normal position. The bearing's displaced position blocked the oil supply hole that furnishes lubrication oil to the No. 3 connecting rod and the No.3 connecting rod failed due to oil starvation. Review of aircraft logbooks revealed the engine had exceeded the manufactures recommended time before overhaul.
On February 25, 2002, about 0900 eastern standard time, a Cessna 152, N6420M, registered to Jensen Aviation Inc., operating as a 14 CFR Part 91 instructional flight experienced a loss of engine power in cruise flight. The airplane collided with a fixed object during a forced landing to unsuitable terrain. Visual meteorological conditions prevailed and no flight plan was filed. The airplane sustained substantial damage. The student pilot was not injured. The flight originated from Tampa, Florida, about 0850. The pilot stated he was in cruise flight at 2,300 feet looking at a map. He heard a noise and the sound of the engine changed. He looked out, noticed the slow movement of the propeller blades and observed the tachometer dropping to zero. He set the power to idle and smoke and oil was observed. He declared an emergency on guard frequency and initiated a forced landing. He observed a golf course and headed towards it. On approach he determined that the golfer's would be in the way so he transitioned the forced landing towards a road. On landing rollout the left wing hit a sign. Examination of the airplane by the FAA and the engine manufacturer revealed a hole in both tops of the engine case halves in the vicinity of the No.3 and No. 4 cylinder with a broken connecting rod sitting in the hole. The engine manufacture stated, "The engine was partially disassembled. The oil suction screen and oil filter element contained small size metal particles. The cylinder top end components were intact and exhibited no pre-impact anomalies. The rear accessory components, magnetos and vacuum pump were checked for security and were found intact. The rear case was removed and the accessory drive gears were intact. The oil pump was inspected and the steel impeller gears were intact. Rotational scoring was observed inside the walls of the oil pump housing. The oil pressure relief valve assembly appeared normal. The powersection (Crankcase) was opened, and the crankshaft, camshaft, and connecting rods were inspected. The crankcase center main bearing was found displaced aft at the same location, and all bearing half's were partially rotated out of normal position. As found the bearing's displaced position blocked the oil supply hole that furnishes lubrication oil to the No. 3 connecting rod. The broken remains of the No.3 connecting rod exhibited heat distress, and the bearing remains were extruded, slivered, essentially destroyed. The No. 4 connecting rod was found broken, however, the parts displayed signs overload separation, no evidence of overheat, or lack of lubrication was noted." (for additional information see, Textron Lycoming Air Safety Investigation Single Engine Aircraft Mishap Final Report an attachment to this report.) Review of aircraft logbooks revealed the last recorded engine overhaul was on March 2, 1994, at engine total time of 6,342.3 hours. At the time of the accident the engine had accumulated 3,278.5 hours since the overhaul. Review of 14 CFR Part 43.13 (a) states, "Each person performing maintenance, alteration, or preventive maintenance on an aircraft, engine, propeller, or appliance shall use the methods, techniques, and practices prescribed in the current manufacture's maintenance manual or instruction for continued airworthiness prepared by its manufacturer, or other methods, techniques, and practices acceptable to the administrator, except as noted in 43.16. Review of Textron Lycoming Service Instruction No. 1009AQ states the appropriate recommended time before overhaul for the engine is 2,400 hours.
Total loss of engine power due to oil starvation to the No. 3 connecting rod preceded by aft displacement of the center main bearing due to excessive wear. This resulted in a forced landing to none suitable terrain and subsequent on-ground collision with a road sign. Factor to the accident was the company operator management decision to exceed the manufactures recommended time before overhaul
Source: NTSB Aviation Accident Database
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