Aviation Accident Summaries

Aviation Accident Summary FTW96LA061

EADS, CO, USA

Aircraft #1

N735JN

CESSNA 182Q

Analysis

WHILE IN NIGHT CRUISE VFR FLIGHT, THE PILOT HEARD A LOUD NOISE AND THE ENGINE LOST POWER. THE AIRPLANE SUSTAINED SUBSTANTIAL DAMAGE DURING THE ENSUING FORCED LANDING. ENGINE DISASSEMBLY DISCLOSED THE NUMBER 2 CYLINDER HAD SEPARATED FROM THE CRANKCASE AND THE PISTON WAS FRACTURED IN TWO PIECES. THERE WAS EVIDENCE OF CYLINDER ROCKING AND FRETTING. ONE THROUGH-BOLT PENETRATED THE COWLING, FOUR STUDS WERE BENT AND TWO STUDS WERE MISSING. ONE OF THE CONNECTING ROD BOLTS WAS STRIPPED AND THE OTHER HAD FAILED IN TENSION. THE NUMBER 5 CYLINDER WAS SCORED AND THE PISTON WAS ERODED. THERE WAS EVIDENCE OF HIGH HEAT DISTRESS. THE ENGINE WAS OVERHAULED IN JANUARY 1992, AND RECEIVED A PROPELLER STRIKE INSPECTION 7 MONTHS LATER. ENGINE TOTAL TIME WAS 3,301 HOURS, AND TIME SINCE MAJOR OVERHAUL WAS 1,498 HOURS.

Factual Information

On November 30, 1995, approximately 2250 mountain standard time, a Cessna 182Q, N735JN, was substantially damaged when it collided with terrain during a forced landing near Eads, Colorado. The private pilot sustained minor injuries. Night visual meteorological conditions prevailed at the time. No flight plan was filed for the business flight, conducted under Title 14 CFR Part 91. The flight originated at Englewood, Colorado, on November 30, 1995, approximately 2210. The following is based on the Pilot/Operator Aircraft Accident Report. The airplane was en route to Lamar, Colorado, in cruise flight between the Hugo VORTAC and Haswell, Colorado, when the pilot heard a loud noise and the engine lost power. The pilot declared an emergency with the Denver Automated Flight Service Station and Denver Air Route Traffic Control Center. The pilot was vectored towards the airport at Eads, Colorado, but was unable to sustain the glide for that distance. He executed a forced landing in a field and, during the landing roll, collided with rough and uneven terrain, damaging the nose landing gear, firewall, and keel. Engine examination disclosed the number 2 cylinder had separated from the crankcase. Engine disassembly revealed particles of piston, rod bolts and cap, rod bearing, lifter, and a piece of crankcase at the bottom of the oil sump. Some metal pieces were found in the oil pickup screen. One through-bolt penetrated the cowling; another bent the cooling fins on number 3 cylinder. Four studs were bent and two studs were missing. The studs were of two different sizes: 2-1/8 inches and 1-1/4 inches. The overhaul manual indicates the studs should be 1-1/2 inches. Closer examination disclosed evidence of cylinder rocking and fretting. The piston was fractured in two pieces, and the dome was gouged and dented. The rings and pin were not recovered. The rod had separated from the crankshaft. One of the rod bolt nuts was stripped; the other nut had fractured in tension. The spark plug was oil soaked. Examination of number 5 cylinder and piston disclosed extensive scoring on one side. There was evidence of heat distress on the piston and around the exhaust valve. Edges of the piston dome were eroded, and the rings were welded in their grooves. The piston pin was jammed in the piston, and the bushing had started to elongate. The cylinder walls were dry, and the connecting rod was discolored. The bearings were scored. The spark plug was packed with debris, and the helicoil was found extended into the combustion chamber. Examination of the engine maintenance records disclosed that the engine had been overhauled on January 15, 1992. Between August and October 1992, the engine was given a propeller strike inspection. At the time of the accident, engine total time was 3,301 hours, and 1,498 hours had elapsed since the engine was last overhauled.

Probable Cause and Findings

FAILURE OF THE ENGINE CONNECTING ROD BOLTS AND SEPARATION OF THE CYLINDER FROM THE CRANKCASE. FACTORS WERE THE LACK OF SUITABLE TERRAIN FOR THE FORCED LANDING, AND REDUCED LIGHT CONDITIONS (DARK NIGHT).

 

Source: NTSB Aviation Accident Database

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