Aviation Accident Summaries

Aviation Accident Summary DFW05LA083

Austin, TX, USA

Aircraft #1

N3870W

Beech 77

Analysis

The 5,797-hour pilot reported during cruise flight, he heard "a loud fluttering metallic sound" originating from the engine followed by the propeller stopping abruptly. The pilot initiated a forced landing into a nearby golf course. After touchdown, the pilot noted that due to the downhill slope, and wet grass, braking action was minimal. As the airplane crossed rising terrain near the green, the pilot applied full aft controls and the airplane became airborne. Subsequently, the airplane impacted trees and came to rest upright. Examination of the engine revealed that the number three cylinder connecting rod was separated from the crankshaft. The number three journal was gouged, scoured, and displayed evidence of heat distress. Small amounts of paper fiber, consistent with a shop towel were found throughout the engine crankcase, oil filter, and oil screen. An entry in the engine logbook indicated that the day prior to the accident, the crankshaft, lifters, oil pump impellers, and right magneto were replaced.

Factual Information

On March 8, 2005, approximately 1130 central standard time, a Beech 77 single-engine airplane, N3870W, registered to and operated by a private individual, sustained substantial damage during a forced landing following a loss of engine power near Austin, Texas. The commercial pilot and pilot rated passenger sustained minor injuries. Visual meteorological conditions prevailed and a flight plan was not filed for the 14 Code of Federal Regulations Part 91 personal flight. The cross-country flight originated from the Lago Vista Rusty Allen Airport, near Lago Vista, Texas, approximately 15 minutes prior to the accident and was destined for the Austin-Bergstrom International Airport (AUS), near Austin, Texas. The 5,797-hour pilot reported in the Pilot/Operator Aircraft Accident Report (NTSB Form 6120.1/2) that he did not notice any abnormalities during the preflight and engine run-up prior to takeoff. While in cruise flight at an altitude of 2,500 feet mean sea level (msl), the pilot and passenger noticed a 100 rpm drop on the engine tachometer. After verifying the throttle and mixture settings, the pilot heard "a loud fluttering metallic sound" originating from the engine followed by the propeller stopping abruptly. After scanning the area, the pilot elected to land in a nearby golf course. The pilot stated that during the emergency descent, he realized that the fairways of the golf course were obstructed by golf carts and immediately became concerned about the people located on the golf course. While on base leg for the sixth green, the pilot noticed that the green for the 10th hole appeared to be unoccupied. The pilot slipped the airplane with full flaps while attempting to land near the tee box. After touchdown, the pilot noted that due to the downhill slope, and wet grass, braking action was minimal. Nearing the green of the 10th hole, the pilot observed a line of trees directly in the path of the airplane. As the airplane crossed rising terrain near the green, the pilot applied full aft controls and the airplane became airborne. The pilot added that this was an attempt to hit the tops of the trees to cushion the impact. Subsequently, the airplane impacted trees approximately 20 feet above ground level and spun around 180-degrees before impacting terrain and coming to rest upright. Examination of the airplane by an Federal Aviation Administration (FAA) inspector, who responded to the accident site, revealed that the empennage was bent and rotated to the left and the leading edge of the right wing was crushed aft along its respective span. Fuel was observed in the right wing fuel tank. The left wing fuel tank was breeched. Examination of the Lycoming O-235-L2C engine by an FAA inspector was conducted on March 31, 2005, at the facilities of AIM Aviation, near Georgetown, Texas. No movement was observed from the number three piston when the propeller was rotated by hand and compression was noted on cylinders one, two, and four. The number three cylinder could not be removed. Removal of the number four cylinder revealed portions of a shop cloth under the number four journal. Visual inspection inside the crankcase revealed that the number three connecting rod was not attached to the crankshaft. A portion of the number three connecting rod, rod cap, and attach bolt were found wedged down into the crankcase. The number three journal was gouged, scoured, and displayed evidence of heat distress. Small amounts of paper fiber were found in the oil filter when it was removed and examined. The oil screen was removed and was observed covered with a material consistent with the shop cloth found in the crankcase. Review of the airplane engine logbooks revealed that the engine underwent recent maintenance on March 7, 2005. The logbook entry stated that the crankshaft, lifters, oil pump impellers, and right magneto were replaced.

Probable Cause and Findings

The loss of engine power due to the failure of the number three connecting rod. Contributing factors were the foreign object located within the engine lubrication system, inadequate inspection of the engine by other maintenance personal, and the lack of suitable terrain for the forced landing.

 

Source: NTSB Aviation Accident Database

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