Aviation Accident Summaries

Aviation Accident Summary ATL04LA017

Carrollton, GA, USA

Aircraft #1

N4085H

Mooney M20K

Analysis

The flight was the airplane's first flight since the installation of a new engine. During cruise flight, the engine suddenly stopped producing power, and the propeller wind-milled. The pilot's attempts to restore engine power were unsuccessful. During forced landing to a small, uneven field, the airplane collided with the ground. Test bench examination of the magnetos and ignition harnesses revealed the components functioned to factory specifications. Test bench flow examinations of the throttle body fuel control, fuel pump, fuel manifold valve, lines and nozzles revealed the components functioned to factory specifications. Disassembly examination of the engine and accessories revealed no evidence of mechanical malfunction.

Factual Information

On October 13, 2003, about 1915 eastern daylight time, a Mooney M20K, N4085H, registered to and operated by the airline transport pilot, collided into an uneven field following a loss of engine power in the vicinity of Carrollton, Georgia. The personal flight was operated under the provisions of Title 14 CFR Part 91 with no flight plan filed. Visual meteorological conditions prevailed. The airline transport pilot received minor injuries, and the airplane sustained substantial damage. The local flight departed Lyons Landing private airstrip, Whitesburg, Georgia, about 1900 on October 13, 2003. The flight was the airplane's first flight since the installation of a new engine, and the pilot estimated the engine had accumulated four hours of ground operating time. The pilot stated the engine start, warm up, and run up were normal with fuel flow, oil pressure, and cylinder head temperatures within normal range. The pilot stated the takeoff and climbout were normal, and he maneuvered the airplane in the vicinity of the airstrip at 3,000 feet mean sea level. The pilot stated he flew the airplane west for a few minutes, then began a turn back toward the airstrip. He stated the engine suddenly stopped producing power, and the propeller wind-milled. The pilot's attempts to restore engine power were unsuccessful. The pilot located a small field for emergency landing. During approach to the field, the pilot maneuvered the airplane clear of trees and power lines, and the airplane collided with the uneven ground and skidded approximately 75 feet before coming to a stop. Examination of the airplane revealed the left wing was separated, the engine was separated from the firewall, and the right wing, fuselage, and empennage were damaged. Examination of the engine at a recovery facility revealed crush damage to the left and right exhaust pipes and damage to the propeller. Fuel retrieved from the gascolator appeared free of contaminants. The low-end fuel pressure adjustment screw lock-nut on the fuel pump was found loose. The damaged propeller was removed, a test propeller was installed, and the engine was supplied fuel and electrical power. The engine was started, and it ran rough with the mixture control near the idle cutoff position. The oil return line from the turbocharger was observed to leak, and the engine was shut down. The oil return line was repaired, and a second engine start was attempted with the mixture in the full rich position, and the engine would not start. The engine was shipped to Teledyne Continental Motors, Mobile, Alabama, for further examination. Dye penetrant examination of the crankshaft propeller flange revealed cracks on the aft flange radius. The cracks precluded a full diagnostic engine run in a factory test cell. Examination of the exhaust damage revealed the No. 6 riser was crushed, and crush damage restricted the exhaust flow area from the Nos. 2, 4, and 6 side of the engine and transition flow area to the Nos. 1, 3, and 5 side turbocharger assembly. Test bench examination of the magnetos and ignition harnesses revealed the components functioned to factory specifications. Test bench flow examinations of the throttle body fuel control, fuel pump, fuel manifold valve, lines and nozzles revealed the components functioned to factory specifications. Disassembly examination of the engine and accessories revealed no evidence of mechanical malfunction.

Probable Cause and Findings

A loss of engine power for undetermined reasons.

 

Source: NTSB Aviation Accident Database

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