Moscow, PA, USA
N618G
Lancair LC41
The pilot reported that, about 20 minutes after departure, the airplane began to shudder. He adjusted the engine power, but the airplane continued to shake before the engine lost total power. The pilot performed a forced landing to a road, during which the airplane sustained substantial damage. Visual examination revealed multiple holes in the top of the engine crankcase. Disassembly of the engine revealed that the Nos. 2, 3, 4, and 5 connecting rods were fractured and separated from the connecting rod journals. The connecting rods, connecting rod bearings, and the crankshaft’s connecting rod journals displayed thermal discoloration consistent with oil starvation. Examination of the engine components and engine-related systems revealed no evidence of a pre-impact oil leak; however, the left turbocharger was missing its turbine wheel, and the shaft was fractured outboard of the turbine piston ring. A test run of an exemplar engine without the left turbine wheel revealed significant oil loss during operation. The left turbocharger was overhauled 158 flight hours before the accident, and its wheel assemblies were reused rather than replaced, as specified by the manufacturer. It is likely the separation of the left turbine wheel resulted in oil escaping the engine, which resulted in oil starvation and catastrophic engine failure.
On December 4, 2018, about 1045 eastern standard time, a Lancair LC41, N618G, was substantially damaged during a forced landing following a loss of engine power near Moscow, Pennsylvania. The private pilot was not injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight. The pilot stated that, about 20 minutes after departure, the airplane shuddered. He adjusted the engine power, and the airplane shook again. He advised air traffic control that he was having engine trouble and was given a heading to a nearby airport; however, the engine continued to shake, and the pilot reported that there was smoke in the cockpit. About one minute later, the engine lost total power and the pilot performed a forced landing to a road. A Federal Aviation Administration inspector examined the airplane and noted substantial damage to the left wing and multiple holes in the top of the engine crankcase. Further examination revealed thermal damage on the induction tubes and the magnetos in areas that coincided with some of the holes. Portions of separated connecting rods were observed through the holes in the case. The Nos. 2, 3, 4, and 5 connecting rods were fractured and separated from the connecting rod journals. The connecting rods, connecting rod bearings, and the crankshaft’s connecting rod journals displayed thermal discoloration consistent with oil starvation. Examination of the engine components and engine-related systems revealed no evidence of a pre-impact oil leak; however, the left turbocharger was missing its turbine wheel and the shaft was fractured outboard of the turbine piston ring. The exhaust system was unremarkable with the exception of the missing left turbocharger turbine. The exhaust shroud showed some signs of turbine contact when it exited the exhaust system. The oil sump remained secured to the bottom of the engine, and there were no signs of an oil leak from the sump area. Removal of the sump revealed that it was filled with fractured engine core components. The left turbocharger’s turbine wheel was missing and there was little to no rub or contact damage noted on the turbine wheel housing. Examination of the left turbocharger shaft revealed scoring and corrosion pitting. The turbine wheel of the right turbocharger remained attached. A test engine run was used to demonstrate the result of a turbine wheel failure. An exemplar engine without the left turbine wheel was placed in a test cell and lost about 5 quarts of oil in about 2 minutes; oil was observed streaming out of the exhaust pipe. Overhaul Maintenance History In May 2016, the engine was overhauled at an engine total time of 1,115.2 hours. When the engine was reinstalled after the overhaul, it was equipped with turbochargers that were manufactured in 2004 and overhauled by Approved Turbo Components, Inc. in April 2016. During the turbocharger overhaul, the right turbocharger shaft was reused. The left turbocharger shaft was replaced with a reused shaft from a 2008 turbocharger. The turbine wheel assemblies from the left turbocharger did not meet the criteria to be reused and were not replaced with a new assembly as specified in the Turbocharger Overhaul Manual, 400600-0000 Rev B.
A total loss of engine power and catastrophic engine failure due to the failure of the left turbocharger, which resulted in oil loss and oil starvation. Contributing to the accident was the failure of maintenance personnel to overhaul the turbocharger in accordance with manufacturer guidance.
Source: NTSB Aviation Accident Database
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