Accident Overview
On December 4, 2018, at about 1045 eastern standard time, a Lancair LC41, registration N618G, was substantially damaged during a forced landing following a loss of engine power near Moscow, Pennsylvania. The private pilot was not injured. The flight was operated under Title 14 Code of Federal Regulations Part 91 as a personal flight.
Sequence of Events
According to the pilot, about 20 minutes after departure, the airplane shuddered. After adjusting engine power, the airplane shook again. The pilot advised air traffic control of engine trouble and was given a heading to a nearby airport. The engine continued to shake, and the pilot reported smoke in the cockpit. Approximately one minute later, total engine power was lost, and the pilot performed a forced landing to a road.
Examination Findings
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. Thermal damage was found on the induction tubes and magnetos coinciding with some holes. Portions of separated connecting rods were observed through the holes. The Nos. 2, 3, 4, and 5 connecting rods were fractured and separated from the connecting rod journals. The connecting rods, bearings, and crankshaft journals displayed thermal discoloration consistent with oil starvation.
No evidence of a pre-impact oil leak was found; 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 except for the missing left turbocharger turbine. The exhaust shroud showed signs of turbine contact when it exited the system. The oil sump remained secured and contained no signs of leak, but when removed, it was filled with fractured engine core components.
Turbocharger Failure
The left turbocharger’s turbine wheel was missing with little to no rub or contact damage on the turbine housing. Examination of the left turbocharger shaft revealed scoring and corrosion pitting. The right turbocharger’s turbine wheel remained attached.
A test engine run demonstrated the result of a turbine wheel failure: an exemplar engine without the left turbine wheel lost about 5 quarts of oil in about 2 minutes, with oil streaming out of the exhaust pipe.
Maintenance History
In May 2016, the engine was overhauled at an engine total time of 1,115.2 hours. During reinstallation, turbochargers manufactured in 2004 were fitted, overhauled by Approved Turbo Components, Inc. in April 2016. During that 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 criteria for reuse and were not replaced with a new assembly as specified in the Turbocharger Overhaul Manual, 400600-0000 Rev B.