Incident Overview
On June 22, 2015, about 0515 Pacific daylight time, a Piper PA-32R-301, registration N35590, experienced a total loss of engine power and subsequently landed on a beach of Lake Mead near Boulder City, Nevada. The aircraft was registered to an individual and operated by the pilot under 14 Code of Federal Regulations Part 91 as a personal flight. The pilot and three passengers were not injured, but the airplane sustained substantial damage. Visual meteorological conditions prevailed, and the flight operated on a visual rules flight plan. The cross-country flight originated from North Las Vegas Airport, Las Vegas, Nevada, around 0430.
Pilot Report
The pilot reported that about 20 minutes after takeoff, with the airplane leveled off at an altitude of about 7,500 feet mean sea level, the engine began to sputter. Attempting to regain continuous power, the pilot adjusted the mixture control to rich, but the propeller stopped spinning. Two attempts to restart the engine were unsuccessful. Subsequently, the pilot initiated a forced landing onto a nearby beach.
Examination Findings
The wreckage was examined at Air Transport, Phoenix, Arizona, on July 29, 2015, by representatives from Piper Aircraft, Inc., Lycoming Engines, and the Federal Aviation Administration under supervision of the National Transportation Safety Board investigator-in-charge.
Flight Controls and Airframe
Primary flight control cable continuity was established from the rudder and elevator control surfaces to the cockpit controls and to the wing roots from the yoke for aileron actuation cables. Post-accident examination of the airframe revealed no evidence of mechanical malfunctions or failures that would have precluded normal operation.
Engine Examination
The engine remained attached through all four mounts, hoses, wires, and control cables. All six cylinders remained attached. The two-blade variable pitch propeller remained attached to the crankshaft without damage. All engine accessories were attached, and all fuel and oil lines were intact and undamaged. The crankshaft could not be manually rotated using the propeller.
Upon disassembly, all six cylinders were undamaged, and the cylinder, valves, and rocker arms displayed normal operating and combustion signatures. All six piston faces showed normal signatures, and piston rings were undamaged and free to move. The crankshaft remained intact, and all connecting rods were free of heat distress.
The No. 1 and No. 2 crankshaft bearings exhibited heat signatures at the aft thrust face, with their respective crankshaft thrust surfaces showing significant coloration consistent with an elevated thermal event. Material transfer was present on the thrust surfaces at each end of the bearing, more predominant at the aft portion.
The oil filter was visually inspected and found free of contaminants or metallic material. The oil suction screen contained a few small pieces of non-ferrous metal particles. Laboratory examination of the No. 1 and No. 2 bearing halves showed substantial wear with missing Babbitt, exposing the underlying aluminum-tin intermediate layer. Black tint, scoring, and flowed metal were observed at the aft end of the No. 2 bearing interior, and metal particles from Babbitt were present at the chamfer at the forward edge of the No. 1 bearing.
Maintenance History
A review of maintenance records revealed that the most recent annual inspection was completed on July 24, 2014, at a total aircraft time of 3,136.18 hours and tachometer time of 1,718.68 hours. The last major overhaul was dated October 8, 1991, at a total aircraft time of 2,069.5 hours and tachometer time of 573.7 hours. The maintenance record indicated that bearings were replaced at that time but did not specify which bearings.