CEN17FA266

The loss of engine power and the subsequent pilot's loss of control for reasons that could not be determined because post-accident engine examination revealed no anomalies.

The airline transport rated pilot and passenger departed on a cross-country business flight in a twin-engine, turbo-propeller-equipped airplane in day, visual meteorological conditions. Shortly after takeoff, the airplane banked left, descended, and impacted terrain about 1/2 mile from the end of the runway. There was not a post-crash fire and fuel was present on site. A postaccident airframe examination did not reveal any anomalies that would have precluded normal operation. Examination of the left engine found signatures consistent with the engine producing power at impact. Examination of the right engine revealed rotational scoring on the compressor turbine disc/blades, and rotational scoring on the upstream side of the power vane and baffle, which indicated that the compressor section was rotating at impact; however, the lack of rotational scoring on the power turbine disc assembly, indicated the engine was not producing power at impact. Testing of the right engine's fuel control unit, fuel pump, propeller governor, and over-speed governor did not reveal any abnormities that would have accounted for the loss of power. The reason for the loss of right engine power could not be determined based on the available information.

At 0753, the automated weather observation station (AWOS) located at TYR, recorded: wind from 120° at 4 knots, 10 miles visibility, a clear sky, temperature 79° F, dew point 74° F, and an altimeter setting of 29.97 inches of mercury. The pilot held an airline transport pilot certificate with ratings for airplane single- and multi-engine land and instrument airplane. He held type ratings for Boeing 737 and Falcon 10 airplanes. He also held a mechanic certificate with airframe and powerplant ratings. His Federal Aviation Administration (FAA) first-class medical certificate was issued on January 17, 2017, with the limitation that he, must wear corrective lenses. At the time of the medical exam, the pilot reported 17,590 total flight hours and 120 hours in the previous six months. The operator reported that the pilot routinely flew to MDD, that he also flew a business jet, and that this was first solo flight since receiving a checkout in the accident airplane. The on-site examination of the wreckage and ground scars revealed the airplane impacted the bank of a small pond about 1/2 mile from the end of runway 17. There was not a post-crash fire and fuel was present at the site. The airplane came to rest on its right side, on the edge of the pond; the front of the cabin displayed heavy impact damage. Both wings separated from the fuselage; the right wing was in the pond and just beyond the main wreckage, and the left wing was located under the main wreckage. The right engine separated from the nacelle and was located beside the right side of the wreckage; the four-bladed propeller remained attached to the engine. The left engine came to rest in front of the wreckage and its propeller was separated at the propeller shaft. The wreckage was recovered to a secure facility, for further examination. by the NTSB Investigator-in-Charge and technical representatives from the engine and airframe manufacturers. The left wing displayed substantial impact damage. The outboard 1/3 of the wing was impact-separated from the inboard portion. The aileron and outboard half of the flap were also impact-separated. The aileron control cable was secure to the bell crank and continuous to the wing root area. The balance cable was secure to the bell crank and continuous to the center fuselage area where it displayed an overload separation. The flap actuator showed about 1/2 thread, consistent with a retracted position. The left main landing gear was retracted. The left fuel valve was found in the open position. The cross-feed valve was found in the off position. The right wing was largely intact with both the aileron and flap in place. The aileron control cable was secure to the bellcrank and continuous to the wing root area where it had been cut for transport. The balance cable was secure to the bellcrank and continuous to the left side of the middle attach fitting, where it was overload separated. The right main landing gear was retracted in the wheel well but not secured by the up-lock. The flap actuator displayed about 1/2 thread, consistent with a retracted position. The aileron trim drum inner shaft aft extension was about 1/2 thread, consistent with a tab position of full up about 15°. The right fuel valve was found in the open position. The horizontal stabilizer and elevator displayed substantial impact damage and were separated for transport. The elevator control cables were secure to the elevator bellcrank and continuous to the elevator sector in the cockpit. The elevator trim drum displayed 3 threads aft extension of the inner shaft consistent with a setting of about 3° degrees trailing edge down, (nose up), pitch trim. The rudder was secure and free to move through full travel. The rudder cables had been cut for recovery transport forward of the rudder sector but were continuous to the forward cockpit. The rudder trim drum inner shaft forward extension had about 9.5 threads showing, consistent with a neutral setting. The fuselage had substantial impact damage to the nose and cockpit areas. The engine control levers were found in the forward positions. The rudder trim was set at the neutral position. The landing gear lever was in the retracted position. The flap lever was in the full up (retracted) position. Both handles were broken from the pilot's control wheel. The fuel controls were both in the "ON" position and the cross feed was in the "OFF" position and corresponded to the positions at the fuel valves. No airframe anomalies were noted that would have precluded normal operation. Left Engine The left engine's four-bladed propeller shaft had fractured, separating the propeller from the engine. The blades exhibited twisting, polishing, and bend signatures. The exhaust duct displayed compressional bending and was torn from impact with terrain. The left exhaust stack was impact separated from the exhaust duct. The gas generator case displayed compressional bending. The engine was separated at the "C" flange to expose the hot section components. The downstream face of the compressor turbine disc and blades exhibited rotational scoring from contact with the power turbine vane. The upstream side of the compressor turbine blades displayed rotational scoring from contact with the compressor turbine vane. The power turbine vane and baffle exhibited rubs on the upstream side from contact with the compressor turbine disc. The downstream side of the vane and the baffle exhibited rotational scoring from contact with the power turbine disc. The power turbine disc and blades exhibited rotational scoring on the upstream and downstream sides from contact with the adjacent static components. Several first stage compressor blades exhibited impact damage. Right Engine The right engine's four-bladed propeller remained attached to the propeller shaft. The blades exhibited varying degrees of bends. The exhaust duct displayed compressional bending due to impact with the terrain. The left exhaust stack was bent and distorted. The gas generator case displayed compressional bending. The inlet case struts were all fractured. The engine was separated at the "C" flange to expose the hot section components. The downstream face of the compressor turbine disc and blades exhibited rotational scoring from contact with its respective adjacent static components. The upstream face of the compressor turbine disc and blades were unremarkable. The power turbine vane and baffle exhibited rubbing on the upstream side from contact with compressor turbine disc. The downstream side vane and baffle exhibited static impact marks from contact with the power turbine disc and blades. The power turbine disc and blades exhibited impact marks on the upstream and downstream side from contact with the adjacent static components. Several blades were fractured and displaced forward in the disc fixings. The accessory gearbox was manually rotated by hand, and mechanical continuity was established through the gears. The wire bundles on the engines were in poor condition, with bare metal showing in some sections. Several components were removed from the right engine and shipped to P&W Canada for testing under the observation and guidance of the Transportation Safety Board of Canada. The fuel control unit, the fuel pump, propeller governor, and over-speed governor were tested and disassembled. Testing of the fuel pump indicated that the pump performance was satisfactory. Observations recorded during testing of the overspeed governor indicated that the speed pick-up voltage was below the test point minimum limit;. however, the tests on the components did not identify any abnormalities that would have explained a loss of engine power. The accident airplane was a Piper Cheyenne, PA-31T, which is a low-wing, twin-engine airplane, with retractable, conventional landing gear, powered by two Pratt &