CEN13LA195

The flight instructor reported that the purpose of the flight was to practice engine failure procedures and power-off approaches. The accident occurred during the third approach of the flight as he was demonstrating the power-off approach technique. He noted that he had climbed to 3,500 feet, reduced engine power, and began a spiral over the airport to enter the left traffic pattern to the runway. During final approach, the airplane started descending at a higher rate. The flight instructor stated that he attempted to increase engine power but that he did not "hear or feel an indication of [engine] power increasing." The airplane subsequently impacted terrain about 165 feet short of the runway. Flight and engine data recovered from the avionics were consistent with a power-off approach. The engine gas generator speed, torque, interturbine temperature, and oil pressure parameters were stable at the end of the recorded data and were consistent to the same parameters recorded during the initial power-off approach. A postaccident examination of the airframe and engine did not reveal any anomalies consistent with an inability to obtain engine power. Functional testing and subsequent teardown examinations of the fuel pump, fuel control unit, and fuel oil heat exchanger also did not reveal any anomalies that would have precluded normal operation. Variations from standard production component settings were consistent with field adjustments.

On March 13, 2013, at 1040 central daylight time, a New Piper Aircraft model PA-46-500TP airplane, N665KC, was substantially damaged when the airplane impacted short of runway 34 (6,002 feet by 75 feet, asphalt) at the Brenham Municipal Airport (11R), Brenham, Texas. The pilot, flight instructor, and passenger were not injured. The airplane sustained substantial damage to the fuselage and wings. The airplane was registered to and operated by N665KC, LLC, under the provisions of 14 Code of Federal Regulations Part 91 as a personal flight. Visual meteorological conditions prevailed for the flight, which was not operated on a flight plan. The flight originated from the West Houston Airport (IWS), Houston, Texas at 1000. The flight instructor reported that the purpose of the flight was to practice engine failure procedures and power-off approaches. The accident occurred during the third approach of the flight. The initial power-off approach necessitated a go-around and the second approach was terminated in a full-stop landing. On the third approach the flight instructor was demonstrating power-off approach technique. He noted that he had climbed to 3,500 feet, reduced engine power, and began a spiral over the airport for left traffic to runway 34. During the final approach, the airplane started descending at a higher rate. The flight instructor stated that he attempted to increase engine power, but he did not "hear or feel an indication of [engine] power increasing." The airplane subsequently impacted the terrain short of the runway. Ground marks were consistent with the airplane impacting about 165 feet short of the runway. The airplane ultimately came to rest on the runway pavement oriented on south heading. Both main landing gears separated during the accident sequence. The fuselage remained intact; however, the lower fuselage skin exhibited scraping damage aft of the passenger door. Both the left and right wings exhibited damage consistent with ground impact. Flight and engine data were recovered from the avionics units installed in the airplane. The flight data indicated that after the initial takeoff, the airplane climbed to approximately 6,000 feet pressure altitude. About 1015, a descent began that continued uninterrupted until the go-around. About 1019, the flight data indicated initiation of a climb to about 3,200 feet pressure altitude. A second descent was initiated about 1025, which terminated about 1029. Airspeed and altitude data during that timeframe were consistent with a full stop landing. The flight data indicated that the final, accident takeoff was initiated about 1033. The airplane climbed to approximately 3,200 feet pressure altitude and reached a maximum airspeed of about 160 knots. At 1037, immediately after reaching an approximate pressure altitude of 3,300 feet, a descent was initiated. During the descent, the airspeed varied between about 100 knots and 120 knots; the rate of descent varied between about 125 feet perminute (fpm) and 250 fpm. About 1040:10 (hhmm:ss), the flight data noted an abrupt change in heading from about 350 degrees to 170 degrees which was consistent with ground impact. Recorded airspeed data decreased from about 90 knots to zero during that time. Recorded engine data indicated a reduction in propeller speed beginning about 1039:00, from about 2,000 rpm to 1,700 rpm. During this timeframe, the engine torque and gas generator speeds decreased from about 150 foot-pounds to about 30 foot-pounds and from about 80 percent to about 65 percent, respectively. The profile of this reduction appeared similar to the propeller speed profile that began about 1015, apparently in conjunction with the initial simulated power-off approach. The gas generator speed, torque, inter-turbine temperature, and oil pressure parameters were stable at the end of the recorded data. A postaccident examination of the airframe and engine did not reveal any anomalies consistent with an inability to obtain engine power. The propeller assembly and engine cowling appeared intact with no observed propeller blade damage. The engine housing, installed components, fuel and pneumatic lines appeared intact with no observed discrepancies. The engine rotated freely. A borescope examination did not reveal any evidence of internal blade damage. Engine control continuity was confirmed. The power lever reverse lockout was functional at the time of the examination. Normal operation of the electric fuel boost pump was confirmed. The fuel bowl, fuel lines, and fuel filter were unremarkable. Recovered fuel appeared clean and free of sediment or contaminants. Functional testing and subsequent teardown examinations of the fuel pump, fuel control unit, and fuel oil heat exchanger did not reveal any anomalies. Variations from standard production component settings were consistent with field adjustments. At the time of the accident, the airplane had accumulated 734.7 hours total time. A review of the maintenance logbooks revealed that the most recent annual inspection was completed on January 30, 2013, at 725.3 hours total airframe time. At that time, the engine had accumulated 725.3 hours since new, with 583 cycles. An engine borescope inspection was completed on February 12, 2013, at 726.0 hours engine time, with no anomalies noted. The Pilot's Operating Handbook (POH) noted that in the case of an engine failure in-flight an airspeed of 108 knots should be maintained, with the power lever at idle, the condition lever at cut-off, and the propeller feathered. Regarding a maximum range descent after an engine failure, the POH denoted an airspeed of 108 knots, with landing and wing flaps retracted. The handbook noted that if the landing gear and/or wing flaps are extended, glide distance will be "severely" reduced. A power-off landing should be accomplished from the best glide airspeed of 108 knots. Landing gear and wing flaps should be extended once committed to landing. The POH specifiedthat a "spiral pattern" be established and, if altitude was available, to maintain 108 knots with flaps extended 10 degrees in the traffic pattern. The airplane was not equipped with, nor was it required to be equipped with, a cockpit voice or flight data recorder. In addition, the parameters that were recorded by the cockpit avionics did not included power or condition lever positions. As a result, the investigation was unable to confirm or exclude any movement of the power lever in an attempt to increase engine power before impact.