Accident Overview
On March 13, 2013, at 1040 central daylight time, a New Piper Aircraft model PA-46-500TP airplane, N665KC, was substantially damaged when it impacted short of runway 34 (6,002 feet by 75 feet, asphalt) at 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 Part 91 as a personal flight. Visual meteorological conditions prevailed, and no flight plan was filed. The flight originated from West Houston Airport (IWS), Houston, Texas, at 1000.
Flight History
The flight instructor stated that the purpose was to practice engine failure procedures and power-off approaches. The accident occurred during the third approach. The first power-off approach required a go-around; the second ended in a full-stop landing. On the third approach, the instructor demonstrated a power-off approach. He climbed to 3,500 feet, reduced engine power, and began a spiral over the airport for left traffic to runway 34. During final approach, the airplane descended at a higher rate. The instructor attempted to increase engine power but did not hear or feel an indication of power increasing. The airplane impacted terrain short of the runway.
Ground marks were consistent with impact about 165 feet short of the runway. The airplane came to rest on the runway pavement oriented south. Both main landing gears separated; the fuselage remained intact but exhibited scraping damage aft of the passenger door. Both wings sustained damage from ground impact.
Investigation Findings
Flight and engine data were recovered from avionics units. The flight data showed the initial climb to about 6,000 feet pressure altitude, then a descent beginning around 1015 until the go-around. A second descent around 1025 terminated about 1029, consistent with a full-stop landing. The final takeoff began about 1033, climbing to about 3,200 feet pressure altitude with a maximum airspeed of about 160 knots. At 1037, a descent began; airspeed varied between 100 and 120 knots, with descent rates between 125 and 250 fpm. At about 1040:10, an abrupt heading change from 350° to 170° was recorded, consistent with ground impact. Airspeed decreased from 90 knots to zero.
Engine data indicated a reduction in propeller speed from about 2,000 rpm to 1,700 rpm beginning about 1039:00. Engine torque and gas generator speed decreased from about 150 foot-pounds to 30 foot-pounds and from 80% to 65%, respectively. This reduction profile was similar to that during the initial simulated power-off approach. Gas generator speed, torque, inter-turbine temperature, and oil pressure were stable at the end of the data.
Engine and Airframe Examination
A postaccident examination revealed no anomalies consistent with an inability to obtain engine power. The propeller assembly and engine cowling were intact with no blade damage. The engine housing, components, fuel and pneumatic lines were intact. The engine rotated freely; borescope examination found no internal blade damage. Engine control continuity was confirmed, and the power lever reverse lockout was functional. The electric fuel boost pump operated normally. The fuel bowl, lines, and filter were unremarkable; fuel appeared clean and free of contaminants. Functional testing and teardown of the fuel pump, fuel control unit, and fuel oil heat exchanger revealed no anomalies. Variations from standard settings were consistent with field adjustments.
The airplane had 734.7 total hours. The most recent annual inspection was on January 30, 2013, at 725.3 hours. An engine borescope inspection on February 12, 2013, at 726.0 hours showed no anomalies.
The Pilot's Operating Handbook (POH) specifies a best glide speed of 108 knots for engine failure, with power lever at idle, condition lever cut-off, and propeller feathered. It notes that extending landing gear or flaps severely reduces glide distance. A spiral pattern is recommended.
The airplane was not equipped with a cockpit voice or flight data recorder. The recorded parameters did not include power or condition lever positions. Therefore, the investigation was unable to confirm or exclude any movement of the power lever in an attempt to increase engine power before impact.