CEN11FA625

The pilot’s failure to properly trim the airplane’s rudder during cruise flight, which resulted in a prolonged uncoordinated flight condition, unporting of the fuel tank feed line, and subsequent fuel starvation and engine power loss. Contributing to the accident was the pilot’s failure to feather the engine’s propeller and maintain a proper glide airspeed following the loss of engine power.

During cruise flight, the pilot reported to an air traffic controller that the airplane was having engine fuel pressure problems. The controller advised the pilot of available airports for landing if necessary and asked the pilot's intentions. The pilot chose to continue the flight. GPS data recorded by an onboard avionics system indicated that the engine had momentarily lost total power about 20 seconds before the pilot reported a problem to the controller. About 7 minutes later, when the airplane was about 7,000 feet above ground level, the engine lost total power again, and power was not restored for the remainder of the flight. The pilot attempted to glide to an airport about 10 miles away, but the airplane crashed in a field about 3 miles from the airport. GPS data showed a loss of fuel pressure before each of the engine power losses and prolonged lateral g-forces consistent with a side-slip flight condition. The rudder trim tab was found displaced to the left about 3/8 inch. Flight testing and recorded flight data revealed that the rudder trim tab displacement was consistent with that required to achieve no side slip during a typical climb segment. The GPS and flight data indicated that the lateral g-forces increased as the airplane leveled off and accelerated, indicating that the automatic rudder trim feature of the yaw damper system was either not engaged or not operating. The recorded data indicated autopilot system engagement, which should have automatically engaged the yaw damper system. However, the data indicated the yaw damper was not engaged; the yaw damper could have subsequently been turned off by several means not recorded by the avionics system. Testing of the manual electric rudder (yaw) trim system revealed no anomalies, indicating that the pilot would have still been able to trim the airplane using the manual system. It is likely that the pilot's failure to properly trim the airplane's rudder led to a prolonged uncoordinated flight condition. Although the fuel tank system is designed to prevent unporting of the fuel lines during momentary periods of uncoordinated flight, it is not intended to do so for extended periods of uncoordinated flight. Therefore, the fuel tank feed line likely unported during the prolonged uncoordinated flight, which resulted in the subsequent loss of fuel pressure and engine power. The propeller and propeller controls were not in the feathered position, thus the windmilling propeller would have increased the airplane's descent rate during the glide portion of the flight. The glide airspeed used by the pilot was 20 knots below the airspeed recommended by the Pilot's Operating Handbook (POH), and the reduced airspeed also would have increased the airplane's descent rate during the glide. The flight and GPS data indicated that the airplane had a gliding range of about 16 nautical miles from the altitude where the final loss of engine power occurred; however, the glide performance was dependent on several factors, including feathering the propeller and maintaining the proper airspeed, neither of which the pilot did. Although the POH did not contain maximum range glide performance data with a windmilling propeller, based on the available information, it is likely that the airplane could have glided to the alternate airport about 10 miles away if the pilot had followed the proper procedures.

HISTORY OF FLIGHT On September 5, 2011, about 1833 central daylight time, a Socata TBM 700, N850SY, impacted terrain near Mount Pleasant, Wisconsin, during a forced landing following a loss of engine power. The pilot was fatally injured. The airplane was registered to Green Plane LLC, and operated by the pilot under the provisions of 14 Code of Federal Regulations (CFR) Part 91 as a personal flight. Visual flight rules (VFR) conditions prevailed for the flight, which operated on an instrument flight rules (IFR) flight plan. The flight originated from the Central Wisconsin Airport (CWA), Mosinee, WI, about 1626, and the intended destination was the Waukegan Regional Airport (UGN), Waukegan, Illinois. GPS track data, retrieved from the Garmin G1000 avionics system on the airplane, depicted the airplane departing CWA about 1626. The airplane remained in the CWA traffic pattern, performing two full stop landings at CWA prior to proceeding toward UGN. At 1653, the airplane took off from runway 8 at CWA and then proceeded southeast for about 5 nautical miles then south for 12 nautical miles where it crossed the Stevens Point Airport (STE) at an altitude of about 12,000 feet mean sea level (msl). After crossing STE, the airplane turned southeast to a heading of 130 degrees. During this portion of the flight, the airplane was in a climb reaching an altitude of about 19,000 feet msl at 1703:15. Data retrieved from the G1000 indicated that during the climb portion of the flight the roll angle and lateral acceleration were neutral. This indicated that the rudder trim was appropriately set for the climb portion of the flight. As the airplane leveled off and accelerated from the 140 knot indicated airspeed (IAS) for the climb to 200 knots IAS in level flight, the lateral acceleration steadily increased reaching values in excess of 0.15 g (positive values indicate a right sideslip), and the roll angle decreased to values less than -5 (positive values indicate a right roll), corresponding to a left bank in excess of 5 degrees angle of bank. The lateral acceleration remained elevated throughout the remainder of the flight. This and the recorded roll angles indicated that the airplane was flying in a slip. At 1811:30, the airplane began a descent from 19,000 feet msl and the IAS increased to about 225 knots. As the speed increased, the lateral acceleration increased to about 0.2g. At 1822:33, when the airplane was at 11,000 feet msl and about 7 nautical miles north of the Timmerman Airport (MWC), the avionics system recorded a momentary complete loss of engine torque. At this time the pilot was in communication with the General Mitchell International Airport (MKE) West Departure control position. At 1822:53, the pilot informed the controller that he had a problem with the airplane, later reporting that the problem was related to fuel pressure. The controller advised the pilot of three airports available for landing if necessary, and noted that the airplane had descended 1,600 feet below its assigned altitude of 11,000 feet msl. When the controller inquired as to the pilot's intentions, the pilot elected to continue the flight to UGN. The controller subsequently cleared the flight to 8,000 feet msl and the airplane maintained that altitude for approximately 3 minutes. At 1829:29, the avionics system recorded another complete loss of engine torque and the pilot reported the loss of power to the controller. Engine power was not restored for the remainder of the flight. At the time of the power loss, the airplane was about 10 miles west of the John H. Batten Airport (RAC), Racine, Wisconsin, at about 7,600 feet msl. The field elevation of RAC was 674 feet msl. At the time of the loss of engine power, the airplane was about 9.25 nautical miles west of RAC. GPS data showed that the airplane turned toward RAC and communications transcripts verified that the pilot was attempting to glide the airplane to RAC for a forced landing. The airplane descended at about 100 knots IAS toward RAC. The accident site and last recorded GPS position were about 3 miles southwest of the approach end of runway 4 at RAC. PERSONNEL INFORMATION The pilot held a commercial pilot certificate with single-engine land airplane and instrument-airplane ratings. He was issued a third-class airman medical certificate, with a restriction for corrective lenses, on April 28, 2011. The pilot had logged about 2,075 hours total flight time, with approximately 165 hours flight time in the accident airplane. The pilot's logbook included an endorsement dated February 5, 2011, that indicated the completion of a flight review as required by 14 CFR 61.56. Logbook and training records indicated that the pilot had received type specific training for the accident airplane from SimCom Training Centers, Orlando, Florida, in August of 2010, and from Turbine Solutions, Inc., St Cloud, Florida, in February of 2011. A review of the training records from Turbine Solutions indicated that the pilot had average knowledge of the airplane systems and procedures. The training record noted that the instructor discussed with the pilot the possibility of stepping down to a less complex airplane or having another pilot accompany on long cross country flights. The pilot completed the recurrent training at Turbine Solutions and was issued a completion certificate on February 5, 2011. AIRCRAFT INFORMATION The accident airplane was a Socata model TBM 700N, serial number 546. It was a single engine low-wing monoplane of mainly aluminum construction. It had a retractable tricycle landing gear and was configured to seat six occupants. The airplane was powered by a Pratt & Whitney Canada PT6A-66D engine, serial number RV0210, rated to produce 850 shaft-horsepower. The airframe and engine had accumulated 217.8 hours total time in-service at the time of the accident. The most recent annual inspection was completed on July 28, 2011, at 201.9 hours airframe time. According to maintenance records, the most recent maintenance action was accomplished on August 9, 2011 at 211.6 airframe hours, and involved troubleshooting for a flap problem. There were no subsequent entries in the maintenance logbook. METEOROLOGICAL INFORMATION Weather conditions recorded by the RAC Automated Surface Observing System (ASOS), located about 3 miles northeast of the accident site, at 1853, were: wind from 10 degrees at 11 knots gusting to 19 knots, visibility 10 miles, scattered clouds at 3,600 feet agl, temperature 14 degrees Celsius, dew point 7 degrees Celsius, and altimeter 30.15 inches of mercury. WRECKAGE AND IMPACT INFORMATION The airplane came to rest on a flat farm field facing east and the initial impact point was about 130 feet south of the main wreckage. The initial impact point was located on the north side of a road ditch on the north side of a highway. The fuselage was fractured at a position near the aft edge of the entry door. The tail surfaces including the elevators, horizontal stabilizers, rudder, and vertical stabilizer, remained attached to the aft fuselage. No damage was evident on the tail surfaces. The elevator trim tabs appeared to be in a neutral position and were aligned with the elevator. The rudder trim tab was displaced tab left about 10 mm (3/8"). The forward fuselage was predominately intact with crushing of the lower fuselage and buckling of the fuselage skins. The engine remained attached to the fuselage and there was bending of the firewall. Both wings remained partially attached to the fuselage. The wings remained predominately intact with crushing of portions of the leading edge. The left flap was separated at about half span. The outboard portion of that flap was located between the initial impact point and the main wreckage. The inboard portion of the flap remained attached to the wing. The left aileron remained attached to the wing by its outboard hinge. The right aileron remained