History of Flight
On October 5, 2014, about 1255 eastern daylight time, a Socata TBM 700 (850), N536EM, was forced landed onto a high school sports field near Fayetteville, Georgia. The commercial pilot received minor injuries and one passenger, his wife, had serious injuries. The airplane was registered to TBM 850 536 LLC and operated by the pilot under 14 Code of Federal Regulations Part 91 as a personal flight. Day visual meteorological conditions prevailed, and an instrument flight rules flight plan was filed. The flight departed Dekalb-Peachtree Airport (PDK), Atlanta, Georgia about 1240, destined for Pine Mountain, Georgia (PIM).
During cruise at 6,000 feet above mean sea level, the pilot observed an oil pressure message on the crew alerting system and a total loss of engine power. Air traffic control provided vectors to Falcon Field, Peachtree City, Georgia (FFC), but the pilot later reported he would not make the runway. An engine restart was not attempted. He feathered the propeller, placed the power lever in idle, and the condition lever to cut off. Landing gear and flaps remained retracted. Radar contact was lost, and the pilot force landed the airplane. The airplane collided with trees and the ground before coming to rest upright. No fire occurred. The pilot and his wife exited and were transported to a hospital.
Aircraft and Pilot Information
The pilot, age 66, held a commercial pilot certificate with airplane single engine land and instrument airplane ratings. He reported 4,244 total flight hours, including 411 hours in the accident make and model. He held a FAA third-class medical certificate with no limitations. He completed TBM 850 recurrent training at SIMCOM on January 24, 2014.
The accident airplane, a Socata TBM 700 (850), serial number 536, was manufactured in 2010. It was a single-engine low-wing monoplane of aluminum construction, with retractable tricycle landing gear and seating for six. It was powered by a Pratt & Whitney Canada PT6A-66D engine, rated at 850 shaft-horsepower, fitted with a Hartzell four-bladed constant-speed propeller. An annual inspection was completed on January 8, 2014; airframe total time at accident was 719.8 hours, with 135.6 hours since that inspection.
Meteorological Conditions
The 1253 surface weather observation at FFC, about 3 nautical miles west-northwest of the accident site, reported sky clear, wind calm, visibility 10 statute miles or greater, temperature 64°F, dew point 36°F, and altimeter setting 30.06 inches of mercury.
Wreckage and Impact
An FAA inspector examined the wreckage, which came to rest upright on level ground at a high school sports complex. The fuselage and both wings sustained structural damage; both wing fuel tanks were ruptured. Landing gear and wing flaps were retracted. Fuel spillage was evident. The propeller and gearbox were broken from the engine, which remained attached to the firewall. All major structural and flight control components were accounted for. Flight control continuity was established. The fuel tank selector handle was in the "L" (left) position.
Additional Information
The aircraft had integral fuel tanks in each wing, divided into inboard feeder and outboard storage sections. One-way valves allowed fuel flow inboard but prevented outflow. The feeder capacity was about 8.7 gallons.
The airplane was equipped with an automatic flight control system including autopilot and yaw damper. The yaw damper operated independently and could be engaged via a "YD" button. The autopilot could be activated with the "AP" key, which simultaneously activated the yaw damper. The yaw damper could be disengaged by using the manual electric yaw trim switch on the yoke or pressing the "YD" button. Recorded G1000 data did not include a discrete yaw damper engagement parameter. The data indicated extended flight in a slip condition, suggesting the yaw damper was disconnected while the autopilot was engaged. The pilot stated he was unaware of a side-slip before power loss.
On September 8, 2014, TBM issued Service Information 2014-006, providing an upgrade to G1000 software version 14.02, which included a new CAS caution message "AP ON YD OFF" and an aural warning. The accident airplane did not have this upgrade; the owner planned to install it at the next annual inspection.
The Pilot's Operating Handbook for the TBM 850 includes an engine failure checklist calling for an air start attempt. The pilot did not attempt an air start.
Data from the Garmin G1000 showed the airplane departing PDK about 1240. Autopilot engaged about 18 seconds after takeoff. During climb, lateral acceleration was near neutral. After leveling at 6,000 feet, the airplane entered a side-slip with lateral acceleration up to 0.17g and left bank of 8-10 degrees while maintaining a heading of about 190 degrees. At 1249:53, the airplane began a right turn with autopilot engaged. At 1250:16, engine power was lost. The autopilot was disconnected at 1251, and the airplane returned to near-coordinated flight during descent to the forced landing.
Examination of the fuel system revealed no obstructions or contamination. The engine was disassembled; no pre-impact anomalies were found. Impact damage prevented functional testing of the propeller governor. The rudder trim actuator was slightly left of neutral, but electrical testing showed normal operation.
Investigators found no evidence of pre-impact mechanical failure in the engine or fuel system that would have precluded normal operation.