Accident Overview
On March 3, 2012, at approximately 1440 Eastern Standard Time, a Mooney M20M, registration N486KC, sustained substantial damage during a forced landing in a field near Amisville, Virginia. The aircraft was owned and operated by a private individual. Both the certificated private pilot and a passenger were seriously injured. The personal flight was conducted under Part 91 of the Federal Aviation Regulations. Visual meteorological conditions prevailed, and an instrument flight rules flight plan had been filed.
Flight History
The flight departed Georgetown County Airport, Georgetown, South Carolina, around 1130, destined for Hagerstown Regional Airport in Hagerstown, Maryland. The pilot reported that before departure, the aircraft was filled with fuel, and he received a weather briefing and filed a flight plan. During the initial part of the trip, the airplane cruised at 9,000 feet to remain above cloud layers. After clearing over Virginia, when the flight was approximately 100 miles (30 minutes) from the destination, air traffic control instructed the pilot to descend to 5,000 feet, which he acknowledged. While descending, the aircraft encountered moderate to severe turbulence. The pilot reduced throttle to slow to maneuvering speed. When he attempted to add throttle, there was no response; the engine had lost all power. The pilot then pushed the throttle fully forward, which activated the fuel boost pump, and set the mixture to full rich, but the engine did not recover.
Emergency Response
The pilot declared an emergency with air traffic control, who provided a vector to the nearest airport. However, due to mountainous terrain, the pilot could not glide to that airport. He identified several small fields and executed a forced landing to one of them. During the landing, the aircraft struck a fence and trees.
Pilot Observations
The pilot stated that he did not believe the power loss was due to a mechanical failure, as the engine had been running smoothly before the event. He suspected a fuel or air issue, possibly related to the severe turbulence. He noted that the sky was clear and the aircraft did not encounter clouds or precipitation during the descent or before the power loss. The pilot thought the right fuel tank was selected at the time of the power loss but could not be certain. He estimated the fuel tanks were half full and had been switching tanks every 30 minutes. He did not switch tanks after the power loss due to focusing on landing. At the time of the power loss, the mixture had been properly leaned based on turbine inlet temperature.
Wreckage Examination
A Federal Aviation Administration inspector examined the wreckage. The impact sequence compromised the left and right wing fuel tanks, and a postcrash fire consumed a majority of the wreckage. The four-seat, low-wing, retractable tricycle-gear airplane, serial number 27-0288, was manufactured in 2000. It was powered by a Lycoming TIO-540, 270-horsepower engine. Review of the aircraft logbooks indicated that the most recent annual inspection was completed on September 1, 2011. At that time, the airframe and engine had accumulated 1,154.5 total hours since new. The aircraft had flown approximately 60 hours since that inspection.
Engine Examination
The engine remained attached to the airframe via the mounts, but the propeller had separated. The engine cowling, cockpit, fuel system, and induction system were fire-damaged. The throttle quadrant was identified but had cable separation from fire and impact. The fuel selector was found in the left main fuel tank position, but the preimpact position could not be positively determined.
The engine was separated for further inspection. Valve covers, magnetos, fuel nozzles, and top spark plugs were removed. Spark plug electrodes were intact and light to dark gray. Fuel nozzles 1, 3, 4, and 5 were unobstructed; nozzles 2 and 6 contained debris consistent with fire damage. The magnetos had thermal damage and could not be tested. The crankshaft could not be rotated by hand. The accessory section showed thermal and corrosion damage to the gears. Bottom spark plugs were intact and similarly colored. The turbocharger wastegate was three-fourths open; the cold section was fire-damaged, while the hot section impeller housing showed no rotational scoring.
Fire had melted sections of the engine case bottom, including the oil sump and data plate. Borescope examination through drilled holes revealed no evidence of catastrophic failure in the cylinders, camshaft, or crankshaft.
Additional Findings
Airworthiness Directive 85-24-03 and Mooney Service Bulletin M-20-230 were noted in reports of fuel and water trapped between ribs due to sealed rib drain holes, particularly in resealed tanks, potentially releasing during severe turbulence. However, these directives applied to older Mooney models and were not applicable to the accident aircraft. For this make and model, the fuel tank inspection was included in the service manual. The accident airplane's right fuel tank had been repaired in 2002 and 2010. Postcrash fire damage prevented examination of the wing fuel tanks for rib drain hole blockage.