ERA14LA161

The pilot’s improper management of the fuel mixture and his failure to use the appropriate checklist and guidance during the flight, which resulted in an overrich mixture condition, carbon-fouling of the spark plugs, and a subsequent total loss of engine power during an attempted go-around.

The private pilot reported that, after departure, he and his pilot-rated passenger flew to a different airport to practice touch-and-go landings. He initially climbed the airplane to 2,500 ft above mean sea level (msl), but due to clouds, he descended to 1,400 ft msl. Upon arriving in the airport area, he descended to 1,200 ft msl and entered and then extended the downwind leg of the traffic pattern due to another airplane passing him. When the airplane entered the left base leg, the pilot determined that the airplane was "high," so he decided to conduct a "low approach" instead of a touch-and-go landing. He then set 12 inches of manifold pressure (mp). When the airplane had descended to about 400 ft msl, he decided to go around and "screwed the throttle in," but the engine did not respond. He then pitched the nose down to achieve the best glide airspeed and attempted to land straight ahead. The pilot stated that, at this point, the engine was still indicating 12 inches mp, and the propeller appeared to be "windmilling." He then pitched up to clear trees ahead and tried to land on a retention pond. The airplane then touched down on the water, skipped twice, slid up onto an embankment, struck a chain link fence and stacks of wooden shipping pallets, and came to rest. Examination of the airplane and engine did not reveal any evidence of preimpact mechanical malfunctions or failures. However, the spark plugs were found carbon-fouled, which can cause a loss of engine power. Testing of the ignition system, fuel injection system, and turbocharger system revealed no anomalies that would have resulted in carbon fouling. During the examination of the airplane, a Normal Procedures-Abbreviated Checklist was found on the pilot's seat. However, it was not the airplane manufacturer's checklist; it was labeled "FOR TRAINING PURPOSES ONLY"; and it did not contain any detailed guidance on power settings, use of the mixture control, or go-around procedures. All of this information was included in the airplane manufacturer's "Normal Procedures Checklist." Specifically, the checklist stated that, during cruise flight, the fuel mixture should be leaned as required. Further, review of the Pilot's Operating Handbook (POH) and Federal Aviation Administration-approved Airplane Flight Manual (AFM) revealed that, during cruise climb and flight, "the mixture must be adjusted" and that the pilot is responsible for leaning the mixture in cruise flight to lower the fuel flow. The POH and AFM also contained cruise performance charts, which included mixture setting information; however, these were not available to the pilot for reference during the flight. The pilot reported that he did not lean the mixture during the accident flight. Therefore, it is likely that the pilot's improper management of the fuel mixture resulted in an overrich mixture condition, carbon-fouling of the spark plugs, and the subsequent total loss of engine power at a low altitude and that, if he had used the correct checklist and leaned the mixture properly, the engine power loss could have been prevented.

Palatka Municipal Airport was a publicly-owned non-towered public use airport located 2 miles northwest of Palatka, Florida. The airport elevation was 48 feet above mean sea level and there were two runways oriented in a 9/27 and 17/35 configuration. Runway 9 was asphalt, and in good condition. The total length was 6,000 feet long and 100 feet wide. It was marked with basic markings in fair condition and was equipped with a 4-light precision approach path indicator located on the left side of the runway which provided a 3.00 degree glide path. Carbon Fouling of Spark Plugs Examination of the engine spark plugs revealed that they were covered in black sooty deposits (carbon fouled). Carbon deposits are conductive, and as they accumulate along the nose of a spark plug, they reduce the insulation resistance of the spark plug. As electricity always takes the path of least resistance a misfire may occur if a significant amount of carbon deposits accumulate. A spark will not form as electricity can track along the conductive carbon deposits to the metal shell of the spark plug rather than forming a spark across the electrode gap which has a very high resistance. According to Champion Aerospace Aviation Service Manual AV-6R, carbon fouling can be both fuel- and ignition-related. Typical fuel-related causes are over-rich fuel mixture, excessive idle or excessive operation at closed-throttle idle. Other causes might be improper idle mixture setting or improper (too cold) spark plug application. Ignition-related causes of carbon fouling include improper magneto timing, a failing lead or failed spark plug. Systems Component Testing The throttle and metering unit, fuel pump, fuel manifold valve, magnetos, turbochargers, pressure controller, wastegate actuator, and pressure relief valve were tested for functionality. The fuel system components were intact and demonstrated the ability to function properly on the test bench; however: the fuel pump produced a higher-than-specified pressure through all ranges. The test results were likely a result of fuel pump adjustments being made during fuel system setup on the airplane. The throttle body/metering unit met the specified fuel flow for a given throttle angle with the exception of 2 degree and 74 degree throttle settings. The out of specification observations at the 2 degree setting were likely due to idle RPM/mixture adjustments made on the throttle body while installed on the airplane. The fuel manifold valve, fuel injector lines, and nozzles met the specified test parameters throughout the full test range. Though some of the fuel system components (without adjustments and as received) did not meet new product specifications, the components demonstrated their ability to pump, meter, and distribute fuel at their adjusted settings. No anomalies were noted during testing of the ignition system components that would have precluded their normal operation, and examination of the sparkplugs revealed that they were an appropriate sparkplug for use in the Continental TSIO-550-C11B engine. No anomalies were noted during examination and testing of the turbocharger components that would have precluded their normal operation. Pilot Statements During a postaccident interview, the pilot advised that usually he would run 18" mp in the pattern which would give him 115 knots. On base leg, his normal practice was to reduce to 12" mp which would enable him to descend at 500 feet per minute. At his minimum descent altitude or decision height, he would "screw the power back in." he would also on the 45-degree entry "dump 1st flap on downwind or base," then on final approach the "second set." He advised that on the day of the accident though, he could not do his normal power settings where he normally would do them in the pattern because of the traffic. He advised that normally in cruise flight he would have "leaned the machine" to 31" mp, at 2,450 rpm, which would give him 17 pounds an hour fuel flow, and he would look at the cylinder head temperatures and turbine inlet temperatures. He did not however lean the mixture on the flight from SGJ to 28J. When asked if he noticed what the fuel flow indication was on the Garmin G1000 prior to the loss of engine power, he said that he did not notice. He would "go to" full rich on landing. When asked if he may have had the vapor suppression switch on, or the backup fuel pump armed, he stated that he did not think so. He also advised that on three different occasions, he had the engine quit while the airplane was on the ground. The first time was when he had the airplane for 40 hours. He landed at an airport and the engine quit during landing rollout. The second time the engine quit might have been in Venice, Florida about a year before the accident, where after landing during taxi to the ramp, the engine quit again. After that occurrence, he took it to Southwest Aero but, they could not find anything wrong with the airplane. Checklist Usage During the examination of the airplane, a checklist was found on the pilot's seat. Examination of the checklist revealed that it was not the checklist issued by Cessna Aircraft for the airplane but was labeled "Normal Procedures-Abbreviated Checklist." Further examination of the checklist also revealed that it was labeled "FOR TRAINING PURPOSES ONLY," and did not contain any detailed guidance regarding spark plug fouling, power settings, use of mixture control, or balked landing (Go Around) procedures. Examination of the "NORMAL PROCEDURES CHECKLISTS" published by Cessna Aircraft for use with the airplane revealed that they contained detailed guidance for minor spark plug fouling as well as power settings, detailed instructions for use of the mixture control, and balked landing (Go Around) procedures which required that the backup fuel pump be in the "ARM" position. Pilot's Operating Handbook Review of the Pilot's Operating Handbook (POH) and FAA Approved Airplane Flight Manual (AFM) revealed that, in cruise flight, and cruise climb, "the mixture must be adjusted" and "The pilot is responsible to lean the mixture in cruise for lower fuel flow." Further review of the POH/AFM revealed that it contained cruise performance charts which listed mixture setting information, lean of peak engine operation data, and mixture control, backup fuel pump, and vapor suppression system operating information. . Toxicological testing of the pilot and pilot-rated passenger was conducted at the FAA Bioaeronautical Sciences Research Laboratory, Oklahoma City, Oklahoma. The provided specimens from the pilot were insufficient for analysis. No hazardous compounds or drugs of abuse were detected in the provided specimens for the pilot-rated passenger. An Autopsy was performed on the pilot-rated passenger by the State of Florida, Medical Examiner District 14. The listed probable cause of death was injuries sustained in airplane crash. Examination of the Accident Site The airplane initially touched down on the waters of a retention pond that was located on the east side of the airport, skipped twice off the surface of the water, then slid up on an embankment, struck a chain link fence, and then stacks of wooden shipping pallets before coming to rest approximately 30 feet from a home improvement store. Examination of the Airplane The lower engine cowling was deformed up and aft, and the top cowling was separated from the lower cowl at its piano hinge. The three-bladed propeller remained attached to the engine crankshaft. The two blades that were in 4 o'clock and 8 o'clock positions below the propeller hub were bent aft around the cowling. The third blade was in the 12 o'clock position and sustained two small leading edge dents. None of the propeller blades displayed leading edge gouging or evidence of s-bending. The cambered sides of the bent blades were scraped. The spinner remained attached to the propeller