Cessna Aircraft Co LC41-550FG N717RR accident near Palatka, Florida

Probable cause

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.

NTSB analysis

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.

Text from the NTSB. Open the NTSB docket for ERA14LA161 for the full record.